2021 Vol. 40, No. 4
Display Method:
2021, 40(4): 555-564.
Abstract:
Daily changes of dissolved inorganic carbon in river mainly are controlled by carbonate back-precipitation，aquatic photosynthesis and CO2 degassing at water-air interface. Dissolved inorganic carbon uptake by aquatic photosynthesis is a part of karst carbon sink，and the size of degassing proportion values acts as the determinant factor for carbon sink stability. To analysis of the loss of bicarbonate caused by aquatic photosynthesis and relevant calcite precipitation processes，high resolution monitoring for water chemistry and high-frequency water sampling in daily scale were conducted in a 15 km-long section between Shengli and Guanyan in middle course of Lijiang River. The results showed that the flux of photosynthesis uptake of dissolved inorganic carbon in monitoring section is about 859 kgC?d-1. DIC removal value by photosynthesis and calcite precipitation value are 2.06 t?（d?km）-1 and 0.78 t?（d?km）-1， respectively. CO2 degassing value accounts for 28.4 % of total carbon removal，namely，approximately 70% of carbon removal was converted into organic carbon and precipitated in riverbed in form of calcite，thus constitute a part of karst carbon sink. DIC removal accounts for about 6.0 % of total input，in which 1.7 % returned to the atmosphere in the form of CO2，indicating DIC uptake by aquatic photosynthesis during the summer low water level can restrain CO2 degassing process in air-water interface effectively during the day time. The low degassing proportion suggested that DIC in water body of Lijiang River is relatively stable.
Daily changes of dissolved inorganic carbon in river mainly are controlled by carbonate back-precipitation，aquatic photosynthesis and CO2 degassing at water-air interface. Dissolved inorganic carbon uptake by aquatic photosynthesis is a part of karst carbon sink，and the size of degassing proportion values acts as the determinant factor for carbon sink stability. To analysis of the loss of bicarbonate caused by aquatic photosynthesis and relevant calcite precipitation processes，high resolution monitoring for water chemistry and high-frequency water sampling in daily scale were conducted in a 15 km-long section between Shengli and Guanyan in middle course of Lijiang River. The results showed that the flux of photosynthesis uptake of dissolved inorganic carbon in monitoring section is about 859 kgC?d-1. DIC removal value by photosynthesis and calcite precipitation value are 2.06 t?（d?km）-1 and 0.78 t?（d?km）-1， respectively. CO2 degassing value accounts for 28.4 % of total carbon removal，namely，approximately 70% of carbon removal was converted into organic carbon and precipitated in riverbed in form of calcite，thus constitute a part of karst carbon sink. DIC removal accounts for about 6.0 % of total input，in which 1.7 % returned to the atmosphere in the form of CO2，indicating DIC uptake by aquatic photosynthesis during the summer low water level can restrain CO2 degassing process in air-water interface effectively during the day time. The low degassing proportion suggested that DIC in water body of Lijiang River is relatively stable.
2021, 40(4): 565-571.
Abstract:
The objective of this work was to understand the karst development potential of carbonate strata in southern Jiangsu，and provide quantitative data for relevant research. Some representative rock samples were collected and made into test specimens of uniform specifications，which were prepared to a hydrological year dissolution test. The results show that，（1） The average dissolution rate of the carbonate rock in this area is about 1.42 mm/ka，which is at a low level compared with other areas in China，roughly equivalent to 1/30 of that of southwestern China mainland and slightly higher than that of the karst areas in northern China.（2） The experiment proves that the Permian and Triassic carbonate rocks in southern Jiangsu Province have the strongest dissolution，which provides a geological basis for explaining the karst phenomenon in the above-mentioned stratigraphic zones. （3）The dissolution of rock is closely related to Ca content，which is affected by the mineral composition and micro-structure of the rock. Generally，high-Ca carbonate rock has high dissolubility.（4） Two key factors determining the development of karst are rock dissolution and hydrodynamic condition.The Yixing area meets both conditions，so karst developed well.
The objective of this work was to understand the karst development potential of carbonate strata in southern Jiangsu，and provide quantitative data for relevant research. Some representative rock samples were collected and made into test specimens of uniform specifications，which were prepared to a hydrological year dissolution test. The results show that，（1） The average dissolution rate of the carbonate rock in this area is about 1.42 mm/ka，which is at a low level compared with other areas in China，roughly equivalent to 1/30 of that of southwestern China mainland and slightly higher than that of the karst areas in northern China.（2） The experiment proves that the Permian and Triassic carbonate rocks in southern Jiangsu Province have the strongest dissolution，which provides a geological basis for explaining the karst phenomenon in the above-mentioned stratigraphic zones. （3）The dissolution of rock is closely related to Ca content，which is affected by the mineral composition and micro-structure of the rock. Generally，high-Ca carbonate rock has high dissolubility.（4） Two key factors determining the development of karst are rock dissolution and hydrodynamic condition.The Yixing area meets both conditions，so karst developed well.
2021, 40(4): 572-579.
Abstract:
CO2 can be absorbed by water and transformed into HCO3-. This process is well known as the buffering of carbonate system，which can be quantified using the Revelle factor（R）. CO2 released by terrestrial freshwater systems is an important component of the global carbon cycle. On the one hand，CO2 released by lake water is from the input of carbonate weathering products in the basin；on the other hand，the buffering effect of carbonate is an important factor regulating CO2 release of inland water. These two conclusions seem to be contradictory. In order to reveal the effect of carbonate cycling on CO2 in freshwater lakes，in this study， we investigated the variation of Revelle factor R in a stratified lake（Baihua lake）located in carbonate area，and compared to the data obtained from lakes from non-karst areas. The results show that the average of Revelle factor in the lake water is 20.1± 8.1（8.0-50.0），which is larger than 10.0（8.0-15.0）in the surface sea water and also much larger than 3.9±3.9 in lakes in non-karst areas. A higher Revelle factor means a weaker CO2 buffering capacity. The maximum value of R，46.4，occurred in the thermocline in summer，where corresponding variations of inorganic carbon concentration（2.1 mmol?L-1），ratio of total inorganic carbon to alkalinity（1.0），ratio of CO2/CO3（1.0）and pH （8.38）are well coincident with the theoretical values. This consistency indicates that chemical equilibrium of carbonate is primary factor controlling Revelle factor of lake water. Lake waters with lower pH in non-karst areas could dissolve carbonate and then raise pH and alkalinity，thus elevate the Revelle factor to the maximum value while dissolution of carbonate reaches an equilibrium. Thereafter，Revelle factor will decrease and the buffering capability resulted by the metabolism increase，regardless of carbonate precipitation due to photosynthesis or carbonate dissolution during respiration.
CO2 can be absorbed by water and transformed into HCO3-. This process is well known as the buffering of carbonate system，which can be quantified using the Revelle factor（R）. CO2 released by terrestrial freshwater systems is an important component of the global carbon cycle. On the one hand，CO2 released by lake water is from the input of carbonate weathering products in the basin；on the other hand，the buffering effect of carbonate is an important factor regulating CO2 release of inland water. These two conclusions seem to be contradictory. In order to reveal the effect of carbonate cycling on CO2 in freshwater lakes，in this study， we investigated the variation of Revelle factor R in a stratified lake（Baihua lake）located in carbonate area，and compared to the data obtained from lakes from non-karst areas. The results show that the average of Revelle factor in the lake water is 20.1± 8.1（8.0-50.0），which is larger than 10.0（8.0-15.0）in the surface sea water and also much larger than 3.9±3.9 in lakes in non-karst areas. A higher Revelle factor means a weaker CO2 buffering capacity. The maximum value of R，46.4，occurred in the thermocline in summer，where corresponding variations of inorganic carbon concentration（2.1 mmol?L-1），ratio of total inorganic carbon to alkalinity（1.0），ratio of CO2/CO3（1.0）and pH （8.38）are well coincident with the theoretical values. This consistency indicates that chemical equilibrium of carbonate is primary factor controlling Revelle factor of lake water. Lake waters with lower pH in non-karst areas could dissolve carbonate and then raise pH and alkalinity，thus elevate the Revelle factor to the maximum value while dissolution of carbonate reaches an equilibrium. Thereafter，Revelle factor will decrease and the buffering capability resulted by the metabolism increase，regardless of carbonate precipitation due to photosynthesis or carbonate dissolution during respiration.
2021, 40(4): 580-591.
Abstract:
In order to understand the characteristics of CO2 water-soil-gas at different scales in the karst area of Jiguan cave，western Henan，and to explore the relationship of CO2 migration in the karst critical zone system， we used the solid-state sensor method to monitor the change of overlying soil CO2 with high time resolution and collected the data every 15 minutes in Jiguan cave，Henan， from May 2019 to October 2020. Combined with monthly air CO2 data collected in the cave， the chemistry index of cave water， and monitoring data of rainfall and temperature for a systematic and comprehensive analysis，the result showed that，（1）The soil CO2 concentration，the air CO2 collected in the cave，and the chemistry index of cave water had obvious seasonal changes，all of which are high in summer and autumn and low in winter and spring.（2）On the day and night scale，the soil CO2 concentration during the day was higher than that at night.The difference between day and night was the largest in summer and the smallest in winter. The day and night change lagged behind air temperature and soil temperature by about 6 hours.The changes of air CO2 collected in the cave，the concentration of water ions in the cave ，and the chemistry index of cave water were synchronized in the day and night changes.（3）Under the scale of heavy rainfall（single rainfall was 42.2 mm），soil moisture and soil temperature can respond to rainfall changes in time，while the response of soil CO2 changes to rainfall lagged about 2 hours.Changes in cave water and cave CO2 were similar to changes in soil CO2.（4）The correlation coefficients of soil CO2，soil temperature and soil moisture based on monthly average values were 0.67and 0.031，respectively. In the vertical direction，the order of seasonal change of CO2 concentration was soil> cave> atmosphere. The lag of soil CO2 on air temperature and soil temperature day and night was affected by the photosynthesis intensity of the overlying vegetation. CO2 is mainly degassed and deposited in the cave water transportation，replenishing the air CO2 in the cave. During heavy rainfall，soil CO2 is controlled by soil temperature and humidity changes，but is more dominated by soil temperature on a long-term scale，with less soil moisture influences.In order to understand the characteristics of CO2 water-soil-gas at different scales in the karst area of Jiguan cave，western Henan，and to explore the relationship of CO2 migration in the karst critical zone system， we used the solid-state sensor method to monitor the change of overlying soil CO2 with high time resolution and collected the data every 15 minutes in Jiguan cave，Henan， from May 2019 to October 2020. Combined with monthly air CO2 data collected in the cave， the chemistry index of cave water， and monitoring data of rainfall and temperature for a systematic and comprehensive analysis，the result showed that，（1）The soil CO2 concentration，the air CO2 collected in the cave，and the chemistry index of cave water had obvious seasonal changes，all of which are high in summer and autumn and low in winter and spring.（2）On the day and night scale，the soil CO2 concentration during the day was higher than that at night.The difference between day and night was the largest in summer and the smallest in winter. The day and night change lagged behind air temperature and soil temperature by about 6 hours.The changes of air CO2 collected in the cave，the concentration of water ions in the cave ，and the chemistry index of cave water were synchronized in the day and night changes.（3）Under the scale of heavy rainfall（single rainfall was 42.2 mm），soil moisture and soil temperature can respond to rainfall changes in time，while the response of soil CO2 changes to rainfall lagged about 2 hours.Changes in cave water and cave CO2 were similar to changes in soil CO2.（4）The correlation coefficients of soil CO2，soil temperature and soil moisture based on monthly average values were 0.67and 0.031，respectively. In the vertical direction，the order of seasonal change of CO2 concentration was soil> cave> atmosphere. The lag of soil CO2 on air temperature and soil temperature day and night was affected by the photosynthesis intensity of the overlying vegetation. CO2 is mainly degassed and deposited in the cave water transportation，replenishing the air CO2 in the cave. During heavy rainfall，soil CO2 is controlled by soil temperature and humidity changes，but is more dominated by soil temperature on a long-term scale，with less soil moisture influences.
In order to understand the characteristics of CO2 water-soil-gas at different scales in the karst area of Jiguan cave，western Henan，and to explore the relationship of CO2 migration in the karst critical zone system， we used the solid-state sensor method to monitor the change of overlying soil CO2 with high time resolution and collected the data every 15 minutes in Jiguan cave，Henan， from May 2019 to October 2020. Combined with monthly air CO2 data collected in the cave， the chemistry index of cave water， and monitoring data of rainfall and temperature for a systematic and comprehensive analysis，the result showed that，（1）The soil CO2 concentration，the air CO2 collected in the cave，and the chemistry index of cave water had obvious seasonal changes，all of which are high in summer and autumn and low in winter and spring.（2）On the day and night scale，the soil CO2 concentration during the day was higher than that at night.The difference between day and night was the largest in summer and the smallest in winter. The day and night change lagged behind air temperature and soil temperature by about 6 hours.The changes of air CO2 collected in the cave，the concentration of water ions in the cave ，and the chemistry index of cave water were synchronized in the day and night changes.（3）Under the scale of heavy rainfall（single rainfall was 42.2 mm），soil moisture and soil temperature can respond to rainfall changes in time，while the response of soil CO2 changes to rainfall lagged about 2 hours.Changes in cave water and cave CO2 were similar to changes in soil CO2.（4）The correlation coefficients of soil CO2，soil temperature and soil moisture based on monthly average values were 0.67and 0.031，respectively. In the vertical direction，the order of seasonal change of CO2 concentration was soil> cave> atmosphere. The lag of soil CO2 on air temperature and soil temperature day and night was affected by the photosynthesis intensity of the overlying vegetation. CO2 is mainly degassed and deposited in the cave water transportation，replenishing the air CO2 in the cave. During heavy rainfall，soil CO2 is controlled by soil temperature and humidity changes，but is more dominated by soil temperature on a long-term scale，with less soil moisture influences.In order to understand the characteristics of CO2 water-soil-gas at different scales in the karst area of Jiguan cave，western Henan，and to explore the relationship of CO2 migration in the karst critical zone system， we used the solid-state sensor method to monitor the change of overlying soil CO2 with high time resolution and collected the data every 15 minutes in Jiguan cave，Henan， from May 2019 to October 2020. Combined with monthly air CO2 data collected in the cave， the chemistry index of cave water， and monitoring data of rainfall and temperature for a systematic and comprehensive analysis，the result showed that，（1）The soil CO2 concentration，the air CO2 collected in the cave，and the chemistry index of cave water had obvious seasonal changes，all of which are high in summer and autumn and low in winter and spring.（2）On the day and night scale，the soil CO2 concentration during the day was higher than that at night.The difference between day and night was the largest in summer and the smallest in winter. The day and night change lagged behind air temperature and soil temperature by about 6 hours.The changes of air CO2 collected in the cave，the concentration of water ions in the cave ，and the chemistry index of cave water were synchronized in the day and night changes.（3）Under the scale of heavy rainfall（single rainfall was 42.2 mm），soil moisture and soil temperature can respond to rainfall changes in time，while the response of soil CO2 changes to rainfall lagged about 2 hours.Changes in cave water and cave CO2 were similar to changes in soil CO2.（4）The correlation coefficients of soil CO2，soil temperature and soil moisture based on monthly average values were 0.67and 0.031，respectively. In the vertical direction，the order of seasonal change of CO2 concentration was soil> cave> atmosphere. The lag of soil CO2 on air temperature and soil temperature day and night was affected by the photosynthesis intensity of the overlying vegetation. CO2 is mainly degassed and deposited in the cave water transportation，replenishing the air CO2 in the cave. During heavy rainfall，soil CO2 is controlled by soil temperature and humidity changes，but is more dominated by soil temperature on a long-term scale，with less soil moisture influences.
2021, 40(4): 592-599.
Abstract:
It is of great value to understand the variation amplitude and temporal dynamics of soil respiration on a global scale so as to accurately predict the change of soil respiration under future climate scenarios， and to evaluate the carbon neutrality goals and technical approaches. In this study，the static chamber/gas chromatography were used to establish soil CO2 flux and δ13C CO2seasonal variation in the typical karst area of Maocun village.This study mainly aims to reveal the influence mechanism of soil CO2 and δ13C CO2 on environmental factors under field conditions Guilin.The influence of environmental factors on soil CO2 flux and δ13C CO2 were determined by monitoring atmospheric temperature， pressure， soil temperature and other environmental parameters. The monitoring results showed that the seasonal variation of soil CO2 flux in the study area was obviously high in summer and low in winter， and the soil CO2 flux at 10 cm in summer was significantly higher than that at 0 cm in the surface layer， while there was no significant difference in winter. Moreover， the soil Q10 value increased from 1.90 to 2.39 when the depth varies from 0 cm to 10 cm， indicating that the soil respiration mainly came from this depth range. Soil temperature is the main environmental factor affecting the change of soil CO2 flux， and the two show an obvious positive correlation. Copmared with 10 cm，the CO2 at 0 cm surface layer was also affected by the dilution of diffusion. Because the diffusion coefficient of 12CO2 is greater than 13CO2， the soil δ13C CO2 is lighter than the atmospheric δ13C during the monitoring period， which has obvious seasonal characteristics of being lighter in summer and heavier in winter， and the δ13C CO2 at 10 cm is significantly lighter than that at 0 cm.
It is of great value to understand the variation amplitude and temporal dynamics of soil respiration on a global scale so as to accurately predict the change of soil respiration under future climate scenarios， and to evaluate the carbon neutrality goals and technical approaches. In this study，the static chamber/gas chromatography were used to establish soil CO2 flux and δ13C CO2seasonal variation in the typical karst area of Maocun village.This study mainly aims to reveal the influence mechanism of soil CO2 and δ13C CO2 on environmental factors under field conditions Guilin.The influence of environmental factors on soil CO2 flux and δ13C CO2 were determined by monitoring atmospheric temperature， pressure， soil temperature and other environmental parameters. The monitoring results showed that the seasonal variation of soil CO2 flux in the study area was obviously high in summer and low in winter， and the soil CO2 flux at 10 cm in summer was significantly higher than that at 0 cm in the surface layer， while there was no significant difference in winter. Moreover， the soil Q10 value increased from 1.90 to 2.39 when the depth varies from 0 cm to 10 cm， indicating that the soil respiration mainly came from this depth range. Soil temperature is the main environmental factor affecting the change of soil CO2 flux， and the two show an obvious positive correlation. Copmared with 10 cm，the CO2 at 0 cm surface layer was also affected by the dilution of diffusion. Because the diffusion coefficient of 12CO2 is greater than 13CO2， the soil δ13C CO2 is lighter than the atmospheric δ13C during the monitoring period， which has obvious seasonal characteristics of being lighter in summer and heavier in winter， and the δ13C CO2 at 10 cm is significantly lighter than that at 0 cm.
2021, 40(4): 600-607.
Abstract:
In order to study the characteristics of vertical carbon migration in open karst cave system and its influencing factors. From November 2017 to November 2018， taking Liangfeng cave in the underground river basin of Maocun village， Guilin as the research object，we conducted real-time monitoring of the atmospheric environment and cave environment in the field. At the same time, a test piece dissolution experiment was carried out at 30 cm and 60 cm of the cave overlying soil ，and the test piece dissolution and drip degassing monitoring were carried out simultaneously in the cave so as to measure the CO2 concentration and δ13C—CO2 value in the main process of vertical carbon migration.The results show，（1）The "atmosphere-soil-cave" vertical carbon migration system can affect the CO2 distribution pattern inside the cave system together with cave ventilation. The change of the ventilation direction of the cave depends on the temperature difference between the inside and outside of the cave.The ventilation direction in the cold season with little rain was from outside the cave to the inside of the cave. At this time， the vertical carbon migration ability was weak， and the distribution of CO2 inside cave was dominated by the ventilation of cave entrance. From early March to mid-September， the temperature difference between inside and outside of the cave gradually transitioned and reversed. The ventilation direction of the cave entrance was from the inside to the outside， with high rainfall intensity. The vertical carbon migration was active and dominated the CO2 distribution in the cave； （2） The intensity of soil respiration in the karst critical zone determines the amount of carbon that can be transferred by the vertical carbon migration system. The seasonal variation of CO2 distribution in the cave was essentially the response of the external environment to the vertical carbon migration system and cave ventilation； （3） The dissolution experiment of carbonate rock on the overlying roof of the cave shows that the dissolution under the soil can weaken the role of soil carbon source. The dissolution rate of carbonate rock at 30 cm and 60 cm of soil are 0.48 mol·m-2·a-1 and 0.96 mol·m-2·a-1， respectively； while the carbonate rock precipitation-degassing rate at the monitoring point of the first cave hall was 49.35 mol·m-2·a-1 and 9.07 mol·m-2·a-1 in the second cave hall. The drip degrassing of dissolved soil CO2 transported by the vertical carbon migration system to the inside of the cave was significantly.
In order to study the characteristics of vertical carbon migration in open karst cave system and its influencing factors. From November 2017 to November 2018， taking Liangfeng cave in the underground river basin of Maocun village， Guilin as the research object，we conducted real-time monitoring of the atmospheric environment and cave environment in the field. At the same time, a test piece dissolution experiment was carried out at 30 cm and 60 cm of the cave overlying soil ，and the test piece dissolution and drip degassing monitoring were carried out simultaneously in the cave so as to measure the CO2 concentration and δ13C—CO2 value in the main process of vertical carbon migration.The results show，（1）The "atmosphere-soil-cave" vertical carbon migration system can affect the CO2 distribution pattern inside the cave system together with cave ventilation. The change of the ventilation direction of the cave depends on the temperature difference between the inside and outside of the cave.The ventilation direction in the cold season with little rain was from outside the cave to the inside of the cave. At this time， the vertical carbon migration ability was weak， and the distribution of CO2 inside cave was dominated by the ventilation of cave entrance. From early March to mid-September， the temperature difference between inside and outside of the cave gradually transitioned and reversed. The ventilation direction of the cave entrance was from the inside to the outside， with high rainfall intensity. The vertical carbon migration was active and dominated the CO2 distribution in the cave； （2） The intensity of soil respiration in the karst critical zone determines the amount of carbon that can be transferred by the vertical carbon migration system. The seasonal variation of CO2 distribution in the cave was essentially the response of the external environment to the vertical carbon migration system and cave ventilation； （3） The dissolution experiment of carbonate rock on the overlying roof of the cave shows that the dissolution under the soil can weaken the role of soil carbon source. The dissolution rate of carbonate rock at 30 cm and 60 cm of soil are 0.48 mol·m-2·a-1 and 0.96 mol·m-2·a-1， respectively； while the carbonate rock precipitation-degassing rate at the monitoring point of the first cave hall was 49.35 mol·m-2·a-1 and 9.07 mol·m-2·a-1 in the second cave hall. The drip degrassing of dissolved soil CO2 transported by the vertical carbon migration system to the inside of the cave was significantly.
2021, 40(4): 608-616.
Abstract:
The dissolution of carbonate rocks by sulfuric acid and nitric acid would reduce the amount of karst carbon sink， however， the quantitative relationship between these acids and carbon sink needs further study. Based on the concentrations of SO42-and NO3- in field water，this paper designed carbonic acid（0.033 mol?L-1 ）+ sulfuric acid + nitric acid（0.1-1.7 mmol?L-1）（CSN acid）and sulfuric acid + nitric acid（0.1-1.7 mmol?L-1）（SN acid）dissolution experiment on carbonate rocks，and the experiment lasted 144 hours. The results show that the dissolution rates of micrite and dolomite in the CSN acid are both higher than that in the SN acid.In the CSN acid，the dissolution rate of micrite is generally higher than that of dolomite， with average values of 1.34 mg·（cm2?d）-1 and 1.21 mg·（cm2?d）-1， respectively. In the SN acid，the dissolution rates of micrite and dolomite have little difference，and their average values are 0.92 mg·（cm2?d）-1 and 0.93 mg·（cm2?d）-1， respectively. The HCO3- concentration corresponds to the result of the dissolution rate. The average HCO3- values generated by dissolution of micrite and dolomite in the CSN acid solution are 1.43 mmol?L-1 and 1.33 mmol?L-1， while the average values of HCO3- generated by dissolution of micrite and dolomite in the SN acid are 0.33 mmol?L-1 and 0.39 mmol?L-1. The concentration of HCO3- in the CSN acid decreases with the increase of acid concentration，while the concentration in the SN acid increases with the increase of acid concentration. When the concentration of SO42- and NO3- is 0.1-0.3 mmol?L-1， the dissolution rate of carbonic acid to dolomite accounts for 75.89 %-58.64%， and the dissolution rate of carbonic acid to micrite accounts for 80.21%-59.06%.When the concentrations of SO42- and NO3- are more than 0.44 mmol?L-1，the dissolution rate of carbonate rock by carbonate acid will be less than 50%.When the concentrations of SO42- and NO3- are 0.0-0.2 mmol?L-1， the field measured data is basically consistent with the simulated data. However，when the concentration of SO42- and NO3- is higher than 0.2 mmol?L-1，the field measured data is higher than the simulated data. These results indicate that nitric acid and sulfuric acid significantly affect the dissolution of carbonate rock，which could provide references for the effects of other acids on karst carbon sink.
The dissolution of carbonate rocks by sulfuric acid and nitric acid would reduce the amount of karst carbon sink， however， the quantitative relationship between these acids and carbon sink needs further study. Based on the concentrations of SO42-and NO3- in field water，this paper designed carbonic acid（0.033 mol?L-1 ）+ sulfuric acid + nitric acid（0.1-1.7 mmol?L-1）（CSN acid）and sulfuric acid + nitric acid（0.1-1.7 mmol?L-1）（SN acid）dissolution experiment on carbonate rocks，and the experiment lasted 144 hours. The results show that the dissolution rates of micrite and dolomite in the CSN acid are both higher than that in the SN acid.In the CSN acid，the dissolution rate of micrite is generally higher than that of dolomite， with average values of 1.34 mg·（cm2?d）-1 and 1.21 mg·（cm2?d）-1， respectively. In the SN acid，the dissolution rates of micrite and dolomite have little difference，and their average values are 0.92 mg·（cm2?d）-1 and 0.93 mg·（cm2?d）-1， respectively. The HCO3- concentration corresponds to the result of the dissolution rate. The average HCO3- values generated by dissolution of micrite and dolomite in the CSN acid solution are 1.43 mmol?L-1 and 1.33 mmol?L-1， while the average values of HCO3- generated by dissolution of micrite and dolomite in the SN acid are 0.33 mmol?L-1 and 0.39 mmol?L-1. The concentration of HCO3- in the CSN acid decreases with the increase of acid concentration，while the concentration in the SN acid increases with the increase of acid concentration. When the concentration of SO42- and NO3- is 0.1-0.3 mmol?L-1， the dissolution rate of carbonic acid to dolomite accounts for 75.89 %-58.64%， and the dissolution rate of carbonic acid to micrite accounts for 80.21%-59.06%.When the concentrations of SO42- and NO3- are more than 0.44 mmol?L-1，the dissolution rate of carbonate rock by carbonate acid will be less than 50%.When the concentrations of SO42- and NO3- are 0.0-0.2 mmol?L-1， the field measured data is basically consistent with the simulated data. However，when the concentration of SO42- and NO3- is higher than 0.2 mmol?L-1，the field measured data is higher than the simulated data. These results indicate that nitric acid and sulfuric acid significantly affect the dissolution of carbonate rock，which could provide references for the effects of other acids on karst carbon sink.
2021, 40(4): 617-624.
Abstract:
To further reveal the law of karst carbon cycle，as well as understand the characteristics and influencing factors of soil CO2 release in different land use types in the dolomites in the Huangzhouhe basin，which is the sub-basin of the Shanmuhe basin， a world natural heritage site in karst area， Shibing， southern China， in this study，the soil CO2 concentration in three different land use types （forest land， dryland， paddy field）were measured for one year.Soil samples were collected to analyze their physical and chemical properties. The results show that，（1） The annual average soil CO2 concentration in different land use types is， paddy field（21，008×10-6）> forest land（9，038×10-6）> dryland（5，660×10-6）；（2） The variation patterns of monthly soil CO2 concentration curve and monthly mean air temperature change curve of forestland and dryland in a year were similar，and annual variation law was generally consistent.The soil CO2 concentration gradually increased from January to July， and reached the peak value in August ，which was 16，157×10-6 and 13，458×10-6， respectively；（3） The CO2 concentration in paddy soil gradually decreased from January to March ， and the lowest value in March is 11，727×10-6， it gradually increased from March to December， and began to fluctuating increase in August， and reached a peak of 29，993×10-6 in October；（4） The soil CO2 concentration in dolomite area has a significant seasonal variation law of high in summer and autumn and low in spring；（5） Air temperature and rainfall have significant effects on CO2 concentration of forest land and dryland soil， but have no significant effect on the CO2 concentration of paddy field ；（6） The correlation coefficient of soil CO2 concentration corresponding to the difference of its organic carbon content is R=0.70 （P=0.03）， indicating that the difference of soil organic carbon has certain impacts on soil CO2 concentration， and the soil CO2 concentration increases with the increase of soil pH value.
To further reveal the law of karst carbon cycle，as well as understand the characteristics and influencing factors of soil CO2 release in different land use types in the dolomites in the Huangzhouhe basin，which is the sub-basin of the Shanmuhe basin， a world natural heritage site in karst area， Shibing， southern China， in this study，the soil CO2 concentration in three different land use types （forest land， dryland， paddy field）were measured for one year.Soil samples were collected to analyze their physical and chemical properties. The results show that，（1） The annual average soil CO2 concentration in different land use types is， paddy field（21，008×10-6）> forest land（9，038×10-6）> dryland（5，660×10-6）；（2） The variation patterns of monthly soil CO2 concentration curve and monthly mean air temperature change curve of forestland and dryland in a year were similar，and annual variation law was generally consistent.The soil CO2 concentration gradually increased from January to July， and reached the peak value in August ，which was 16，157×10-6 and 13，458×10-6， respectively；（3） The CO2 concentration in paddy soil gradually decreased from January to March ， and the lowest value in March is 11，727×10-6， it gradually increased from March to December， and began to fluctuating increase in August， and reached a peak of 29，993×10-6 in October；（4） The soil CO2 concentration in dolomite area has a significant seasonal variation law of high in summer and autumn and low in spring；（5） Air temperature and rainfall have significant effects on CO2 concentration of forest land and dryland soil， but have no significant effect on the CO2 concentration of paddy field ；（6） The correlation coefficient of soil CO2 concentration corresponding to the difference of its organic carbon content is R=0.70 （P=0.03）， indicating that the difference of soil organic carbon has certain impacts on soil CO2 concentration， and the soil CO2 concentration increases with the increase of soil pH value.
2021, 40(4): 625-635.
Abstract:
The response mechanism of karst carbon sink to climate change and land use patterns remains controversial. Dolomites with higher solubility than limestone may have higher karst carbon sink potential. However， most previous studies tend to calculate the karst carbon sink value of limestone and ignore the contribution of dolomite to karst carbon sink. Therefore， this paper selects the Huangzhouhe dolomite basin in Shibing county， Guizhou Province as the research object which has developed a typical dolomite karst landform and has become a world natural heritage protected area. We quantitatively estimate the annual average karst carbon sink strength of the dolomite basin in 1990-1992， 2001-2003 and 2016-2018 by using the dolomite chemical equilibrium thermodynamic method derived from the dolomite dissolution equilibrium equation， with a view to estimating the dolomite karst carbon sink value and its response mechanism to the joint effect of climate change and land use. The results show that，（1） The average annual rainfall in the basin decreases with time， but the effective rainfall in the second period is the largest due to the difference in evapotranspiration， followed by the first period， and the effective rainfall in the third period is the smallest；（2）The basin is mainly forested land. With the gradual increase of human activities， paddy fields， dry land， and construction land continue to increase， but the growth rate of the latter two types of land has slowed down， and due to the environmental regulations of the World Natural Heritage Site， the overall vegetation coverage of the basin shows a trend of restoration；（3）The overall karst carbon sink intensity in the basin at different periods of time is the second period， the first period， and the third period， and the corresponding karst carbon sink values are 31.68， 33.40，27.93 t CO2·km-2·a-1，respectively. Among different types of land use， although the carbon dioxide partial pressure of natural land is higher than that of land used for human activities，natural forest land with higher vegetation coverage causes greater water loss，making dry land and paddy fields affected by human activities significantly higher.The karst carbon sink value reached 31.97-32.64 t CO2·km-2·a-1， while the karst carbon sink value of forest land and shrubland was relatively small， only 28.64-30.48 t CO2·km-2·a-1.According to the above analysis， we believe that climate change and land use jointly act on karst carbon sink， and the rainfall runoff effect dominated by climate change obviously masks the carbon dioxide effect， and the intensity of karst carbon sink may not increase with the positive succession of land use. Moreover， by comparing the calculation results of karst carbon sink in limestone basins under the same climatic conditions， although different calculation methods and basin areas will lead to certain differences in karst carbon sink values， dolomite karst carbon sink still have a large karst carbon sink potential. Therefore， in the calculation of global terrestrial karst carbon sink， the role of global dolomite karst carbon sink should be taken seriously.
The response mechanism of karst carbon sink to climate change and land use patterns remains controversial. Dolomites with higher solubility than limestone may have higher karst carbon sink potential. However， most previous studies tend to calculate the karst carbon sink value of limestone and ignore the contribution of dolomite to karst carbon sink. Therefore， this paper selects the Huangzhouhe dolomite basin in Shibing county， Guizhou Province as the research object which has developed a typical dolomite karst landform and has become a world natural heritage protected area. We quantitatively estimate the annual average karst carbon sink strength of the dolomite basin in 1990-1992， 2001-2003 and 2016-2018 by using the dolomite chemical equilibrium thermodynamic method derived from the dolomite dissolution equilibrium equation， with a view to estimating the dolomite karst carbon sink value and its response mechanism to the joint effect of climate change and land use. The results show that，（1） The average annual rainfall in the basin decreases with time， but the effective rainfall in the second period is the largest due to the difference in evapotranspiration， followed by the first period， and the effective rainfall in the third period is the smallest；（2）The basin is mainly forested land. With the gradual increase of human activities， paddy fields， dry land， and construction land continue to increase， but the growth rate of the latter two types of land has slowed down， and due to the environmental regulations of the World Natural Heritage Site， the overall vegetation coverage of the basin shows a trend of restoration；（3）The overall karst carbon sink intensity in the basin at different periods of time is the second period， the first period， and the third period， and the corresponding karst carbon sink values are 31.68， 33.40，27.93 t CO2·km-2·a-1，respectively. Among different types of land use， although the carbon dioxide partial pressure of natural land is higher than that of land used for human activities，natural forest land with higher vegetation coverage causes greater water loss，making dry land and paddy fields affected by human activities significantly higher.The karst carbon sink value reached 31.97-32.64 t CO2·km-2·a-1， while the karst carbon sink value of forest land and shrubland was relatively small， only 28.64-30.48 t CO2·km-2·a-1.According to the above analysis， we believe that climate change and land use jointly act on karst carbon sink， and the rainfall runoff effect dominated by climate change obviously masks the carbon dioxide effect， and the intensity of karst carbon sink may not increase with the positive succession of land use. Moreover， by comparing the calculation results of karst carbon sink in limestone basins under the same climatic conditions， although different calculation methods and basin areas will lead to certain differences in karst carbon sink values， dolomite karst carbon sink still have a large karst carbon sink potential. Therefore， in the calculation of global terrestrial karst carbon sink， the role of global dolomite karst carbon sink should be taken seriously.
2021, 40(4): 636-643.
Abstract:
The analyses of the content of Dissolved Inorganic Carbon （DIC） in natural water and its stable carbon isotopic composition （δ13CDIC） provide an useful means for investigating the carbon cycle and its related biogeochemical processes. In recent years， the laser spectroscopic technology has provided us with a new method for isotopic analysis of DIC in water. In this study， we applied a TOC analyzer on-line with a laser Cavity Ring-Down Spectroscopy （CRDS） to determine DIC content and δ13CDIC value. The analytical precision and accuracy were discussed and both results determined by this system and the Isotopic Ratio Mass Spectrometer （IRMS） were compared. The results of the measurement of a large number of laboratory working standards and water samples with a wide range of DIC concentrations and δ13CDIC values show that such TOC-CRDS system has high analytical precisions. The relative standard deviation of DIC content test results are within 1%， and the precision of δ13CDIC is better than ±0.1‰ （1σ）. Measured δ13CDIC values by both TOC-CRDS and IRMS methods are close to each other， with a difference of mostly ≤0.3‰， an indicative of high accuracy for the TOC-CRDS system. Because the absorption spectrum is a function of gas concentration， however， the analytical precision and accuracy could be lowered for samples with lower CO2 yielding in the system. Thus， it is crucially important to make sure that the sample injected into the TOC analyzer has optimal carbon content. Moreover， it is better to use multiple working standards that have different δ13CDIC value to calibrate the measured values of water samples. Compared with the IRMS， the laser spectrometer is less costly and has advantages in fast， efficient determination of both DIC content and δ13CDIC value. In all， the machine is small and can be operated in the field， and it therefore has great potential to be one of useful methods in high-frequency monitoring of karst water， which benefits the study of karst dynamic system， karst critical zone processes and their responses to climatic and environmental changes.
The analyses of the content of Dissolved Inorganic Carbon （DIC） in natural water and its stable carbon isotopic composition （δ13CDIC） provide an useful means for investigating the carbon cycle and its related biogeochemical processes. In recent years， the laser spectroscopic technology has provided us with a new method for isotopic analysis of DIC in water. In this study， we applied a TOC analyzer on-line with a laser Cavity Ring-Down Spectroscopy （CRDS） to determine DIC content and δ13CDIC value. The analytical precision and accuracy were discussed and both results determined by this system and the Isotopic Ratio Mass Spectrometer （IRMS） were compared. The results of the measurement of a large number of laboratory working standards and water samples with a wide range of DIC concentrations and δ13CDIC values show that such TOC-CRDS system has high analytical precisions. The relative standard deviation of DIC content test results are within 1%， and the precision of δ13CDIC is better than ±0.1‰ （1σ）. Measured δ13CDIC values by both TOC-CRDS and IRMS methods are close to each other， with a difference of mostly ≤0.3‰， an indicative of high accuracy for the TOC-CRDS system. Because the absorption spectrum is a function of gas concentration， however， the analytical precision and accuracy could be lowered for samples with lower CO2 yielding in the system. Thus， it is crucially important to make sure that the sample injected into the TOC analyzer has optimal carbon content. Moreover， it is better to use multiple working standards that have different δ13CDIC value to calibrate the measured values of water samples. Compared with the IRMS， the laser spectrometer is less costly and has advantages in fast， efficient determination of both DIC content and δ13CDIC value. In all， the machine is small and can be operated in the field， and it therefore has great potential to be one of useful methods in high-frequency monitoring of karst water， which benefits the study of karst dynamic system， karst critical zone processes and their responses to climatic and environmental changes.
2021, 40(4): 644-653.
Abstract:
Karst faulted basin is an inter-mountainous basin formed by the differential subsidence and dissolution of fault blocks caused by the faulting activities of Cenozoic plateau uplifting.The visual identification marks include，（1） The basin forming area is characterized by continuous distribution of soluble rocks， staggered development of faults， and extensive distribution of dissolution landforms；（2） The shape is long-stripped or irregular；（3） The bottom plain covers an area of tens to hundreds of square kilometers. The Cenozoic deposits are thick and there are many underground rivers and springs exposed at the edge.The karst faulted basin is determined by the genetic mechanism of erosion and dissolution which is dominated by local faulted depression.The faulted basin is characterized by obvious geomorphic zoning， strong neotectonic movement， uneven distribution of water resources， strong zonation of soil and vegetation， obvious vertical climate change and large differences in human activities ranges.Marked by geomorphic form and genetic types，the karst faulted basin can be divided into four environmental geological zones： the erosion and dissolution mountain area， the dissolution hill ，peak and valley area， the sedimentary plain area， the erosion and dissolution valley area.The ecological function of the erosion and dissolution mountain area is prominent， the water source is mainly the seasonal stream running water， slope， roof and road sheet flow，and surface karst spring， suspended spring， surface karst zone water storage structure.The main water supply needs are domestic water for villages and towns， crop drought and seedling protection， production of small and micro enterprises and mines， ecological construction and maintenance. The ecological and economic functions are equally important in the area of the dissolution hill， peak and valley area. The water sources are mainly seasonal rivers and streams， sloping， roof and road sheet flow and stagnant water in depressions；as well as underground rivers， karst springs， surface karst zones and saturated water storage structures；water transfer from the outer basin.The main water supply needs are domestic water for villages and towns ， the water used in agricultural and sideline industry bases and individual retail drought and seedling protection， daily irrigation， breeding water， large-scale production of factories and mines， and ecological construction and maintenance.The economic function of the sedimentary plain area is particularly important， and the main water source is the perennial rivers and lake wetlands；underground river， karst spring， water storage structure in saturated water zone；water transfer from the other basins.The main water supply needs are water for urban， rural life and sanitation and other water， water for large-scale agricultural and sideline industry base and retail drought and seedling protection， daily irrigation， aquaculture water， industrial production and ecological construction and maintenance and other water.The function orientation of the erosion and dissolution valley area depends on the location and macroscopic influence of the big river basin. The main water sources of the erosion and dissolution valley area are mainly seasonal streams and perennial rivers， and the slope， roof and road patches sheet flow；underground river and karst spring， local surface zone and saturated zone water storage structure.The main water supply needs are domestic water for villages and towns ， crop drought resistance and seedling protection， industrial and mining， water conservancy， electric power enterprise production and ecological construction and maintenance and so on. Resource development and environmental restoration and protection should be coordinated with the environmental geology zoning function and resource characteristics， and the sustainable can be achieved only by basin system evaluation and scientific planning.The establishment of efficient utilization model of water resources in karst faulted basin is guided by the theory of sustainable development and system science， following the basic principle of hydrogeology， hydrology and water resources science， according to the water cycle law and resources and environment characteristics of karst faulted basin，through many means，such as system evaluation， multi-source water intake， optimization of regulation， and recycling ，so as to achieve high-efficiency utilization of surface and groundwater resources in karst faulted basin.The systematic engineering layout of efficient development and utilization of water resources in faulted basins is closely combined with the variation rules of basin resources and environmental zoning， according to the types of water source areas， water resources potential and water supply demand， water resources development technical conditions and vulnerability characteristics of different geological environment zoning.Along the formation， movement and conversion process of the surface and groundwater in the karst faulted basin， the water resources development and utilization projects are deployed step by step from the upstream mountainous area to the downstream valley area.In order to achieve efficient and sustainable development and utilization of water resources， we should take measures in accordance with local conditions in a scientific and reasonable manner， promote simultaneous development of large， medium， small and micro projects， give consideration to both centralized and decentralized water supply， and systematically promote water resources development and water quality restoration， water recycling and water conservation.System engineering and technical solutions for efficient utilization of water resources includes，（1）in the erosion and dissolution mountain area，small miniature reservoir with fountain， joint development project， regulation and storage project of water cellar， pool， pond water collection， local shallow well water engineering， etc.are mainly deployed in coorperation with small and micro water quality treatment， restoration， and recycling water-saving irrigation， soil moisture preservation technology systems.They jointly build a system project for efficient development and utilization of water resources to achieve multi-source intake， joint dispatch， and efficient utilization；（2）In the dissolution hill and peak valley area， large and medium-sized reservoir regulation and storage projects as well as small and medium-sized centralized water supply projects are mainly deployed，such as diversion and lifting of underground rivers and karst springs， diversion of water from deep wells， and the diversion of water from other basins ， supplemented by the rainwater collection projects of water cellars， pools and ponds， and the separate water supply projects of shallow wells.With the cooperation of small and micro water quality treatment， restoration， water-saving irrigation and soil moisture preservation technology system， the systematic project of highly efficient development and utilization of water resource are jointly constructed so as to realize the joint operation and efficient utilization of surface water and groundwater；（3）In sedimentary plain area，large and medium-sized centralized water supply projects are mainly deployed，such as large and medium-sized regulation and storage reservoir， underground river and karst spring diversion and well group water lifting.Sewage treatment plants and ecological wetland systems should be built to restore the quality of waste water， thus the water recycling system will be built in combination with the circulation of reservoirs in the middle and lower reaches of the basin to improve the utilization rate of water resources.The water-saving irrigation and soil moisture preservation systems should be promoted to impelment conservation and high-efficiency water use； （4）In the erosion and dissolution valley area，the diversion and development system of rivers， reservoirs and springs， rainwater collection projects of water cellars， pools and ponds， water storage projects of surface springs and suspended springs， and water carrying projects of local shallow wells are mainly deployed.Reservoirs and hydropower stations are built at the valley bottom to develop river and underground river energy resources. In cooperation with the technology system of small and micro water quality treatment， remediation and recycling， water-saving irrigation and soil moisture preservation， the efficient and comprehensive utilization of water resources will be achieved.The efficient utilization model of surface and groundwater resources in karst faulted basin condenses the results of predecessors studies and this research，which is the crystallization of basic research on water resources and environment， water resources investigation （survey） evaluation and development technology in karst faulted basin.It is the test of demonstration project that has proved its reality in accordance with karst faulted basin as well as scientific， reasonable and economic feasibility， which sets a universal model for the efficient development and utilization of water resources in karst faulted basin.
Karst faulted basin is an inter-mountainous basin formed by the differential subsidence and dissolution of fault blocks caused by the faulting activities of Cenozoic plateau uplifting.The visual identification marks include，（1） The basin forming area is characterized by continuous distribution of soluble rocks， staggered development of faults， and extensive distribution of dissolution landforms；（2） The shape is long-stripped or irregular；（3） The bottom plain covers an area of tens to hundreds of square kilometers. The Cenozoic deposits are thick and there are many underground rivers and springs exposed at the edge.The karst faulted basin is determined by the genetic mechanism of erosion and dissolution which is dominated by local faulted depression.The faulted basin is characterized by obvious geomorphic zoning， strong neotectonic movement， uneven distribution of water resources， strong zonation of soil and vegetation， obvious vertical climate change and large differences in human activities ranges.Marked by geomorphic form and genetic types，the karst faulted basin can be divided into four environmental geological zones： the erosion and dissolution mountain area， the dissolution hill ，peak and valley area， the sedimentary plain area， the erosion and dissolution valley area.The ecological function of the erosion and dissolution mountain area is prominent， the water source is mainly the seasonal stream running water， slope， roof and road sheet flow，and surface karst spring， suspended spring， surface karst zone water storage structure.The main water supply needs are domestic water for villages and towns， crop drought and seedling protection， production of small and micro enterprises and mines， ecological construction and maintenance. The ecological and economic functions are equally important in the area of the dissolution hill， peak and valley area. The water sources are mainly seasonal rivers and streams， sloping， roof and road sheet flow and stagnant water in depressions；as well as underground rivers， karst springs， surface karst zones and saturated water storage structures；water transfer from the outer basin.The main water supply needs are domestic water for villages and towns ， the water used in agricultural and sideline industry bases and individual retail drought and seedling protection， daily irrigation， breeding water， large-scale production of factories and mines， and ecological construction and maintenance.The economic function of the sedimentary plain area is particularly important， and the main water source is the perennial rivers and lake wetlands；underground river， karst spring， water storage structure in saturated water zone；water transfer from the other basins.The main water supply needs are water for urban， rural life and sanitation and other water， water for large-scale agricultural and sideline industry base and retail drought and seedling protection， daily irrigation， aquaculture water， industrial production and ecological construction and maintenance and other water.The function orientation of the erosion and dissolution valley area depends on the location and macroscopic influence of the big river basin. The main water sources of the erosion and dissolution valley area are mainly seasonal streams and perennial rivers， and the slope， roof and road patches sheet flow；underground river and karst spring， local surface zone and saturated zone water storage structure.The main water supply needs are domestic water for villages and towns ， crop drought resistance and seedling protection， industrial and mining， water conservancy， electric power enterprise production and ecological construction and maintenance and so on. Resource development and environmental restoration and protection should be coordinated with the environmental geology zoning function and resource characteristics， and the sustainable can be achieved only by basin system evaluation and scientific planning.The establishment of efficient utilization model of water resources in karst faulted basin is guided by the theory of sustainable development and system science， following the basic principle of hydrogeology， hydrology and water resources science， according to the water cycle law and resources and environment characteristics of karst faulted basin，through many means，such as system evaluation， multi-source water intake， optimization of regulation， and recycling ，so as to achieve high-efficiency utilization of surface and groundwater resources in karst faulted basin.The systematic engineering layout of efficient development and utilization of water resources in faulted basins is closely combined with the variation rules of basin resources and environmental zoning， according to the types of water source areas， water resources potential and water supply demand， water resources development technical conditions and vulnerability characteristics of different geological environment zoning.Along the formation， movement and conversion process of the surface and groundwater in the karst faulted basin， the water resources development and utilization projects are deployed step by step from the upstream mountainous area to the downstream valley area.In order to achieve efficient and sustainable development and utilization of water resources， we should take measures in accordance with local conditions in a scientific and reasonable manner， promote simultaneous development of large， medium， small and micro projects， give consideration to both centralized and decentralized water supply， and systematically promote water resources development and water quality restoration， water recycling and water conservation.System engineering and technical solutions for efficient utilization of water resources includes，（1）in the erosion and dissolution mountain area，small miniature reservoir with fountain， joint development project， regulation and storage project of water cellar， pool， pond water collection， local shallow well water engineering， etc.are mainly deployed in coorperation with small and micro water quality treatment， restoration， and recycling water-saving irrigation， soil moisture preservation technology systems.They jointly build a system project for efficient development and utilization of water resources to achieve multi-source intake， joint dispatch， and efficient utilization；（2）In the dissolution hill and peak valley area， large and medium-sized reservoir regulation and storage projects as well as small and medium-sized centralized water supply projects are mainly deployed，such as diversion and lifting of underground rivers and karst springs， diversion of water from deep wells， and the diversion of water from other basins ， supplemented by the rainwater collection projects of water cellars， pools and ponds， and the separate water supply projects of shallow wells.With the cooperation of small and micro water quality treatment， restoration， water-saving irrigation and soil moisture preservation technology system， the systematic project of highly efficient development and utilization of water resource are jointly constructed so as to realize the joint operation and efficient utilization of surface water and groundwater；（3）In sedimentary plain area，large and medium-sized centralized water supply projects are mainly deployed，such as large and medium-sized regulation and storage reservoir， underground river and karst spring diversion and well group water lifting.Sewage treatment plants and ecological wetland systems should be built to restore the quality of waste water， thus the water recycling system will be built in combination with the circulation of reservoirs in the middle and lower reaches of the basin to improve the utilization rate of water resources.The water-saving irrigation and soil moisture preservation systems should be promoted to impelment conservation and high-efficiency water use； （4）In the erosion and dissolution valley area，the diversion and development system of rivers， reservoirs and springs， rainwater collection projects of water cellars， pools and ponds， water storage projects of surface springs and suspended springs， and water carrying projects of local shallow wells are mainly deployed.Reservoirs and hydropower stations are built at the valley bottom to develop river and underground river energy resources. In cooperation with the technology system of small and micro water quality treatment， remediation and recycling， water-saving irrigation and soil moisture preservation， the efficient and comprehensive utilization of water resources will be achieved.The efficient utilization model of surface and groundwater resources in karst faulted basin condenses the results of predecessors studies and this research，which is the crystallization of basic research on water resources and environment， water resources investigation （survey） evaluation and development technology in karst faulted basin.It is the test of demonstration project that has proved its reality in accordance with karst faulted basin as well as scientific， reasonable and economic feasibility， which sets a universal model for the efficient development and utilization of water resources in karst faulted basin.
2021, 40(4): 654-660.
Abstract:
Jibi is located on the lower edge of Luxi basin，with poor uniformity of karst development，and serious surface drought and water shortage，so it is difficult to find water by drilling wells. In this paper，we discusses the hydrogeological conditions， and the distribution and occurrence characteristics of groundwater in Jibi area，and introduces the working method of groundwater prospecting and well layout in karst area. The well location is determined by using high density resistivity method，IP sounding ，combined with hydrogeological survey results，and the result shows the borehole has abundant water. The analysis shows that the difference of water abundance of karst aquifer is mainly controlled by the filling of karst fissures and the connectivity of karst aquifers. Finally， we summarizes and put forward a set of emergency drought relief models based on the development and utilization of karst water as the main leader，combining drought resistance with water-saving sprinkler and high efficiency agricultural development，with significant economic benefits. We also put forward the suggestion on management measures for prospecting and utilization of groundwater.
Jibi is located on the lower edge of Luxi basin，with poor uniformity of karst development，and serious surface drought and water shortage，so it is difficult to find water by drilling wells. In this paper，we discusses the hydrogeological conditions， and the distribution and occurrence characteristics of groundwater in Jibi area，and introduces the working method of groundwater prospecting and well layout in karst area. The well location is determined by using high density resistivity method，IP sounding ，combined with hydrogeological survey results，and the result shows the borehole has abundant water. The analysis shows that the difference of water abundance of karst aquifer is mainly controlled by the filling of karst fissures and the connectivity of karst aquifers. Finally， we summarizes and put forward a set of emergency drought relief models based on the development and utilization of karst water as the main leader，combining drought resistance with water-saving sprinkler and high efficiency agricultural development，with significant economic benefits. We also put forward the suggestion on management measures for prospecting and utilization of groundwater.
2021, 40(4): 661-670.
Abstract:
Huixian wetland is the largest karst wetland in China， which has important ecological and environmental functions. In recent years， the wetland has been shrinking and degrading significantly， and the ecological environment has gradually deteriorated. From the perspective of the hydrological process of wetland， based on the field fixed-point monitoring data， the seasonal water level distribution characteristics and its response to precipitation in Huixian Wetland were studied by statistical method. The conversion relationship between groundwater and surface water in wetland was analyzed， and the impact of fluctuation of wetland water level on ecological environment was further discussed. The results showed that the surface and groundwater levels of Huixian Wetland had significant spatial differences. Both of them responded rapidly to precipitation， and had significant multi-peak and multi-valley characteristics. The surface water level in the middle part of wetland was more stable than that in the marginal area， and the surface water areas in each area were connected with each other. The variation of groundwater level was affected by the topography， precipitation， karst development and Quaternary thickness， which showed similar characteristics to surface water， but the variation of water level gradually decreased from self-recharge to drainage area. Surface water and groundwater were closely related. Groundwater was an important recharge source for Huixian Wetland， which supplied surface water with a stable intensity all the year round. Pearson correlation analysis showed that there was a significant negative correlation between surface water level and water conductivity （R=-0.7808）. The increase of nutrient concentration during the decline of water level may induce eutrophication of water body. However， the correlation between groundwater level and shallow soil water content was not significant， and the disturbance to wetland habitat was small.
Huixian wetland is the largest karst wetland in China， which has important ecological and environmental functions. In recent years， the wetland has been shrinking and degrading significantly， and the ecological environment has gradually deteriorated. From the perspective of the hydrological process of wetland， based on the field fixed-point monitoring data， the seasonal water level distribution characteristics and its response to precipitation in Huixian Wetland were studied by statistical method. The conversion relationship between groundwater and surface water in wetland was analyzed， and the impact of fluctuation of wetland water level on ecological environment was further discussed. The results showed that the surface and groundwater levels of Huixian Wetland had significant spatial differences. Both of them responded rapidly to precipitation， and had significant multi-peak and multi-valley characteristics. The surface water level in the middle part of wetland was more stable than that in the marginal area， and the surface water areas in each area were connected with each other. The variation of groundwater level was affected by the topography， precipitation， karst development and Quaternary thickness， which showed similar characteristics to surface water， but the variation of water level gradually decreased from self-recharge to drainage area. Surface water and groundwater were closely related. Groundwater was an important recharge source for Huixian Wetland， which supplied surface water with a stable intensity all the year round. Pearson correlation analysis showed that there was a significant negative correlation between surface water level and water conductivity （R=-0.7808）. The increase of nutrient concentration during the decline of water level may induce eutrophication of water body. However， the correlation between groundwater level and shallow soil water content was not significant， and the disturbance to wetland habitat was small.
2021, 40(4): 671-679.
Abstract:
Guizhou Province is located in the mountainous area of southwest China， where the carbonate rocks are widely distributed. However， the uneven distribution of karst groundwater has brought great difficulties to the prospecting and development of karst groundwater， resulting in the lack of drinking water in some karst areas. In order to solve the problem of drinking water safety of rural people，the groundwater pumping well project in Wudang district of Guiyang City was carried out to study the karst water prospecting and development technology in karst peak cluster basin area，central Guizhou Province. Firstly， on the basis of the survey of topography， geological structure and hydrogeology in the area， the groundwater enrichment zones that may be laid out along the structure are delineated preliminarily. Secondly， the high density resistivity method was used to lay out geophysical profiles in the target area，and the trend and buried depth of the main runoff zone were identified according to the difference of electrical properties，so as to further determine the location of the well . Finally， through drilling construction and pumping test， the karst development degree and water abundance of aquifer in the area were fount out， and six wells were successfully constructed， which provided safe water source supply for local residents.The results show that karst peak cluster basin area in central Guizhou is an exposed karst area， and the main water-bearing rock groups are dolomite and calcite dolomite of Cambrian Loushanguan group， and the storage conditions of groundwater are poor. Karst is moderately developed in the area，the karst morphology is mainly dissolved fissures， local fissures， karst caves， faults and other water storage structural areas with strong water abundance，which is the groundwater enrichment area and is also the preferred location for the layout of pump well. This project has accumulated some experience for water prospecting and well drilling in similar karst water shortage area in southwest China.
Guizhou Province is located in the mountainous area of southwest China， where the carbonate rocks are widely distributed. However， the uneven distribution of karst groundwater has brought great difficulties to the prospecting and development of karst groundwater， resulting in the lack of drinking water in some karst areas. In order to solve the problem of drinking water safety of rural people，the groundwater pumping well project in Wudang district of Guiyang City was carried out to study the karst water prospecting and development technology in karst peak cluster basin area，central Guizhou Province. Firstly， on the basis of the survey of topography， geological structure and hydrogeology in the area， the groundwater enrichment zones that may be laid out along the structure are delineated preliminarily. Secondly， the high density resistivity method was used to lay out geophysical profiles in the target area，and the trend and buried depth of the main runoff zone were identified according to the difference of electrical properties，so as to further determine the location of the well . Finally， through drilling construction and pumping test， the karst development degree and water abundance of aquifer in the area were fount out， and six wells were successfully constructed， which provided safe water source supply for local residents.The results show that karst peak cluster basin area in central Guizhou is an exposed karst area， and the main water-bearing rock groups are dolomite and calcite dolomite of Cambrian Loushanguan group， and the storage conditions of groundwater are poor. Karst is moderately developed in the area，the karst morphology is mainly dissolved fissures， local fissures， karst caves， faults and other water storage structural areas with strong water abundance，which is the groundwater enrichment area and is also the preferred location for the layout of pump well. This project has accumulated some experience for water prospecting and well drilling in similar karst water shortage area in southwest China.
WU Dongqiang,
XING Liting,
LAN Xiaoxun,
MENG Qinghan,
HOU Yusong,
ZHAO Zhenhua,
SUN Bin,
YUAN Xuesheng
2021, 40(4): 680-688.
Abstract:
Jinan is a typical karst area in north China， with abundant karst water resources. The void structure of carbonate aquifers is the main seepage channel and storage space for karst water. The groundwater flowing in the pores continuously dissolves the carbonate rock， which intensifies the heterogeneity and complexity of the karst water-bearing medium. Through scholars’ research on the pore structure of carbonate rocks in north China，it is found that only by grasping of the pore structure characteristics of the karst water-bearing medium as well as understanding the movement laws of the karst water in the north China，can we provide a scientific basis for the sustainable utilization of karst groundwater. Taking Jinan spring area as an example， based on the atmospheric precipitation data groundwater level dynamic monitoring data and mercury intrusion porpsimetry test results of core in Jinan spring area from 2004 to 2019， the method of pore fractal dimension in fractal theory and mathematical statistics is used to explore the influence of pore structure of water-bearing rock formation on spring water level dynamics. The results show that， （1） The pores of the No.2 samples of the Chaomidian formation and Sanshanzi formation are well developed， the pore throats are concentrated， the rock formation has good water storage performance and large water storage space. The pores of the Bei’anzhuang section of the Majiagou formation are well-developed， with concentrated pore throats distribution，poor water storage performance and small water storage space. The No. 1 sample of the Sanshanzi formation and the Donghuangshan section of the Majiagou formation have uneven pore development， with scattered pore throat distribution， and large water storage space inside the rock； （2） The permeability of water-bearing stratum is affected by the distribution of pores and throats， pore surface roughness， pore heterogeneity， and the path and pore capillary bundles required for water flow seepage，of which the permeability of rock formation is mainly affected by the distribution of pores and throats； （3） There is a positive correlation between fractal dimension and groundwater dynamics.The fractal dimension of Chaomidian formation in the drainage area is smaller than that of Bei’anzhuang section. The annual variation of the groundwater level of the Chaomidian formation in the drainage area is smaller than that of the Bei’anzhuang section. The carbonate aquifer in Jinan spring area has large pore water storage space and good water storage performance. The unique pore structure of Jinan spring area plays an important role in maintaining the dynamic stability of Baotu spring water level.
Jinan is a typical karst area in north China， with abundant karst water resources. The void structure of carbonate aquifers is the main seepage channel and storage space for karst water. The groundwater flowing in the pores continuously dissolves the carbonate rock， which intensifies the heterogeneity and complexity of the karst water-bearing medium. Through scholars’ research on the pore structure of carbonate rocks in north China，it is found that only by grasping of the pore structure characteristics of the karst water-bearing medium as well as understanding the movement laws of the karst water in the north China，can we provide a scientific basis for the sustainable utilization of karst groundwater. Taking Jinan spring area as an example， based on the atmospheric precipitation data groundwater level dynamic monitoring data and mercury intrusion porpsimetry test results of core in Jinan spring area from 2004 to 2019， the method of pore fractal dimension in fractal theory and mathematical statistics is used to explore the influence of pore structure of water-bearing rock formation on spring water level dynamics. The results show that， （1） The pores of the No.2 samples of the Chaomidian formation and Sanshanzi formation are well developed， the pore throats are concentrated， the rock formation has good water storage performance and large water storage space. The pores of the Bei’anzhuang section of the Majiagou formation are well-developed， with concentrated pore throats distribution，poor water storage performance and small water storage space. The No. 1 sample of the Sanshanzi formation and the Donghuangshan section of the Majiagou formation have uneven pore development， with scattered pore throat distribution， and large water storage space inside the rock； （2） The permeability of water-bearing stratum is affected by the distribution of pores and throats， pore surface roughness， pore heterogeneity， and the path and pore capillary bundles required for water flow seepage，of which the permeability of rock formation is mainly affected by the distribution of pores and throats； （3） There is a positive correlation between fractal dimension and groundwater dynamics.The fractal dimension of Chaomidian formation in the drainage area is smaller than that of Bei’anzhuang section. The annual variation of the groundwater level of the Chaomidian formation in the drainage area is smaller than that of the Bei’anzhuang section. The carbonate aquifer in Jinan spring area has large pore water storage space and good water storage performance. The unique pore structure of Jinan spring area plays an important role in maintaining the dynamic stability of Baotu spring water level.
2021, 40(4): 689-697.
Abstract:
Karst springs in Jinan City are the main water supply source，thus，it is of great significance to find out the dynamic law of spring water and reasonably and scientifically forecast the spring water level for the development，utilization and protection of karst water resources. In this paper，firstly，the daily water level data of Baotu Spring and Heihu Spring from May 2，2012 to October 31，2018 are decomposed into trend terms，periodic terms and random terms by applying with time series analysis method， the dynamic variation law of spring water level was analyzed and the water level forecast model was established. The results show that there is no obvious trend change of spring water level dynamics at this stage，however， under the influence of precipitation，there are two major periods of dynamic variation of spring water level ，perennial change（3.2 years）and seasonal change. At the same time，due to the influence of various irregular interference factors，the dynamic variation of spring water level presents a random term. Secondly，the prediction accuracy of the forecast model is verified by the daily spring water level data from November 1，2018 to August 24，2020，and the results show that the model runs reasonably and has good prediction effect， with certain practical value. Finally，the spring water level（ from August 25，2020 to October 31，2022） is forecasted by above model，which provides a basis for the development and management of local karst water resources.
Karst springs in Jinan City are the main water supply source，thus，it is of great significance to find out the dynamic law of spring water and reasonably and scientifically forecast the spring water level for the development，utilization and protection of karst water resources. In this paper，firstly，the daily water level data of Baotu Spring and Heihu Spring from May 2，2012 to October 31，2018 are decomposed into trend terms，periodic terms and random terms by applying with time series analysis method， the dynamic variation law of spring water level was analyzed and the water level forecast model was established. The results show that there is no obvious trend change of spring water level dynamics at this stage，however， under the influence of precipitation，there are two major periods of dynamic variation of spring water level ，perennial change（3.2 years）and seasonal change. At the same time，due to the influence of various irregular interference factors，the dynamic variation of spring water level presents a random term. Secondly，the prediction accuracy of the forecast model is verified by the daily spring water level data from November 1，2018 to August 24，2020，and the results show that the model runs reasonably and has good prediction effect， with certain practical value. Finally，the spring water level（ from August 25，2020 to October 31，2022） is forecasted by above model，which provides a basis for the development and management of local karst water resources.
2021, 40(4): 698-706.
Abstract:
Systematic clarifying the evolution trend of karst rocky desertification is of great significance to correctly understand the occurrence and development process of karst rocky desertification and implement effective comprehensive control measures of rocky desertification. The results shows that， （1） There are 4 main factors driving the occurrence and formation of rocky desertification，such as single livelihood of farmers in karst mountainous areas， high land pressure， low land carrying capacity and fragile ecology. The essence of the occurrence and expansion of karst rocky desertification is that under the background of low land carrying capacity， land use patterns such as over-cutting， over-cultivation and over-grazing triggered land degradation in karst mountainous areas， that is， rocky desertification. （2） After karst rocky desertification occurs and develops to a certain stage， with the evolution of social and economic background and the change and disappearance of rocky desertification driving factors， the trend of rocky desertification area expansion will undergo a fundamental turning point， namely，the transformation of rocky desertification. （3） The change of land use pattern in karst mountainous areas in southwest China leads to the change of ecosystem mechanism， which leads to the transformation and evolution of rocky desertification. Rocky desertification transformation is the response of land use system to the comprehensive action of economic and social development and ecosystem， which is in line with the general trend of economic and social development and ecosystem evolution. （4） The transformation and evolution of rocky desertification in karst mountainous areas in southwest China has a guiding significance for revealing the change of man-land relationship in karst mountainous areas of southwest China.
Systematic clarifying the evolution trend of karst rocky desertification is of great significance to correctly understand the occurrence and development process of karst rocky desertification and implement effective comprehensive control measures of rocky desertification. The results shows that， （1） There are 4 main factors driving the occurrence and formation of rocky desertification，such as single livelihood of farmers in karst mountainous areas， high land pressure， low land carrying capacity and fragile ecology. The essence of the occurrence and expansion of karst rocky desertification is that under the background of low land carrying capacity， land use patterns such as over-cutting， over-cultivation and over-grazing triggered land degradation in karst mountainous areas， that is， rocky desertification. （2） After karst rocky desertification occurs and develops to a certain stage， with the evolution of social and economic background and the change and disappearance of rocky desertification driving factors， the trend of rocky desertification area expansion will undergo a fundamental turning point， namely，the transformation of rocky desertification. （3） The change of land use pattern in karst mountainous areas in southwest China leads to the change of ecosystem mechanism， which leads to the transformation and evolution of rocky desertification. Rocky desertification transformation is the response of land use system to the comprehensive action of economic and social development and ecosystem， which is in line with the general trend of economic and social development and ecosystem evolution. （4） The transformation and evolution of rocky desertification in karst mountainous areas in southwest China has a guiding significance for revealing the change of man-land relationship in karst mountainous areas of southwest China.
2021, 40(4): 707-717.
Abstract:
Karst rocky desertification has brought a series of ecological environment and socioeconomic problems to regional development. Since the implementation of ecological control projects， regional karst rocky desertification has been improved to a certain extent. In order to explore the changes of karst rocky desertification pattern after the implementation of ecological control project，Guangnan county，a typical karst area in southeastern of Yunnan，was taken as an example in this study. Based on three remote sensing images of 2000，2010 and 2018 as the data source，the spatial distribution data of karst rocky desertification was obtained through human-computer interactive interpretation，and the methods of time variation，transfer matrix，and superposition analysis were used to analyze the spaial-temporal pattern evolution characteristics of karst rocky desertification in Guangnan County. Characteristics of the evolution of the spatial and temporal pattern of desertification. The results show that，（1）Temporally，the type of karst rocky desertification in Guangnan county is still dominated by severe karst rocky desertification，but the area of karst rocky desertification is generally decreasing. Shrub land and unutilized land have the largest karst rocky desertification area.Shrub land is dominated by potential karst rocky desertification，while unutilized land is dominated by severe karst rocky desertification，both of them are the key land use types for the implementation of karst rocky desertification control projects. From 2000 to 2010，the transfer direction of karst rocky desertification is to non-karst rocky desertification and adjacent grade rocky desertification，while，from 2010 to 2018，the transfer direction of karst rocky desertification is to low grade rocky desertification；（2）Spatially ，the karst rocky desertification area in Guangnan county is more in the north and less in the south，showing a distribution pattern of karst desertification of heavy in the south and light in the north.The karst rocky desertification is concentrated along the Zhuanjiao township-Heizhiguo township-south of Nanping town-the southwestern part of Babao town，the adjacent area of Zhulin town and Wuzhu township，Zhujie town and Shuguang township；（3）During the past 19 years，the karst rocky desertification in the southern area of Guangnan county has been improved greatly，while the karst rocky desertification in the central and northern regions continued to deteriorate. On the whole，the implementation of ecological control projects such as Grain for Green project can effectively improve the karst rocky desertification situation in the karst area and reduce the total area of karst rocky desertification in Guangnan county by 288.98 km2.
Karst rocky desertification has brought a series of ecological environment and socioeconomic problems to regional development. Since the implementation of ecological control projects， regional karst rocky desertification has been improved to a certain extent. In order to explore the changes of karst rocky desertification pattern after the implementation of ecological control project，Guangnan county，a typical karst area in southeastern of Yunnan，was taken as an example in this study. Based on three remote sensing images of 2000，2010 and 2018 as the data source，the spatial distribution data of karst rocky desertification was obtained through human-computer interactive interpretation，and the methods of time variation，transfer matrix，and superposition analysis were used to analyze the spaial-temporal pattern evolution characteristics of karst rocky desertification in Guangnan County. Characteristics of the evolution of the spatial and temporal pattern of desertification. The results show that，（1）Temporally，the type of karst rocky desertification in Guangnan county is still dominated by severe karst rocky desertification，but the area of karst rocky desertification is generally decreasing. Shrub land and unutilized land have the largest karst rocky desertification area.Shrub land is dominated by potential karst rocky desertification，while unutilized land is dominated by severe karst rocky desertification，both of them are the key land use types for the implementation of karst rocky desertification control projects. From 2000 to 2010，the transfer direction of karst rocky desertification is to non-karst rocky desertification and adjacent grade rocky desertification，while，from 2010 to 2018，the transfer direction of karst rocky desertification is to low grade rocky desertification；（2）Spatially ，the karst rocky desertification area in Guangnan county is more in the north and less in the south，showing a distribution pattern of karst desertification of heavy in the south and light in the north.The karst rocky desertification is concentrated along the Zhuanjiao township-Heizhiguo township-south of Nanping town-the southwestern part of Babao town，the adjacent area of Zhulin town and Wuzhu township，Zhujie town and Shuguang township；（3）During the past 19 years，the karst rocky desertification in the southern area of Guangnan county has been improved greatly，while the karst rocky desertification in the central and northern regions continued to deteriorate. On the whole，the implementation of ecological control projects such as Grain for Green project can effectively improve the karst rocky desertification situation in the karst area and reduce the total area of karst rocky desertification in Guangnan county by 288.98 km2.
2021, 40(4): 718-727.
Abstract:
In this paper， Guizhou Province，the most serious rocky desertification area in China and a typical example of karst landform in southwest China，was taken as the research area.By investgating the country area of rocky desertification control in Guizhou，this paper explores the manifestations and causes of county-level conflicts in the countries of rocky desertification control， so as to put forward corresponding optimization measures and improve the governance effect. Collecting and sorting out the situation of rocky desertification control in Guizhou through the written materials， statistical data and other documents； Obtaining information by talking with the personnel of the county administrative department and the beneficiary people. Going to the rocky desertification control area for on-the-spot observation， collecting data based on intuitive impression and experience， and having statistical analysis of all data. There are great differences in the effectiveness of rocky desertification control among different counties in Guizhou Province. This difference is not only restricted by the spatial contradiction between the administrative regions and the governance regions caused by the natural geographical factors in karst area， but also comes from the differences in governance idea， administrative capacity， the input variance of resource elements among different counties. There are three forms of county-level conflicts in rocky desertification control， the first is the spatial contradiction between the administrative regions and the administrative regions，the second is the conflict between different counties in the same drainage area，the third is to form the neglected "marginal governance area" in the border zone of different counties. Therefore， it is suggested to jointly promote the future rocky desertification control from the two aspects， the optimization of natural space and the improvement of administrative.
In this paper， Guizhou Province，the most serious rocky desertification area in China and a typical example of karst landform in southwest China，was taken as the research area.By investgating the country area of rocky desertification control in Guizhou，this paper explores the manifestations and causes of county-level conflicts in the countries of rocky desertification control， so as to put forward corresponding optimization measures and improve the governance effect. Collecting and sorting out the situation of rocky desertification control in Guizhou through the written materials， statistical data and other documents； Obtaining information by talking with the personnel of the county administrative department and the beneficiary people. Going to the rocky desertification control area for on-the-spot observation， collecting data based on intuitive impression and experience， and having statistical analysis of all data. There are great differences in the effectiveness of rocky desertification control among different counties in Guizhou Province. This difference is not only restricted by the spatial contradiction between the administrative regions and the governance regions caused by the natural geographical factors in karst area， but also comes from the differences in governance idea， administrative capacity， the input variance of resource elements among different counties. There are three forms of county-level conflicts in rocky desertification control， the first is the spatial contradiction between the administrative regions and the administrative regions，the second is the conflict between different counties in the same drainage area，the third is to form the neglected "marginal governance area" in the border zone of different counties. Therefore， it is suggested to jointly promote the future rocky desertification control from the two aspects， the optimization of natural space and the improvement of administrative.
2021, 40(4): 728-738.
Abstract:
The Karst Rocky Desertification（KRD）encroaches the regional land resources and limits the sustainable development，which has received extensive attention from scholars and governments at home and abroad. Considering the long-term and arduous nature of the prevention and control of KRD，it is benefical to support the control and restoration of KRD by sorting out the relevant international progress on KRD and analyzing the research trend and frontier hotspot of KRD. Based on the database of Web of Science TM Core Collection，this study retrieved and collected the internationally published references of KRD research. The CiteSpace，a reference analysis tool，was used to visual express and analyze the KRD research. Results showed that，（1） Comparing the global carbonate rock and population distribution ，it is found that the carbonate rock outcrops are widely distributed in the world and the KRD was found in various countries. However，the intense human disturbance has resulted in the serious KRD in the southwest China；（2） China is in the leading position in the scentific studies of KRD and has the largest volume of publications in the world.The number of publication has undergone a development process of early development-slow growth-steady growth-rapid growth ，which is closely related to the research of Chinese scholars and government investment； （3）The southwest part of China，typically represented by Guizhou Province，is the core research region for publications. The monitoring and control of KRD and its ecological and environmental impacts are current hotspot and difficulties . This paper reviewed the effects of karst natural environment and human activities and their interactions on the succession of KRD， as well as clarified the ecological and environmental effects caused by the progressive succession and retrogressive sucession of KRD. Based on the published papers，three future aspects were suggested to be deeply studied： high-precision automatic mapping technology of KRD，mutual feedback mechanism between KRD and human activities，synergy path between KRD restoration and eco-environment improvement.
The Karst Rocky Desertification（KRD）encroaches the regional land resources and limits the sustainable development，which has received extensive attention from scholars and governments at home and abroad. Considering the long-term and arduous nature of the prevention and control of KRD，it is benefical to support the control and restoration of KRD by sorting out the relevant international progress on KRD and analyzing the research trend and frontier hotspot of KRD. Based on the database of Web of Science TM Core Collection，this study retrieved and collected the internationally published references of KRD research. The CiteSpace，a reference analysis tool，was used to visual express and analyze the KRD research. Results showed that，（1） Comparing the global carbonate rock and population distribution ，it is found that the carbonate rock outcrops are widely distributed in the world and the KRD was found in various countries. However，the intense human disturbance has resulted in the serious KRD in the southwest China；（2） China is in the leading position in the scentific studies of KRD and has the largest volume of publications in the world.The number of publication has undergone a development process of early development-slow growth-steady growth-rapid growth ，which is closely related to the research of Chinese scholars and government investment； （3）The southwest part of China，typically represented by Guizhou Province，is the core research region for publications. The monitoring and control of KRD and its ecological and environmental impacts are current hotspot and difficulties . This paper reviewed the effects of karst natural environment and human activities and their interactions on the succession of KRD， as well as clarified the ecological and environmental effects caused by the progressive succession and retrogressive sucession of KRD. Based on the published papers，three future aspects were suggested to be deeply studied： high-precision automatic mapping technology of KRD，mutual feedback mechanism between KRD and human activities，synergy path between KRD restoration and eco-environment improvement.
Founded in 1982 bimonthly
ISSN: 1001-4810
CN 45-1157/P
Editor-in-chief: Jiang Zhongcheng
Sponsor: Chinese Academy of Geological Sciences
Sponsored by: Institute of Karst Geology, Chinese Academy of Geological Sciences
Cosponsor: International Research Center on Karst under the Auspices of UNESCOKarst Geology Committee of Geological Society of ChinaSpeleology Committee of Geological Society of China
Wechat
