Characteristics of water loss and soil erosion and some scientific problems on karst rocky desertification in Southwest China karst area
-
摘要: 由于特殊的岩土组构,喀斯特坡地的水土流失具有如下特点:地表和地下流失相互叠加;地表产流、产沙少;纯碳酸盐岩区地下流失比例大。论文区别了石漠化和石质化的科学内涵,指出了喀斯特山地石漠化的核心是土地的石质化,提出了按照地面物质组成与裸岩率叠加的石漠化分类系统。根据土壤中硅酸盐矿物的物质平衡,提出了不同碎屑岩含量碳酸盐岩区的土壤允许流失量介于5~500 t/(km2?a)之间。喀斯特坡地土壤虽然肥沃,但总量太少,矿质养分不足可能是石质坡地植物生产力低的重要原因。此外,根据农耕驱动土地石质化的机制,提出了相应的石漠化治理的对策建议,具体是:(1)不但要治标,提高植被覆盖率,更要治本,防止或减缓土地石质化,同时还要增加群众收入;(2)按照坡地岩土组成的垂直分带特点,因地(土)制宜,开展治理;(3)重视矿质肥料的施用;(4)在纯碳酸盐岩土石质和石质坡地农田的小型蓄水工程修建中,要加强集流面建设。Abstract: Because of specific rock and soil composition and texture in the karst superficial zone, water loss and soil erosion on slopes in karst area is of the following characteristics: (1) superimposition of soil loss on the ground surface and under the ground; (2) limited ground surface runoff and sediment yields; and (3) higher sediment contribution from underground soil loss. This paper distinguishes scientific concept of karst land desertification and karst land rockification, points out that the rockification being the core of karst land desertification, and proposes a superimposed classification system for karst land desertification. The soil loss tolerances are mainly controlled by the proportion of clastic rocks and range between 5t/(km2.a) and 500(t/km2.a), which are derived from silicate mineral budgets in soils. The soils are fertile, but the land is poor because of limited soil body amount on rocky slopes; and the low plant productivities are probably caused by the shortage of mineral nutrient supply. According to the mechanism of karst land rockification being driven by the stress of cultivation, following countermeasures against karst land desertification are suggested: (1) not only improving vegetation to cure the symptoms , but also preventing or mitigating land rockification to cure the basic cause and increasing farmers’ incomes; (2)countermeasures against karst land desertification should be suit to the vertical zoning conditions of rock and soil compositions in karst mountains; (3) paying more attention to application of mineral fertilizers; and (4) using the surfaces of field roads and paths as water harvesting catchments to collect runoff for micro water storage tanks on cultivated rocky or stony land.
-
Key words:
- karst /
- water loss and soil erosion /
- rocky desertification /
- preventive treatment /
- Southwest China
-
[1] 张信宝, 王世杰, 贺秀斌, 等. 西南岩溶山地坡地石漠化分类刍议[J ]. 地球与环境, 2007, 35 (2) : 188- 192. [2] 张信宝,王世杰,贺秀斌,等.碳酸盐岩风化壳中的土壤蠕滑与岩溶坡地的土壤地下漏失[J].地球与环境,2007,35(3):202-206. [3] 张信宝, 王世杰, 曹建华.西南喀斯特山地的土壤流失与土壤的硅酸盐矿物质平衡[J].地球与环境,2009,37(2):97-102. [4] 张信宝 ,王克林. 西南碳酸盐岩石质山地土壤植被系统中矿质养分不足问题的思考[J].地球与环境,2009,37(4): 337-206. [5] 张信宝, 王世杰, 孟天友.农耕驱动西南喀斯特地区坡地石质化的机制[J]. 地球与环境,2010,38(2):123-128. [6] 柴宗新.试论广西岩溶区的土壤侵蚀[J].山地研究,1989,7(4):255-260. [7] 韦启璠.我国南方喀斯特区土壤侵蚀特点及防止途径[J].水土保持研究.1996,3(4):72-76. [8] 李阳兵,王世杰,魏朝富,等.贵州省碳酸盐岩地区土壤允许流失量的空间分布[J].地球与环境,2006,34(4):36-40. [9] 曹建华,蒋忠诚,杨德生,等.我国西南岩溶区土壤侵蚀强度分级标准研究[J].中国水土保持科学,2008,6(6):1-7. [10] 严冬春,文安邦,鲍玉海,等. 黔中岩溶坡地的土壤与137Cs的分布[J].地球与环境,2008,36(4),342-346. [11] 李豪 ,张信宝 ,王克林,等.桂西北倒石堆型岩溶坡地土壤的137Cs 分布特点[J].水土保持学报,2009, 23(3),42-47. [12] 彭韬,王世杰,张信宝,等.喀斯特坡地地表径流系数监测初报[J].地球与环境,2008,2(36):152-157. [13] 彭韬,杨涛,王世杰,等.喀斯特坡地土壤流失监测结果简报[J].地球与环境,2009,(37)2:126-130. [14] 何永彬 ,李 豪 ,张信宝,等.贵州茂兰峰丛森林洼地泥沙堆积速率的137Cs 示踪研究[J]. 地球与环境,2009, (37)4:366-371. [15] Xinbao Zhang,Xiaoyong Bai and Anbang Wen,A preliminary investigation of the potential for using the 137Cs technique to date sediment deposits in karst depressions and estimate rates of soil loss karst catchments in Southwest China[M]. IAHS publication (in press) [16] 何永彬 ,李 豪 ,张信宝,等.贵州茂兰峰丛草地洼地小流域侵蚀产沙的137Cs 法研究,中国岩溶,2009,28(2):181-188. [17] ZHANG Xinbao , BAI Xiaoyong , LIU Xiuming, Application of 137Cs fingerprinting technique to interpreting responces of sediment deposition of a karst depression to deforestation in the catchment of the Guizhou Plateau, China[M]. (in press) [18] 白晓永,张信宝 ,王世杰,等.普定冲头峰丛洼地泥沙沉积速率的137Cs法测定[J].地球与环境,2009, (37)2: 142-146. [19] Xiubin He ,Xiaoyong Bai ,Xinbao Zhang and Xiuming,LIU, Use of depression deposits and Caesium-137 measurements to investigate the erosional response to recent deforestation in a small catchment in the Guizhou karst Plateau region of Southwest China[M]. (in press) [20] 白晓永,王世杰,陈起伟,等. 贵州土地石漠化类型时空演变过程及其评价[J].地理学报,2009,64(5):609-618 [21] Xiaoyong Bai,Xinbao Zhang, Hu Chen and Yongbing He. Using Cs-137 fingerprint techenique to estimate sediment deposition and erosion rates from Yongkang depression in karst region of Southwest China[J]. Land Degradation & Development.2010, 21:1-6. -
点击查看大图
计量
- 文章访问数: 2153
- HTML浏览量: 451
- PDF下载量: 2421
- 被引次数: 0
下载: