Analysis on karst groundwater system and its water resources composition in Shiqihe basin

Based on the further study on the aquifer structure characteristics and water resources formation of the karst groundwater system in Shiqihe basin, the flow attenuation process after the last flood peak in 2005(the biggest flood in the year) was taken as the data source to establish a total discharge-flow attenuation equation through the series analysis on the long-term observation data of the dynamic flow at the total discharge site. And then, the water resources composition was studied and analysis by means of the attenuation equation in the paper. The results show that total natural karst water discharge of the Shiqi river is 69 469.95×104 m3during the largest flood peak in 2005, which is composed of 4 parts: Slope runoff accounts for 3.64%, large scale karst conduit flow accounts for 4.53%, small karst conduit flow or strong developed karst fissure flow accounts for 74.10%, and small karst fissure flow accounts for 17.73 %. From the initial attenuation (can be regarded as the effective karst water resources), those flow can last for 2, 8 and 35 as well as more than 126 days respectively.