Abstract:

There are some environmental problems such as drought,soil erosion,and ecoenvironmental degradation caused by the special geological conditions in the karst region of Luota,west of Hunan.13 demonstration projects of karst water resources exploitation were performed on the basis of analysis and investigation on natural environment,water and soil resources and ecoenvironment in Luota.Then,techniques and methods to successfully construct synthesized utilization modes of karst water were summarized systematically taking the subterranean river system as a unit.They are as follows: ①the mode of blocking up caves and leaving water from subterranean stream,namely,leaving water and generating electricity by damming in subterranean river； ②the mode of leaving water from large spring or the outlet of subterranean river; ③the mode of leaving water from subterranean river by digging tunnels,namely,damming subterranean river and raising water table in order to irrigate and generate electricity by digging tunnels; ④the mode of building surfaceground reservoir in karst depression and valley; ⑤the mode of exploiting epikarst spring by constructing water tank.The surface and underground karst developed considerably in the areas of peakcluste depression,which have closely hydraulic affiliation because of mutual linkage into a karst spatial system.By thorough investigation on karst system,it was proposed that the sufficient utilization on the spatial coalition of the karst depression at surface and underground cavities into reservoir is one of the principal ways to take advantage of karst ground water.The results showed that the flood can be effectively intercepted and restored in the karst area of southwast China by the couplingmanagement of the underground karst reservoir and the surface reservoir,which can cause the increase of the exploitation of ground water and improve the environmental quality of ground water and surface water.All these provided feasible techniques and references for implement of sustainable development strategy of water,land and ecology,the development of ecological economy,and the benign circulation between social economy and ecoenvironment,and was of important realistic significance for sustainable development of social economy in west Hunan.

Key words: karst water resources, exploitation and utilization mode, the karst region of Luota, hydrogeological factors