地下河系统水土资源关系

Relationship Between Land Resources and Water Resouces in Underground River System

中国南方地下河分布广泛,仅湘、川(渝)、黔、桂、滇、鄂等地就有流量>50L/s的地下河2444条。每一条地下河都构成一个相对独立的系统。因此,运用系统科学的方法开发利用地下河系统是解决南方岩溶区水土资源利用中长期存在的不合理现象的关键。初步分析了地下河系统的水土资源基本特征。山地多,耕地少,山高坡陡,土壤瘠薄,利用方式原始粗糙。降雨在不同的地下河系统中具有显著的时空不均一性,在同一系统的不同部位也存在着差异;地下河对暴雨响应灵敏。在此基础上探讨了地下河系统水土资源的基本格局以及相互关系。地下河系统具有独特的的水土分离格局,即"土在楼上,水在楼下"。土地资源的不同利用常常造成地下河的农药、化肥和细菌污染,引发雨后旱情。而地下河系统特殊的水资源特征叠加不适当的土地利用方式,加剧土地资源质的降低和量的流失,及土地资源的淹没。现状和成功的事例表明,地下河系统水土资源应该并且是可以合理利用而达到水、土、林、人的协调发展的。

Underground rivers mainly distribute in South China with total numbers of 2 444 more than 50 L/s only in Hunan, Sichuan, Guizhou, Yunnan, Hubei provinces and Guangxi Zhuang Nationality Autonomous region. Each Underground river constitutes a system consisting of surface peakcluster depression/valley subsystem, or hill depression/valley subsystem and subterranean conduit subsystem. It discusses basic characteristics of water and land resources in underground river system, which are much mountain, less arable land with thin and poor soil simply and primarily used by human, and uneven temporal and spatial distribution of precipitation in the different systems and different places of the same system, and quick response of subterranean rivers to precipitation etc. After that, basic pattern and relationship between land and water resources are discussed. This pattern is that water is under the surface, land is on the surface. So, unfit usage of land resources often causes the pollution of underground river by pesticides, fertilizers and bacteria and prevalence of dry hazard after rain season. The characteristics of water resources with unfit use of land resources in underground river system amplifies the decrease in qualification the erosion in amount of land resources and waterlogging hazard. The situation and successful examples of exploited underground river systems show that water and land resources should and can be adequately used in order to realize the equilibrium among water resources, land resources, forestry and human development.