南方小型岩溶流域与非岩溶流域的释水过程及径流组分差异

我国南方岩溶流域和非岩溶流域下垫面条件和含水介质结构的差异造成了不同的产汇流过程及机制，进而导致不同释水时段径流组分的开发利用价值不同。为深入理解岩溶流域的产汇流机制并探索岩溶流域的水资源评价方法，文章对鄂西庙沟岩溶流域和高家坪非岩溶流域共31次洪水过程进行了流量衰减分析，对比分析了两个流域的标准衰减方程、典型次降雨的释水过程以及不同洪峰流量下的径流组分差异。结果表明:岩溶流域的释水过程快于非岩溶流域，其衰减系数比非岩溶流域大40％；两个流域的河流基流均来自裂隙介质释水，裂隙介质为流域的主要储水空间，但非岩溶流域的裂隙介质比例比岩溶流域高8.8％；随洪峰流量增加，两个流域的地表径流占比均呈对数形式增大，地下径流占比均呈对数形式减小；岩溶流域径流组分随洪峰流量变化比非岩溶流域更为敏感，其地表径流占比变幅为4％~40％，而非岩溶流域则始终小于10％。文章定量评价了管道和裂隙介质在流域中的导水及储水功能，在进一步刻画岩溶流域产汇流过程及机制方面进行了有益的探索，研究结果可为岩溶山区水资源评价和流域水文模型的改进提供科学依据。

Variations in discharge processes and runoff components between small karst watersheds and non-karst watersheds in Southern China

The differences in the underlying surface conditions and the structure of aquifers in karst watersheds and non-karst watersheds in southern China lead to different runoff generation, which results in different development and utilization values of runoff components in different water discharge processes. In order to understand the runoff generation of karst watersheds and explore the water resources evaluation methods in karst watersheds, 31 flooding events in the Miaogou karst watershed and the Gaojiaping non-karst watershed in western Hubei Province were analyzed to propose two standard recession equations. This paper compares the standard attenuation equations of two watersheds, the discharge process of typical rainfalls, and the differences in runoff components under different flood peak flows. The results show that the water discharge process in the karst watershed is faster than that in the non-karst watershed, and its attenuation coefficient is 40% larger than that of the non-karst watershed. The base flow in the two watersheds is derived from the fissure medium that is the main groundwater storage space, but the proportion of the space occupied by the fracture media in the non-karst watershed is 8.8% greater than that of the karst watershed. With the increasing flood peaks, the proportions of surface runoff increase logarithmically, while the proportion of subsurface runoff decreases logarithmically. The runoff component of the karst watershed is more sensitive to the peak flow than that of the non-karst watershed, and its surface runoff ratio ranges from 4% to 40%, while the non-karst basin is always less than 10%. This paper quantitatively evaluates the water-conducting and water-storing functions of pipelines and fractured media in the watersheds, and the research results are beneficial for explorations in further describing runoff generation in karst watersheds. The results can provide a basis for water resources evaluation and improvement of hydrological models in karst mountainous areas.