峰丛洼地的坡地径流成分划分

Separating Karst Slope Runoff in Peak Cluster Area

峰丛洼地的石质坡地具有独特的包气带结构和产流模式,其表面岩石裸露,土壤薄且呈现斑块状分布,下部发育表层岩溶带。表层岩溶带的存在决定了石质坡地的产流模式。原本不透水的岩石表面成为"筛子",表层岩溶带和下部包气带之间的界面成为重要的产流界面,称之为表层岩溶带产流。石质坡地的径流是表层岩溶带产流、超渗产流、饱和产流的集合。由于岩溶动力系统的差异导致来自不同界面的径流的温度、pH、电导率、方解石溶解饱和指数(SIc)和二氧化碳分压(PCO2)也不同。利用径流的物理、化学曲线对石质坡地的径流进行初步的定性划分,将径流分为洪峰和基流。洪峰的上升段由超渗产流和饱和产流构成,退水过程以及基流则主要是由表层岩溶带径流提供。

Karst slope in peak cluster area is charactered by bare rock,soil mend and epikarst.It is the epikarst which makes runoff in karst slope different.Bare limestone which should be impermeable becomes much permeable because of epikarst.And that epikarst is more permeable than vadose zone below,which makes foundation for epikarst runoff.Runoff in rocky slope is combined by the runoff yield under saturated storage and the runoff yield under excess infiltration and epikarst runoff.The difference of karst dynamic systems leads to different temperature,pH,electric conductivity,saturation index of calcite and CO2 partial pressure.Hydrograph of rocky slope runoff can be separated according to corresponding hydro-chemical graphs.Result of hydrograph separating is that hydrograph is divided into two part,namely flood and base flow,and that the rise part of graph comes from runoff yield under saturated storage and the runoff yield under excess infiltration,while the base flow and attenuation part are contributed by epikarst runoff.