喀斯特地区流域洪水退水过程分析——以贵州省黄洲河流域为例

Analysison flood recession progress in karst watershed: case of Huangzhou River Basin in Guizhou Province

为研究喀斯特地区流域洪水退水的过程特性,以贵州省黄洲河流域为研究对象,对流域径流进行基流分割,运用指数型退水模型公式对退水过程进行模拟。结果表明:(1)黄洲河流域洪水过程的总流量变化与基流变化呈现正相关,退水过程受降雨时长、流量大小以及流域岩性特征等因素的影响。(2)地表径流退水速率大于地下径流退水速率,流域内大量的岩溶孔隙和裂隙存在使地下径流退水加快。(3)起退流量为11.99~381.81 m3/s,退水系数的范围为0.033~0.084,退水系数越大,暴雨洪水时间越短,反之越长。(4)指数型退水模型能够较好地模拟黄洲河流域的退水过程。

In order to study flood recession in karst watershed,flood recession in Huangzhou River Basin of Guizhou province was simulated by exponential model formula and baseflow separation method.The results showed that:(1) There was a correlation between total flow variation and baseflow variation in flood process of Huangzhou River Basin,and the flood recession was effected by rainfall duration,flow size and lithologic characteristics of the basin.(2) Recession rate of surface runoff was faster than that of underground runoff,large number of karst pores and cracks in the basin accelerated the drainage of underground runoff.(3) Initial recession flow was between 11.99 m~3/s and 381.81 m~3/s,and recession coefficient ranged from 0.033 to 0.084.The larger the recession coefficient was,the shorter the duration of rainstorm and flood was,and vice versa.(4) Exponential model for flood recession could simulate the flood regression in Huangzhou River Basin.