贵州普定陈旗喀斯特泉的降雨-径流响应特征分析

本文以贵州省普定县陈旗喀斯特泉流量为研究对象,采用相关分析和谱分析方法,分析降雨-出口泉流量的响应特征,统计结果表明,该喀斯特流域出口处泉流量对降雨表现出三种响应滞时,分别为短时段、中等时段和长时段响应。对应的响应滞时长度分别为2~4 h、47~49 h和176~290 h。对比流域山坡上部和坡脚两处降雨-泉流量响应特征,结合野外水文地质调查与实验,分析了表层岩溶带发育厚度、多重裂隙渗透性等水文地质条件对降雨-泉流量响应特征的影响机制。山坡上部表层岩溶带厚度较薄,且表层裂隙更为发育,导致山坡上部泉对降雨的响应更迅速,各时段滞时均小于全流域对应时段滞时。

Rainfall-runoff Response Characteristic Analysis of Chenqi Karst Watershed in Southern China

The study is implemented in a small watershed of Chenqi within Puding Country, Guizhou Provence. The spring discharge in basin export responses to rainfall can be quantitatively analyzed by using the correlation analysis and spectra analysis methods. The result showed that:the rainfall-runoff response time lags could be classified into three kinds:short-time response, medium-time response and long-time response. The time lag of short-time response of spring discharge to the rainfall was 2~4 h. The time lag of medium-time response was 47~49 h. The time lag of medium-time response was 176~290 h. Combined with the field hydrogeological investigation and experiment, contrasted with response characteristics to rainfall of two springs in upper slope and foot of the slope, the influencing mechanism of hydrogeological condition on rainfall-runoff response characteristics was analyzed. The related hydrogeological conditions include epikarst zone thickness and multiple fracture permeability. The epikarst zone thickness is thinner, and the surface fracture is more developed in upper slope, resulting in that rainfall-runoff response is faster, and the three kinds of time lags are all smaller than other areas in the whole watershed.