摘要
人工模拟降雨是研究坡地产流规律的一种有效手段。在华北石质山区东台沟流域的5m×10m的坡面径流小区中,进行了13场不同雨强和历时的人工模拟降雨试验,并同步监测了降雨、地表径流、壤中流、风化带出流和土壤含水量。结果表明,各层出流过程均呈现起涨与回落迅速的特点;相比较而言,地表径流和壤中流的退水很快,而风化带出流的退水则相对缓慢。地表径流量是研究小区内总径流的主要组成部分,其占了总径流量的60%以上,在大雨强下甚至能超过90%。径流系数主要受雨强、降雨量、土壤前期含水量的影响,它们的多元线性回归关系式为琢=0.002P+0.182i+4.88Wa-0.821。地表径流、壤中流、风化带的出流滞时与降雨强度均符合幂函数关系。可将退水常数分为2层,计算得到地表径流退水常数为0.75,壤中流和基岩风化带出流的退水常数为0.94;研究区主要以超渗产流方式为主,可以用Horton模型来描述,在不同雨强下均监测到了约0.10mm/min的深层渗漏,该值可以认为是该区的稳定入渗率。
Simulated rainfall is a valid tool to examine the runoff generation on the slope. 13 simulated rainfall experiments with different rainfall intensities and durations are completed in a 5 m × 10 m experimental plot in mountainous area of North China. Simultaneously, rainfall, surface runoff, soil-layer flow, mantel-layer flow and soil moisture are monitored respectively. From the results, it is found that the runoff process in all layers has the characteristics of rapid rise and fall. The recession of surface runoff and soil-layer flow is much faster than that of mantel-layer flow. Surface runoff, the main contributor, makes up more than 60% of the total runoff in the study area. It even exceeds 90% in the case of high intensity rainfall. Runoff coefficient is mainly influenced by rainfall, rainfall intensity and initial soil moisture. Their multiple linear regression function is α = 0.002P ＋ 0.182i ＋ 4.88Wa - 0.821. The relation between the rainfall intensity and the lag time of surface runoff, soil-layer flow and mantel-layer flow is shown to be exponential. The result also shows that the recession constant in this area can be divided into up and down layer, surface with 0.75 and soil-layer and mantel rock with 0.94, respectively. In this study area, the dominant infiltration excess runoff is simulated by Horton model. About 0.10 mm/min percolation is observed under the condition of different rainfall intensities, therefore the value is regarded as the steady infiltration rate.
出处
《地理学报》
EI
CSCD
北大核心
2005年第6期1021-1028,共8页
Acta Geographica Sinica
基金
国家自然科学基金项目(40371025)
中国科学院知识创新工程项目(CX10G-E01-08-02)~~
关键词
人工模拟降雨
华北山区
坡地
产流规律
simulated rainfall
North China mountainous area
slope
runoff generation process
