下垫面含水状态与降雨产流关系研究

通过仿雨试验,研究了土壤剖面平均含水量对降雨产流特征的影响.结果表明:(1)土壤剖面含水状态对降水在下垫面产生积水形成径流时间有显著影响,下垫面积水时刻与土壤剖面平均含水量的饱和度、降雨强度呈乘幂的函数关系.(2)在相同土壤剖面含水状态条件下,相同降雨时段内,径流系数γ与降雨强度i呈线性关系,径流系数γ随着降雨强度i的增大而增大;当土壤剖面平均含水量的饱和度ω≤0.70时,径流系数与时间的函数关系为高次多项式;当土壤剖面平均含水量的饱和度ω>0.70时,径流系数与时间的函数关系为自然对数.

Study on the Relationships between the Soil Moisture Condition of Underlying Surface and Rainfall-runoff

The effect of soil average water content of profiles on rainfall-off feature was studied by an imitaion raining experiment.The results indicated that:(1)The soil moisture had marked influence on the time of underlying surface producing hydrops and forming runaff.It was the power regression relation that the underlying surface hydops moment,saturation level of soil section average water content and rain strength.(2)In the condition of same soil profile moisture it was the linear regression relationship between the runoff coefficient and the rain strength.When the saturation level of the soil profile average water content was smaller than 0.70 or equals 0.70,and the relationship between the renoff coefficient and time was a higher polynomial regression equation;when the saturation level of the soil profile average water content was greater than 0.70,the relationship between runoff and time was logarithm.