坡地雨水资源潜力分析及径流侵蚀的动态变化

通过人工模拟降雨,对宁南山区坡地改造后不同坡度的自然坡面进行试验研究。结果表明:相同降雨量下,降雨强度与土壤贮水量补充呈反比,入渗深度随坡度增大减小。比较人工降雨和双环法对稳渗速率的影响,人工降雨测定的土壤稳渗速率小于双环法测定的稳渗速率,双环法所测定的土壤稳渗速率与人工降雨法测定的土壤稳渗速率之间呈线性函数关系。对水平沟水分补充随坡度和雨强增大而增大,大雨对水平沟水分补充有重要意义。产沙动态分析,雨强较大时,随时间推移,单位体积泥沙含量递减,在较小雨强下,随时间推移,单位体积泥沙含量呈递增趋势。雨强和土壤侵蚀模数的关系符合幂函数方程:Q=0.017I2.5442

Dynamic Change of Runoff Infiltration and Potential Analysis of Rainwater Resource on Slope Land

The matural sloping face of different gradient slope in the hilly region in south of Ningxia after changing sloping field were experimentally studied by means of artificial rainfall simulation. The results showed that the rainfall intensity were in inverse ratio to supplement soil conserving water, infiltration depth were reduced with the increase of gradient. The effect of artificial rainfall simulation and doubt ring method to steady infiltration rate were compared, the soil steady penetrating velocity measured by artificial rainfall was less than one measured by two loop method, and there were linear function relationship between two values. The water supplement to level trench increased with the increase of the gradient and rainfall intensity, the downfall were significant to the water supplement to level trench. The analysis of sediment yield dynamics showed that the sediment content per volume descended with time process under bigger rainfall intensity, while increased by degrees under smaller rainfall intensity. The relationship of rainfall power and soil erosion modulus accorded with the power function equation:Q=0.017 I~(2.5442)