坡面冲刷过程中红壤分离速率定量研究

土壤分离是土壤坡面侵蚀产沙的必要途径和重要过程，准确预测土壤分离过程对完善土壤侵蚀物理模型具有重要意义。利用钢制变坡冲刷水槽，在不同坡度（8.8%～46.6%）和流量（0.2～1.0 L/s）组合下，研究了第四纪粘土发育红壤分离速率与流量、坡度以及水流剪切力、水流功率、单位水流功率3种水动力参数的关系。研究结果表明红壤分离速率是流量、坡度的幂函数，且坡度和单宽流量的多元回归方程能准确预测土壤分离速率（R²=0.966）；水流剪切力、水流功率和单位水流功率3个水动力参数指标与土壤分离率均呈线性关系，相关系数R²分别为0.950、0.965和0.849，水流功率是描述土壤分离速率最为确切的水动力参数；描述红壤分离速率的相关水蚀因子方程类型和前人研究结果相同，但表征土壤可蚀性的系数值相差较大。〖

QUANTITATIVE RESEARCH OF RED SOIL DETACHMENT RATE IN THE SLOPE SCOURING PROCESS

Soil detachment is the necessary approach and the most important process of soil erosion sediment yield.A precise prediction of this is significant to the development of physical based erosion model.Based on runoff scouring experiments by a hydraulic flume,the relationship of red soil detachment rate and slope,flow rate,shear stress,stream power and unit stream power were researched under different slope gradients(8.8%～46.6%)and runoff discharges(0.2～1.0 L/s)in this paper.The experimental results showed that soil detachment rates would be predicted by a power function of flow rate and slope(R2=0.966).Among shear stress,stream power and unit stream power,all of them were a linear relation with soil detachment rate(R2 is 0.949、0.965 and 0.848),and stream power was best related to soil detachment rate.The results indicated that describing the equation type of red soil detachment rate were considered the same to previous studies,however,the characterization of soil erodibility coefficient showed significant difference.