坡面水流分离崩岗崩积体土壤的动力学特征

The Dynamic Characteristics of Soil Detachment of Slumping Deposit by Surface Runoff in Benggang

利用变坡式水槽,在坡度(20°,25°,30°,35°,40°)和流量(1.1,2.2,3.3,4.4,5.5L/min)下进行崩岗崩积体土壤的分离试验。结果表明:流量对土壤分离速率的作用大于坡度,土壤分离速率与坡度及流量呈线性相关;水深对土壤分离速率的影响大于坡度,土壤分离速率与坡度及水深呈线性相关;土壤分离速率与水流流速呈指数函数关系;水流剪切力、水流功率及单位水流功率与土壤分离速率之间的关系均为线性关系,其中,水流功率和水流剪切力可以很好地描述崩积体的土壤分离速率。

The study was conducted to analyze soil detachment process of slumping deposit in Benggang on the conditions of the flow discharge（1.1, 2.2, 3.3, 4.4, 5.5 L/min） and slope gradient（20°, 25°, 30°, 35°, 40°）. The results indicated that： Soil detachment rate increased with both flow discharge and slope gradient increasing. However, the effect of flow discharge on soil detachment rate was greater than the slope on soil detachment rate. The influence of water depth on soil detachment rate was greater than the slope on soil detachment rate. Soil detachment rate was linear correlation with slope and depth. Soil detachment rate was exponential function relationship with flow velocity. Among three current used hydro-dynamic parameters of shear stress, unit stream power, and stream power, there was closely relationship between soil detachment rate and stream power, soil detachment rate and stream shear stress.