黄土丘陵沟壑区小流域降雨入渗产流点面转化

Research on Transforming Relation from Point to Area of Infiltration Rate on Small Watershed for Hilly and Gully the Loess Region

在充分考虑小流域土壤入渗速率点面转化及地表结皮等影响因素在内的基础上 ,提出了小流域土壤入渗速率点面转化公式 :fm=fn×Sn/S×an×bn。以纸坊沟小流域为例 ,将实测的流域土壤入渗速率值 (点渗值 )利用上式进行转化 (面渗值 ) ,并与流域径流出口观测站由降雨径流观测值根据水量平衡原理推算出的面渗值进行对比 ,平均相对误差仅为 2 .42 %。初步得出流域土壤面渗率与不同治理度、年内 5～ 9月降雨总量间的单因子和复合因子高精度回归方程 。

Based on effect factors of transforming from point to area of infiltration rate and crust etc , put forward the formula of changing soil point's infiltration rate to area's rate on small watershed, which is fm=fn×Sn/S×an×bn Here, fm is the average soil area's infiltration rate(mm/min) on behalf of different land using models and topography and landforms, fn is the average soil point's infiltration rate(mm/min) under different land using models and topography and landforms through many field tests, Sn represents areas of different land using models(hm 2), S is Watershed's area(hm 2), an means correct coefficient thinking the effect of crust and system mistake etc , bn is the parameter thinking the effect of soil's water content Comparing the area's infiltration rate between transforming value and observing value, the result showed that relative error was only 2 42 percent , Preliminary gain the equations, which have high precision including single and fixed factors equations between soil area's infiltration rate and different soil control degree, rain quantity The method is advantageous for seeking rain, runoff, infiltration's changing trend after comprehensive control on small watershed