基于山坡Pe'clet数推求土壤水蓄水容量

Soil Storage Capacity Calculation by Using Hillslope Pe'clet Number

山坡几何形状影响流域水流汇聚,土壤厚度则影响径流生成,在水文过程模拟中考虑山坡地貌因素十分必要。基于山坡单元,通过研究水文相似因子山坡Pe'clet数(Pe数)在不同流域空间分布的规律,发现山坡Pe数的累积分布曲线与流域蓄水容量曲线类似,由此确定两者之间的关系式。实例验证表明,利用山坡Pe数推求流域土壤水蓄水容量的方法可行。利用关系式反推新安江模型中的参数B,对比率定参数B的径流模拟结果与推求参数B的径流模拟结果表明,推求参数B的模拟结果整体较好,避免了新安江模型中参数B的率定,进一步验证了该方法的合理可行性。

The shape of hillslope geometry affects the flow concentration,and the soil depth affects the formation of runoff.So,it is important to consider geomorphologic features of hillslope in simulation of hydrological process.Based on the hillslope scales,cumulative frequency curve of different basin's hillslope Peclet number(Penumber)shows a similar line style with that of storage capacity,thus this paper identifies the relationship between the hillslope Penumber and the storage capacity.The practical simulation results show that it is feasible to derive the soil storage capacity with the hillslope Penumber.The parameter Bin Xin'anjiang model was deduced by using the above relational expression.Comparing the calibrated parameter B with the derived parameter B,the simulation results of the derived parameter Bis better as a whole.Thus,it avoids the calibration of parameter Bin Xin'anjiang model.The rationality of the proposed method was further verfied.