潜在蒸散发公式对汉江流域径流模拟结果的影响

Abstract

采用FAO-56 Penman-Monteith(PM)、Hargreaves(Har)、Blaney-Criddle(B-C)、Thornthwaite(Tho)和Hamon(Ham)等5种潜在蒸散发公式计算汉江41个子流域的月潜在蒸散发量，将其作为蒸发输入数据代入两参数月水量平衡模型中模拟各子流域的月径流过程。模型参数的率定选用SCE-UA算法。径流模拟结果显示：1) 对于每一个潜在蒸散发计算公式，两参数月水量平衡模型在41个子流域上的效率系数的平均值均达到80%以上；2) 使用Ham方法模拟精度最优，每个子流域的效率系数均达到70%以上，PM法、Har和B-C法略差，Tho方法模拟精度最差。 The FAO-56 Penman-Monteith equation (PM) and four other temperature-based equations, i.e. Hargreaves (Har), Blaney-Criddle (B-C), Thornthwaite (Tho) and Hamon (Ham), were used to estimate the monthly potential evapotranspiration at 41 sub catchments in Hanjiang basin. The monthly runoff of each catchment was then simulated using the two-parameter monthly water balance model based on the estimated potential evapotranspiration data. The parameter calibration method was chosen to be SCE-UA algorithm. A comparison among the simulation results using five different monthly potential evapotranspiration equations showed that: 1) the average model efficiency of two-parameter monthly water balance model over 41 sub catchments is more than 80% for each different monthly potential evapotranspiration equation; 2) the simulation result is best when using the Ham equation, with the model efficiency at each of 41 catchment larger than 70%, while the results of the PM, Har, and B-C equations are relatively poor, and the Tho method is the worst.