基于双源蒸散发的新安江模型在淮河上游的应用

Research on the Application of Xin'anjiang Model Based on the Dual-source Evapotranspiration Model in the Upper Huaihe River Basin

传统的新安江模型在计算流域蒸散发能力时仅依据非常有限的几个蒸发站的蒸发皿实测水面蒸发乘以一个折算系数来获得,不能考虑土地利用/覆被、气候特征、植被叶面积指数等因子的时空差异性和土壤特性、流域地形的空间差异性对流域蒸散发量影响。通过将考虑植被叶面积指数动态变化对蒸散发影响的双源蒸散发模型与新安江模型集成,改进了新安江模型的蒸散发计算模块,并以淮河息县水文站以上流域为研究区,以日为时间尺度,基于地形、土地利用、气象及水文资料对息县以上流域2000~2008年降雨径流过程进行模拟,结果表明,基于双源蒸散发的新安江模型能有效地模拟淮河上游降雨径流过程,满足模拟精度要求。研究成果为改进新安江模型中蒸散发计算模块提供了依据,也可为改进的新安江模型在其他流域的应用提供参考。

Pan evapotranspiration data measured by the very limited evapotranspiration stations,are usually used as an input of the traditional Xin＇anjiang model and multiplied by apan coefficient to obtain the potential evapotranspiration.Meanwhile,PE is often assumed even without considering the spatial heterogeneity of soil properties and topological characteristics and the temporal heterogeneity of land use/cover,climate characteristics,vegetation leaf area index（LAI）and other factors.The aim of the paper is to improve the model of evapotranspiration of Xin＇anjiang model by integrating the distributed dual-source potential evapotranspiration model adopting dynamic daily LAI with Xin＇anjiang model.Based on the topography,land-use,hydrological,and meteorological data in the upper Huaihe River basin,daily runoff was simulated during 2000-2008.The results showed that the Xin＇anjiang model based on the dual-source potential evapotranspiration model could effectively simulate the upper Huaihe River basin daily rainfall-runoff process and achieve high simulation precision.Thus it can provide a method support for the calculated evapotranspiration to improve Xin＇anjiang model and a reference for other watershed daily runoff simulations.