基于SWAT模型干旱区内陆河流域径流成分的模拟分析——以玛纳斯河上游为例

Simulation analysis of inland river basins in Arid Area runoff components——A case of the Upstream in Manasi river

干旱区内陆河流域径流主要来源于山区降水,但降雨产流和融雪产流对山前绿洲水资源的时空供给周期与强度有很大不同,因此区分径流成分对流域的水文预报和水资源配置具有重要意义。本文以西北干旱区典型内陆河流域——玛纳斯河流域上游为例,基于历史逐月径流资料(1980-2000年),应用SWAT分布式水文模型对玛纳斯河上游径流成分进行模拟分析。分析结果表明:SWAT分布式水文模型可以有效的模拟玛纳斯河的径流变化特征,在率定期和验证期,Nash-Sutcliffe效率系数以及决定系数r^2分别高于0.81和0.89,达到评价标准。基于水量平衡原理的计算结果表明:多年流域的实际蒸散发量、地表径流量、土壤对地下水补给量、地下侧流量分别占降水量的53.54%、25.51%、17.60%和3.35%,进一步分析表明雪冰融水占降水量的64.50%,说明该流域的径流量主要来自雪冰融水,但各月降水量变化趋势与地表径流量的变化趋势具有一致性,说明大部分降水转化为径流的时间较短。该研究对流域水文预报和水资源调控具有参考意义。

Precipitation in mountainous area is the most important part of the runoff in inland river basin over the Arid Areas.But there are great differences in supply period and intensity in the Piedmont Oasis between rainfall runoff and snowmeltrunoff, so it is important to distinguish runoff components for hydrological prediction and water resources allocation. This papertook the upstream of the Manas River Basin as the example of the typical inland river basin in the arid area of NorthwestChina Runoff distribution in the upstream of Manasi river is simulated and analyzed based on historical monthly runoff data（1980-2000） by SWAT distributed hydrological model. The results show that the SWAT distributed hydrological model cansimulate runoff characteristics of Manasi river effectively in the calibration and verification period; the Nash-Sutcliffe efficiencycoefficient and the coefficient of determination 2are above 0.8 and 0.92, which reach the evaluation criteria of decisioncoefficient. Based on the principle of water balance, the actual evapotranspiration, the surface runoff, soil water supply andunderground water flow rate of the precipitation account for 53.54%, 25.51%, 17.60% and 3.35%, resectively. The furtheranalysis indicates that snow and ice melt water accounted for 64.50% of the precipitation and the basin runoff mainly comesfrom the snow ice melting. But the change trend of monthly rainfall and surface runoff is consistent, which shows that mostprecipitation converts to runoff fora short time. Therefore, this study hasa reference significance for the hydrological forecastingand water resources regulation.