SWAT分布式水文模型在黑河干流山区流域的改进及应用

Improvement and Application of GIS-based distributed SWAT Hydrological Modeling on High Altitude,Cold,Semi-arid Catchment of Heihe River Basin,China

在集成地理信息系统(GIS)和遥感(RS)技术的SWAT(SoilandWaterAssessmentTool)分布式水文模型改进的基础上,对黑河干流山区流域出山径流进行了模拟。SWAT GIS按不同的地形、土壤类型、土地利用或覆盖类型将整个流域划分成157个具有相似水文特征的水文响应单元(HRU)。通过模拟结果比较,表明浅层蓄水层回归因子(基流回归因子)、海拔高度带的划分分别对黑河干流山区流域地下径流和融雪径流过程有重要的影响,是该模型模拟精度高低的关键。通过参数的调整,1990～2000年月平均径流模拟结果显示,莺落峡站出山径流模型效率系数R2达到0.88,相关系数r2接近0.91。

SWAT(Soil and Water Assessment Tool),a distributed hydrologic model integrated with geographic information system(GIS) and remote sensing(RS) to simulate the hydrological processes and stream flows,was improved and applied to a high altitude,cold,semi-arid Yingluoxia catchment located on Heihe river basin,northwestern China.In corresponding to different topography,soil types,land use/cover classifications over the 10 009 km^2 catchment,SWAT-GIS delineated the watershed based on 120 m resolution DEM into 157 simulation subwatersheds,each watershed was thought a unique Hydrological Response Unit(HRU) that owns the similar hydrological characteristics.Numerical experimental simulations on the Yingluoxia catchment suggested that the shallow storage recession factor(base flow recession factor),the altitudinal range discrimination was very essential to the well simulation of base flow and snow-melting process,and the accurate determination of shallow storage recession factor and successive simulation of snow-melting process on different altitude ranges are the key factor determining the simulation resolution.Through adjustment of the parameterization,satisfied simulation results were obtained with the accuracy of 0.88 for Nash-sutcliffe coefficient,0.91 for correlation coefficient over the 11 years continuous simulations on monthly discharges.