DEM分辨率对SWAT模型水文模拟的影响研究  

Response of DEM Scale Effect and Hydrological Simulation of SWAT Model

作　　者：吴江[1] 胡胜[1] WU Jiang HU Sheng(College of Urban and Environmental Science, Northwest University, Xi＇ an 710127, China)

机构地区：[1]西北大学城市与环境学院,西安710127

出　　处：《灌溉排水学报》2016年第11期18-23,共6页Journal of Irrigation and Drainage

基　　金：西北大学研究生自主创新项目(YZZ15011)

摘　　要：以灞河流域为研究区,以DEM的分辨率（30~500 m）作为变量,进行了DEM空间分辨率对SWAT模型水文模拟的敏感性研究。首先,不同分辨率DEM作为输入数据构建SWAT模型并进行模拟,其后将模拟结果与灞河流域马渡王、罗李村水文站的实测流量比对进行相对偏差计算,最终采用均值变点统计方法,以模拟结果的相对偏差为研究对象,探讨分析了DEM尺度效应的最佳尺度拐点。结果表明,DEM分辨率的变化深刻影响着水文模型流域特征的提取,其分辨率的降低会导致流域的最大坡度、平均坡度、河道长度均发生衰减,同时流域形状、子流域数量也会发生不同程度的改变;随着DEM分辨率的逐渐降低（30~150 m）,径流模拟的结果与实际流量的相对偏差逐渐增大,但增长幅度不超过11%。当DEM空间分辨率低于150 m时,相对偏差变化并不显著。均值变点法能够很好地识别拟合曲线发生明显变化的拐点,通过统计分析发现DEM分辨率为150 m时即为模拟结果相对偏差变化趋势逐渐由陡变缓的变化最佳拐点。Taking Bahe River basin as the study area, a sensitivity study on hydrological simulation of SWAT model and DEM spatial resolution was carried out with DEM resolution （30-500 m） as the only variable. First, different DEM resolutions were used as the input data to build the SWAT model and traffic simulation was ap- plied, and then the simulation results and the measured discharge of Maduwang and Luolicun hydrologic stations were statically analyzed in the Ba River basin by the relative deviation. Finally, the statistical method of mean change-point was introduced; and the optimum scale inflection point of DEM scale effects with the relative devia- tion of simulation results was discussed as the research object. The results showed that： the changes of DEM reso- lution had influence on deriving the watershed features of the hydrological model. The decreasing of its resolu- tion would lead to the basin＇ s maximum slope, average slope and river length, and the shape of the basin and the number of its sub-basins on different levels would be changed simultaneously. With the gradual decreasing of DEM resolution （30~150 m）, the relative deviation of runoff simulation results and the actual flow rate in- creased gradually, but the growth rate was less than 11%. When the DEM spatial resolution was less than 150 m, there was no significant change of the relative deviation. When the fitted curve changed obviously, the inflection point could be well identified by mean change-point method. DEM resolution of 150 m was the optimum inflec- tion point, of which relative deviation trend of simulation results shifted from a sharp change to a slow change gradually.

关 键 词：SWAT模型 DEM分辨率 相对偏差 均值变点分析 灞河流域 

分 类 号：P333[天文地球—水文科学]