DEM空间分辨率对流域水文特征信息提取及径流模拟影响研究

Impact of DEM Spatial Resolution on Hydrological Characteristics Information Extraction and Runoff Simulation

DEM是构建分布式水文模型的重要输入。以岷江上游为研究区,基于8种不同空间分辨率DEM构建SWAT模型,研究分析DEM空间分辨率对流域水文特征提取及径流模拟影响。研究表明,DEM空间分辨率越低,洪峰模拟精度越低,模拟流量与实测流量间的误差越大,曲线吻合度越低;DEM空间分辨率由25m降低到200m时,径流模拟误差变化不明显,而DEM空间分辨率由200m降低到3 200m时模拟误差显著增大;另外,DEM空间分辨率与径流总量的模拟精度间未表现出显著相关性。

Digital Elevation Model（DEM） is an important parameter to build a distributed hydrological model. In this paper, A SWAT hydrological model for the upstream of the Minjiang River was constructed, and the impact of spatial resolution of DEM on hydro-logical characteristics extraction and runoff simulation was analyzed. The results show that the lower DEM spatial resolution will lead to lower peak flow simulation accuracy, bigger error between simulated and measured flow. When spatial resolution of DEM decreases from25 m to 200 m, the accuracy of simulation will decline a little, and when spatial resolution decreases from 200 m to 3200 m, the accuracy of simulation will decline significantly. In addition, the impact of DEM spatial resolution on runoff of simulation is not significant.