数字高程模型的空间分辨率对流域径流模拟的差异性影响分析

Analysis of the difference effect of spatial resolution of digital elevation model on watershed runoff simulation

数字高程模型(DEM)空间分辨率的精准确定,对于提高分布式水文模型输入水文信息的可靠性和有效性意义显著。文章选择北洛河流域典型区域作为研究对象,基于7种不同的DEM空间分辨率,利用ARCGIS软件,分别提取水文特征信息;在新安江模型物理参数意义研究的基础上,利用槽蓄曲线的坡度K和流量比重系数X之间的相关关系,确定参数,进行水文模拟;根据交口、状头水文站的实测数据,对模拟结果进行对比验证,结果表明:DEM空间分辨率越低,提取的水文特征信息越少;洪峰的模拟精度在分辨率200m之前减低缓慢,200m之后大幅降低。对比分析不同分辨率对水文模拟的影响,进而确定满足实际洪水预报的DEM分辨率大小。

The accurate determination of the spatial resolution of the digital elevation model(DEM)is significant for improving the reliability and validity of the input hydrological information of the distributed hydrological model.The article selects the typical area of the Beiluo River Basin as the research object.Based on 7 different DEM spatial resolutions,ARCGIS software is used to extract the hydrological characteristic information.Based on the study of the significance of the physical parameters of the Xin’an River model,the slope of the reservoir curve Correlation between K and flow specific gravity coefficient X,parameters are determined,and hydrological simulation is performed.Based on the measured data at the intersection and Zantou hydrological station,the simulation results are compared and verified.The results show that:the lower the DEM spatial resolution,the more hydrological data is extracted.The less feature information;the simulation accuracy of Hongfeng decreases slowly before the resolution of 200 m,and decreases sharply after 200 m.The effects of different resolutions on the hydrological simulation are compared and analyzed,and the DEM resolution that meets the actual flood forecast is determined.