基于DEM导出的水文地形参数对比研究——在ArcGIS和Rivertools环境下

Comparative study on hydrological terrain parameters based on DEM using Rivertools and ArcGIS

对比分析了在Rivertools和ArcGIS 2种软件环境下基于DEM提取水文地形参数的差别。结果表明:Rivertools在计算DEM填洼时较ArcGIS软件好,并可自动生成多项其他的水文地形参数,使用也更为方便,但Rivertools的河网分级方法单一,河道的裁剪只能在同一河流级别下进行;而ArcGIS的河网分级方法不唯一,且河道的裁剪不受河流级别的限制,但是要求用户对研究区域的河网有相当的了解,否则在河网的自动提取中容易与实际产生较大的偏差。鉴于2种软件各自的特点,在实际应用中应将两者结合起来,充分发挥每个软件的优点。同时,本文对基于不同精度(5m×5m、10m×10m、25m×25m、50m×50m和100m×100m)DEM导出的水文地形参数(河网长度、河网密度、高程、流域面积)进行了对比分析。结果表明:在一定的DEM精度范围内,用Rivertools软件基于DEM导出的河网总长、流域面积等水文地形特征参数与实际情况吻合得更好,但DEM精度对以此导出的水文地形特征参数更为敏感,而ArcGIS环境下DEM精度对地形特征参数的影响较小。

This paper compares the extracted hydrological terrain parameters based on DEM using Rivertools and ArcGIS.The results show that it is better to choose Rivertools to extract hydrological parameters,especially for creating a depressionless DEM;however,the method of stream order classification by Rivertools is too single,among which the river＇s clip only can be done in the same stream order.Comparatively,ArcGIS has more ways to classify stream order,and the river＇s clip is not limited by stream order;however,ArcGIS software requires user must know the river system of the research area very well,otherwise,big error could be made during the extraction.According to the Pros and Cons of the two kinds of software,user should combine two kinds of software together and make full use of each software＇s advantages.Meanwhile,this paper compares the differences between extracted hydrological terrain parameters（length of river system,density of river system,elevation and the area of watershed） based on different resolution of DEM（the grid of DEM is 5 m × 5 m,10 m × 10 m,25 m × 25 m,50 m × 50 m and 100 m × 100 m,respectively） under Rivertools and ArcGIS.The results show that the extracted hydrological terrain parameters from Rivertools are more accurate than that from ArcGIS in somerange of DEM resolution,while the effect of DEM resolution on extracted hydrological terrain parameters using ArcGIS is smaller than that using Rivertools.