基于DEM和ArcGIS的浐灞流域水文特征提取研究

基于DEM数据,在ArcGIS环境下,提取浐灞流域的坡度、坡向地形特征以及不同集水阈值下的流向、河网密度、河源数等水文信息。结果表明:集水阈值和河网密度、汇流面积之间存在幂函数关系,阈值越大,河网越稀疏;对其二阶求导确定了流域的最佳阈值为8000,避免了以往确定阈值的主观随机性。运用ArcGIS嵌套软件TauDEM提取了最佳阈值的河网,并利用Strahler法对河网进行了分级。提取的河网与浐灞自然水系基本吻合,流域地形水文特征符合流域概况,可直接作为水文模型参数,为浐灞流域的分级管理提供数据支持,该方法提高了建立流域水文模型的效率,成本低且精度高。

Research on hydrological characteristics extraction of Chanba Basin based on DEM and ArcGIS

Based on DEM data in ArcGIS environment, the gradient, topographic features of the slope in Chanba basin, the flow direction, river network density and the number of rivers under different water catchment threshold were extracted. The results showed that the relation between drainage threshold and drainage density or watershed area followed a power-exponential function, and the higher the threshold value was, the sparser the network was. The optimum threshold value of the basin was 8000, which determined by the second order derivative, which avoided the subjective randomness. The best threshold of river network was extracted by ArcGIS nested software TauDEM, and the river network was stratified by Strahler method. The extracted river network matches well with Chanba natural water system. The topography and hydrology characteristics of the basin are in line with the general situation of the basin, which can be used as hydrologic model parameters directly to provide data support for the ecological environment management of Chanba River Basin. The method improves the efficiency of the hydrological model, and has the advantage of high precision and low cost.