基于DEM数字河网提取时集水面积阈值的确定

Determination of drainage area threshold for extraction of DEM-based digital drainage network

介绍了基于DEM流域信息提取数字流域河网的一系列过程,提出集水面积阈值的设定对数字流域河网提取精度的影响.根据河网密度和河源密度与集水面积阈值的关系确定合理的集水面积阈值,并以宛川河流域为例,得出利用Arc Hy-dro软件提取宛川河流域河网时合理的集水面积阈值应为4 km2.

A series of DEM-based process to extract drainage network are introduced. The different DEM-based drainage network is obtained by varying drainage area threshold, and the densities of headwaters and stream network change with drainage area threshold. A method in which the relation between the densities of headwaters or drainage network and the drainage area threshold is used to produce an ideal drainage network is proposed. The drainage network extracted by Arc Hydro in Wan-Chuan basin is ideal when the drainage area threshold is 4 km2.