水平分辨率对提取数字流域地貌特征值的影响

Influence of horizontal resolution on extracting characteristrics of digital river basin

为了研究水平分辨率对提取数字流域地貌特征值的影响,论述了地貌特征坡度和汇流时间的计算方法,采用基于高程双线性多项式内插方法获得了多种水平分辨率的DEM,分析了水平分辨率对于坡度、霍顿数和平均汇流时间影响。研究表明:不同坡度计算方法产生坡度之间存在差异;不同水平分辨率对于坡度、霍顿数和平均汇流时间影响显著,而对于河网长度和河源数影响不明显。

The purpose of this article is in order to study the influences of horizontal resolution on extracting watershed features. In this article, the authors discussed the calculation method of geomorphic feature slope and concentration time, adopted the bilinear polynomial interpolation method based on elevation to obtain various horizontal-resolution DEMs, and analyzed the influences of horizontal resolution on slope, Horton number and average concentration time. The results showed that, there are differences between the slopes calculated in different methods and the influences of different horizontal resolution on slope, Horton number and average conflux time are obvious, but not obvious on river network length and the number of sources.