The Effect of DEM Resolution and Flow Direction Algorithms on Contributing Area Calculation
Resource
地理學報, 39, 071-090
Journal
地理學報
Journal Issue
39
Pages
071-090
Date Issued
2005-03
Date
2005-03
Author(s)
Abstract
Digital Elevation Model (DEM) plays a very important role in hydrological simulation. Hydrological parameters such as contributing area can be calculated from DEM automatically. Contributing area is a common parameter for delineating channel cells and for evaluating the potential of soil erosion. But calculation of contributing area is usually affected by DEM resolution and flow direction algorithms. This paper presents a case study that evaluates these effects in a sub-watershed of the Chenyulan His. Three flow algorithms w4re used to calculate the contributing area area at different DEM resolutions. The result shows that within the same DEM resolution, the hybrid model retains the advantage of both single-flow and multi-flow models and yields the most reasonable output. However, some spatial errors occur when coarser resampled DEMs were used. The only parameter in the hybrid model, the flow direction threshold, strongly affects the simulated result. The higher the DEM resolution is, the smaller the flow direction threshold should be. Adjustment of the flow direction threshold according to DEM resolution with a geometric ratio facilitates conversion in the calculation of the hybrid model and enables the distinction between “river unit” and “slope unit”.
Subjects
集流面積
DEM解析度
流向演算法
Contributing area
DEM resolution
Flow direction algorithm
Type
journal article
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