Retaining Relative Height Information: An Enhanced Technique for Depression Treatment in Digital Elevation Models

Water

Jing Zheng¹  Hanxin Gao²  Bo Chen²  Chunying Ma²  Peijun Shi²  Yao Xiao² 

[1] Guangdong Climate Center, Guangzhou 510640, China;State Key Laboratory of Earth Surface Processes and Resource Ecology, Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China;

关键词: depression treatment;    drainage network;    sinks and depressions;    digital elevation model;    hydrologic analysis;   

DOI  :  10.3390/w13233347

来源: DOAJ

【 摘 要 】

This study presents an enhanced variant of the priority-flood based algorithm proposed by Wang and Liu for treating depressions in digital elevation models (DEMs). The enhanced variant redefines spill elevation, the key concept of the original algorithm, as the lowest elevation that a pixel needs to have to ensure a non-ascending path toward the border of the DEM, plus the larger of a small number (~0.001) and the difference between the unaltered elevation values of the focal pixel and its immediate downhill neighbor. This redefinition is adopted to obtain an intermediate elevation surface to direct flow and ultimately to carve the original DEM. Each carving starts from a depression bottom and propagates downstream until a downhill cell is guaranteed in the original DEM. Tests of these algorithms on a complex terrain of the 260,000 km² Sichuan structural basin in China shows that the enhanced algorithm maximally preserves the original flow directions and extracts realistic drainage networks. Retaining the relative heights, and therefore flow directions, of cells within depressions allows the new algorithm to offer a depressionless DEM with small modification of its origin for further hydrologic applications. The enhanced depression treatment algorithm is provided as the freely available tool BNUSinkRemv.

【 授权许可】

Unknown