渭河上游流域多数据源DEM水系提取对比研究

Comparative study of the upper Weihe River drainage extracted from different DEMs

随着空间对地探测和计算机技术的迅速发展,越来越多新的DEM数据源产生,不同DEM数据提取的水系结果存在哪些差异,如何选择合适的DEM数据,目前仍缺乏相关研究,且不同数据所提取同一水系难以进行有效的对比分析。本文选择可公开下载的DEM数据(SRTM 90m、ASTER GDEM 30m和ALOS World 3D30m),提取了渭河上游流域盆地水系,并与我国1∶5万25mDEM数据提取的水系进行平面和主河道剖面对比。研究结果表明:ALOS World 3D30m数据提取的水系在平面上与1∶5万25m数据最为贴近,水系高程值ALOS World 3D30m数据与1∶5万25m数据最为吻合;SRTM 90m和ALOS World 3D30m主河道剖面高程值与1∶5万25m数据线性拟合最好。综合认为,ALOS World 3D30m数据能够替代1∶5万25m DEM数据,进行渭河上游水系提取分析。

Rapid development of space-to-Earth detection and computer technology prompts that more and more new DEM sources are released.The study on the difference of results extracted from various DEM sources and on how to choose appropriate DEM are now still lacked;it is also difficult to conduct effective comparison analysis on the extracted drainage from various DEMs.This paper first extracts the drainage of the upper Weihe River basin using the four open DEMs,namely,SRTM 90 m,ASTER GDEM 30 m,ALOS World 3 D 30 m,and then carries out comparison on the planar and trunk channel profiles extracted from 1∶5000025 m DEM.Results suggest that:the drainage on the planar extracted from the ALOS World 3 D30 mDEM is the closest to that extracted from the 1∶5000025 m DEM;the drainage elevation values extracted from the ALOS World 3 D30 mDEM is most closely match with that extracted from the1∶5000025 mDEM;the trunk stream profile elevation values extracted from SRTM 90 mDEM and ALOS World 3 D30 mDEM are best linearly fitted with that extracted from the 1∶5000025 m DEM.We therefore believe that ALOS World 3 D30 m DEM can replace 1∶5000025 m DEM for drainage extraction and analysis of the upper Weihe River.