基于SRTM DEM的浙江八大水系特征提取与精度分析

Feature Extraction and Precision Analysis of the Eight Drainages in Zhejiang Based on the SRTM DEM

选用SRTM DEM(90m)数据,利用Arc Hydro Tools分别实现了浙江八大水系(除运河流域)的边界提取和流域划分。通过计算流域的相关水系因子(如流域面积、流域周长、流域平均分支比等),以及与1/25万数字水系河网的比较,进行提取水系的精度分析。结果表明,流域面积是反映水系提取精度的重要指标;其他因子反映较小。同时,应用SRTM DEM数据提取水文特征具有较高的精度,显示了其在更新水文研究基础数据方面的优势。

SRTM DEM data is choosed,and used Arc Hydro Tools,realized the boundary and watershed division of the eight drainages in Zhejiang.Through the calculation of the relevant basin Morphological parameters（such as watershed area,watershed perimeter,watershed average branching ratio,etc）,and comparison with 1 /250 000 digital drainage of river network to analysis the water precision.The results show that,the watershed area is an important index to reflect drainage extraction accuracy,the reflection of other factors are smaller;At the same time,use SRTM DEM data to extract hydrological feature has a high precision,shows its advantage in updating hydrological based data.