SRTM无效数据填充方法在数字河网提取中的应用

为验证最新全球免费高分辨率航天飞机雷达地形测量任务(SRTM)数字高程模型(DEM)数据在水文学中的应用效果,以湖北省清江流域为例,利用SRTM数据进行了流域数字河网提取,通过与数字化地形图DEM提取的数字河网比较,指出SRTM数据中普遍存在的无数据区域是其进行水文分析的最大障碍,常用的SRTM无数据区域填充方法会使河道高程出现较大误差,导致提取的数字河网出现偏差.为解决上述问题,提出了在实际数字化河网限制下的SRTM数据无数据区域填充方法,计算结果表明,利用该方法处理后的SRTM数据更符合实际情况,提取的数字河网也与实际情况相符.

A void filling method for SRTM and its application to the extraction of drainage networks

The drainage network was extracted by shuttle radar topogrphy mission(SRTM) at Qinjiang Valley in Hubei province.In comparison with drainage networks extracted by the digitalized topographic contour digital elevation model(DEM),it was seen that the popular voids in SRTM should be the main obstacle for hydrological analysis.Widely used methods for filling void of SRTM can cause many errors along the river and lead the derived drainage networks to make deviation.Regarding to these problems,a void filling method for SRTM was proposed on the basis of the actual digitalized drainage networks.The result showed that digital elevations and extracted drainage networks with void-free SRTM processed by the proposed method were better than the traditional void-filling method and applied well with the actual elevations and drainage network basically.