论文部分内容阅读
直接将浮点型DEM数据转换为整数型,会改变某些栅格的坡向和坡度,增加DEM中平坦区域和提取的河网中伪河道的数量.为了消除将DEM数据取整对提取河网的影响,提出了首先对DEM栅格高程进行放大,然后再取整的方法.以长台关流域为例,将直接对DEM数据取整和先放大后取整2种情况下提取的河网与由原始DEM提取的河网的对比分析结果为:对104个河段直接取整后只有7个河段的长度是相同的,放大后取整,河段长不相同的只有30个;直接取整后只有27个河段的比降是相同的,放大后取整河段比降不相同的只有16个.采用提出的方法可以得到与原始DEM更加吻合的数字河网.
Converting floating-point DEM data directly to integer types changes the aspect and slope of some of the rasters, increasing the number of fake channels in the flat areas of the DEM and the extracted river network.In order to eliminate rounding of the DEM data to the extraction of the river Network, this paper proposes a method of amplifying and then rounding the DEM raster elevation.With the example of Chang-Tai-Kwan basin, the DEM data will be directly extracted and the first two rivers will be extracted The results of the comparison between the network and the river network extracted by the original DEM showed that only the length of the seven river sections after the 104 river sections were rounded was the same, After the direct rounding, only 27 river sections have the same drop ratio, and only 16 of them have different amplitudes after the enlargement, and the proposed digital river network is more consistent with the original DEM.