基于DEM的河网缓冲区生成方法研究

在洪水灾害危险程度区划中,需建立河网缓冲区.但是,不考虑地形影响而只按河流等级给定缓冲区宽度,则不能很好地反映实际情况.为解决这一问题,利用长江中下游的DEM和河网分布图,提出了基于DEM的河网缓冲区生成方法:利用无填洼的DEM生成流水网,进而生成子流域;挑选出河流和湖泊经过的子流域并将其进行合并,以合并后的结果作为河流和湖泊的缓冲区.结果表明,基于DEM的河网缓冲区生成方法能够生成符合实际情况的河网缓冲区.

Method for generation of river and lake buffer regions based on DEM

It is necessary to generate river and lake buffer regions in flood disaster regionalization.However,It is unreasonable to determine the range of buffer regions only based on river classification but without consideration of topographic map.For solution of the above problem,a buffer region generation method based on DEM and river and lake distribution of the middle and lower Changjiang River was put forward.In this method,DEM with no filling to steepest downslope nearby was adopted to generate the drainage network in flow direction,and further to generate the subbasin;then rivers and lakes crossing the subbasin were selected and combined to form buffer regions.The result shows that the method is effective to generate buffer regions in accordance with the reality.