Watershed unit division in Mentougou, Fangshan and Changping mountainous areas in Beijing for 23.7 extremely heavy rainstorm
From late July to early August 2023,Beijing,hit by typhoons,suffered a rare extremely heavy rainstorm in history and triggered a basin-wide catastrophic flood disaster,which caused significant losses and impacts. The falling area of extremely heavy rainstorms was mainly concentrated in the western mountainous areas,among which Mentougou,Fangshan and Changping were seriously affected. To quickly respond to the needs of post-disaster reconstruction planning,this paper proposed multi-source data such as terrain digital elevation model(DEM) based on 2 m resolution,data,digital orthophoto map(DOM),ditches,roads,and the results of the first water census in 2010. The watershed extraction method for the deep mountainous area and the shallow mountainous area was applied to the disaster-stricken areas in Beijing. The mountain watershed units of Fangshan,Mentougou,and Changping districts were demarcated. Based on the watershed unit data,the population analysis of villages and during the extremely heavy rainstorm was conducted. The experiments prove that compared with traditional hydrological model extraction algorithms,the extraction results in this paper are more consistent with the actual terrain.Compared with the results of the first water census,the reliability of this research method is verified.
watersheddigital elevation model(DEM)deep mountainous areashallow mountainous areawater census
万方数据
