房山区位于北京市西南部,华北平原与太行山脉交界地带,总面积2019km2,西北部为山区,东南部为平原,以100m等高线为界,山区面积1327.2km2,占全区总面积的65.7%。由于山高坡陡,沟道纵坡大,加之土石山区植被差,遇暴雨极易产生洪水。据初步估算,山区洪水资源量约占山区降水总量的40%以上。因此,房山区洪水资源化对充分利用洪水资源、保护地下水资源、维系地域 Fangshan District is located in the southwest of Beijing, at the junction of North China Plain and Taihang Mountains with a total area of ​​2019km2. The northwestern part is mountainous and the southeast is plain. The 100m contour line is bounded by the mountainous area of ​​1327.2km2, accounting for 65.7% of the total area %. Due to the steep mountain slope, channel longitudinal slope, combined with poor vegetation in mountainous areas, in case of heavy rain can easily produce floods. According to preliminary estimates, the amount of flood resources in mountainous areas accounts for more than 40% of the total rainfall in mountainous areas. Therefore, Fangshan District, the flood of resources to make full use of flood resources, protect groundwater resources, maintain the region