房地产项目建设会形成4种不同类型的下垫面：不透水建筑物屋顶、硬化地面、透水型地面和绿地。国家相关标准与规范确定，四种下垫面面积占总面积的比重分别为24%、22.8%、28.2%、25%，据此对各自径流系数加权平均得出北京市房地产项目建设形成的下垫面的总的径流系数为0.60。同时对2006年-2011年6年间北京市的房地产项目的雨水径流量进行计算分析，结果表明，北京市房地产项目7、8月份产流量最大；四种下垫面形成的雨水径流量顺序为：不透水建筑物屋顶>硬化地面>透水型地面>绿地。基于对房地产项目特点及其雨水径流特征考虑，房地产项目建设过程中，应注重透水铺装、集雨池、屋顶绿化和下凹式绿地等雨水收集与利用措施建设，加大雨水入渗与利用，缓解城市雨水管道排水压力。

The underlying surface, which is formed by the real estate construction, is divided into four types: waterproof building roof, indurative ground, pervious ground and greenbelt. On the basis of the national standards and regulations, four underlying surface area of ??proportion of the total area is 24%, 22.8%, 28.2%, 25%. By calculated, the total runoff coefficient of the Beijing real estate project construction is 0.60. The calculation and analysis of the rain runoff from building area in Beijing from 2006 to 2011 show that the rain runoff become maximum in July and August .The order of the rain runoff formed by four underlying surface was: waterproof building roof, indurative ground, pervious ground, greenbelt. Based on the analysis of the characteristics of building area and the features of rainwater runoff, we should pay attention to the measures construction of rainwater collection and utilization to increase rain infiltration and utilization and alleviate the pressure of urban rainwater pipe drainage, such as permeable pavement, catchment basin, roof greening and undercut type green space.

宁夏生产建设项目水土流失防治技术研究