山地城市屋面雨水可利用量分析——以重庆市沙坪坝某片区为例

为定量评估山地城市屋面雨水可利用量,以重庆市沙坪坝某片区为例,分析了重庆市的降雨特征,利用改进的径流系数法定量评估了代表年屋面雨水可利用量,并分析了降雨特征对可利用量的影响;运用设计降雨量和设计暴雨强度两个指标相结合的方法确定了蓄水池规模,使其满足径流控制率和防洪减涝的要求。研究表明:在代表年降雨量为1 198.9、1 104.4和962.7 mm时,研究区域屋面雨水可利用量分别为267 951.8、247 421.3和198 917.9 m~3,雨水利用潜力较大,降雨量对可利用量的影响较大,而降雨强度对其影响很小;研究区域蓄水池总规模为9 312 m~3,屋面径流控制率达到86.4%,为山地城市雨水利用系统中蓄水池的规模设计提供了参考依据。

Analysis of available quantity of roof rainfall in mountainous urban: a case study in Chongqing

In order to assess the available quantity of roof rainwater in mountainous urban,the paper took an urban residential district in Chongqing as the study area,analyzed the rainfall characteristics in Chongqing and utilized the improved runoff coefficient method to assess the available water of roof rainwater in typical year,and also analyzed the influence of rainfall characteristics on available water;it used the method combining design rainfall and rainstorm intensity to determine the scale of reservoir,and made which satisfy the requirements of runoff control, flood control and waterlogging reduction.The research showed that the annual collectable water of roof rainfall is 267,951.8, 247,421.3 and 198,917.9 m³ when the annual rainfall is 1198.9,1104.4 and 962.7 mm respectively.The utilization potential of rainfall resources is tremendous.The rainfall amount has greater influence on available water,while the effect of rainfall intensity on collectable rainwater is very little; the total scale of reservoir in the study area is 9,312 m³,the control rate of roof surface runoff reached 86.4%.The paper can provide reference of annual roof runoff quantity, it for the design scale of reservoir in the system of rainfall utilization at mountainous urban.