永续洪水滞流池地表及地下系统

Sustainable surface-subsurface storm water retention system

近年来运用最佳都市排水管理实践(Best Management Practices or BMPs)开发出许多新排水系统设计方法并开始广泛应用,例如使用高透水率的路面都市绿带、干井、渗透式集水池、沟渠、湿地以及滞流池等。这些设施均具有有效的滞流功能。多年来,不当积水、延长排水和下水道堵塞等,造成了一些都市排水的失败。事实证明,许多问题的产生常常是因为滞流池设计方法只考虑地表水文学而忽略地下水层的种种因素。结果,当地下水层渗流无法接纳表面渗透时,导至整个滞流系统无法良好运作。本文提出一个新概念,在设计洪水滞流池时,应考虑地表水文及地下水文对系统运作的影响,并通过3个实例说明了设计滞流池容量、几何形状及其永续运作的持续力的计算方法。

The concept of Storm-water Best Management Practices （BMP＇ s） has begun to alter the designs of urban storm water systems. For instance, on-site permeable pavement, vegetal beds, rock-filled trench, open ditch, infiltrating basin, percolation basin, wetland, retention and dry wells detention have been adopted as effective measures. Over the years, some failures have caused standing waters, prolonged draining process and frequent clogging etc. Many of these problems were induced by the fact that the current design approach of storm water storage systems only focuses on surface hydrology and ignores the subsurface constraints. As a result, when the subsurface seepage rate cannot sustain the surface infiltrating rate, the system fails to function well. This paper presents a new concept to combine subsurface and surface requirements into storm water basin designs. Three examples are used to illustrate the method of calculating basin storage volume and basin geometry of retention basin and its sustainability of long-term operation.