ABSTRACT

Reducing imperviousness connectivity by low impact developments or receiving pervious area (RPA) has been a regular strategy for runoff mitigation. However, the effects of RPA properties in combination with imperviousness connectivity on runoff have not been fully discussed. In this study, two kinds of RPA are defined according to ponding volume: retention-dominated and conveyance-dominated. Runoff for a small urban catchment was evaluated under scenarios with varying imperviousness connectivity, rainfall condition and initial soil saturation by the Storm Water Management Model. The results present significant runoff mitigation for imperviousness disconnecting by the retention-dominated RPA. However, imperviousness disconnecting by the conveyance-dominated RPA may conversely lead to higher peak runoff. Increased initial soil saturation weakens the effectiveness of runoff mitigation for the retention-dominated RPA, but has limited effects for the conveyance-dominated RPA. This study emphasizes the role of RPA properties in addition to indicators evaluating imperviousness only in urban planning.

摘要

通过低影响开发或接收渗透区 (RPA) 来减少不透水连通性一直是径流缓解的常规策略。然而，RPA 特性与不透水连通性对径流的影响尚未得到充分讨论。在本研究中，根据积水量定义了两种 RPA：保留主导型和输送主导型。通过雨水管理模型，在具有不同不透水连通性、降雨条件和初始土壤饱和度的情景下评估了小型城市集水区的径流。结果表明，滞留主导的 RPA 对不透水断开的径流有显着的缓解。然而，由运输主导的 RPA 断开不渗透性可能会反过来导致更高的峰值径流。增加的初始土壤饱和度削弱了以滞留为主的 RPA 的径流减缓效果，但对以运输为主的 RPA 的影响有限。除了仅在城市规划中评估不透水性的指标之外，本研究还强调 RPA 属性的作用。