基于暴雨径流管理模型的海绵城市景观格局优化模拟

随着我国城镇化进程加快,城市不透水面积急剧增加,城市内涝问题日益严重.为此我国基于低影响开发理念提出了海绵城市概念.本研究以辽宁省沈抚新城中心城区作为研究区域,利用暴雨强度公式构建不同重现期的降雨过程,基于海绵城市理念对研究区进行景观格局优化,并运用暴雨径流管理模型模拟预规划方案和景观格局优化方案两种情景下的地表径流和雨水调控能力的差异,分析景观格局优化方案对城市地表径流和雨水调控能力的影响.结果表明: 随着降雨重现期的增大,研究区内径流总量和径流系数呈上升趋势;在相同降雨重现期下,景观格局优化方案的径流系数明显降低,径流总量的削减量逐渐增加,1年一遇、3年一遇、5年一遇和50年一遇重现期下的削减量分别为2.94、3.58、3.72、4.19 mm;相对应的削减率逐渐降低,分别为23.9%、16.4%、14.3%、9.3%;优化后的方案可满足降雨重现期p=1时设计降雨量20.8 mm、p=3时雨水管网不超载且p=50时河道不溢流的要求.

Simulation of sponge city landscape pattern optimization based on the storm water management model (SWMM)

With the rapid urbanization and increasing urban impervious areas in China, urban water-logging has become increasingly serious. The concept of sponge city was proposed based on the low impact development (LID) idea. We analyzed the impacts of landscape pattern optimization scenario on urban surface runoff and rainwater control ability in central urban area of Shen-Fu New Town in Liaoning Province. The storm intensity formula was used to construct rainfall process in different return periods. The landscape patterns of the study area were optimized based on sponge city concept. The storm water management model (SWMM) was used to simulate the differences of surface runoff and rainwater regulation ability under the pre-planning scenario and the landscape pattern optimization scenario. The results showed that total runoff and runoff coefficient of the study area were increased with increasing rainfall return period. In the same rainfall return period, the runoff coefficient was significantly reduced. The reduction of total runoff gradually increased, being 2.94, 3.58, 3.72, and 4.19 mm during the 1-year, 3-year, 5-year and 50-year return period under landscape pattern optimization scenario. The corresponding reduction rate was gradually reduced, being 23.9%, 16.4%, 14.3%, and 9.3%, respectively. Landscape pattern optimization scenario could meet the requirements that the rainfall was controlled at 20.8 mm when the rainfall return period p=1 year, the rainwater pipe network would not overload when p=3 years, and the river channel would not overflow when p=50 years.