中文摘要：

城市下垫面土地利用格局与地形的复杂性将导致地表汇流模式的多变性。在城市雨洪管理模型中，不同汇流模式的选取对雨洪模拟结果产生重要影响，而这一影响往往被忽视。基于设定与巴中城市社区尺度相近的实验区以及巴中市的真实降水数据，并根据实验区土地利用格局特征，在SWMM雨洪管理模型汇水模块中设置Outlet、Impervious、Pervious 3种汇流演算模式及其演算面积比，分析了不同土地利用格局响应下的不同汇流模式选择对城市雨洪模拟结果的影响。结果表明：（1）Outlet、Impervious两种汇流演算模式下汇水区地表径流的模拟结果相同，但与Pervious演算模式下的模拟结果差异显著。在Pervious模式下地表径流相对另外两种汇流模式最大降低了52%，降雨下渗量提高了近1倍。（2）在Pervious模式下，演算面积比对汇水区地表径流模拟结果具有重要影响。在总不透水面（IA）面积一定的情况下，有效不透水面（DCIA）的减少引起非有效不透水面（UIA）的比率增加。这种土地利用格局的变化致使汇水区总径流量、径流系数显著下降，降雨下渗量逐渐增加，洪峰流量则呈先增后减的趋势，且在非有效不透水面（UIA）比率为30%和40%时（此时非有效不透水面与渗透面面积相接近），洪峰流量最小。对结果的分析表明了雨洪管理模型在小尺度汇水区上应用时，应根据土地利用格局特征选择相应的地表汇流模式。正确的评价和分析不同土地利用格局方案对地表径流的影响，从而更为科学地指导城市雨洪管理和海绵城市的规划与建设。

英文摘要：

he patterns and topographic complexity inherent in urban surfaces cause considerable variations in flow paths, and may influence the simulation outputs of urban stormwater management models （SWMMs）. However, the influence of these variables in urban storm water management is largely unknown and so it is usually ignored, consequently reducing the accuracy of the simulation results. To examine how patterns of land use and overland flow routing options influence the simulation outputs of the SWMM, we chose an experimental site in Bazhong City. We developed three sub-area overland flow routing methods （outlet, impervious, permeable） for different precipitation intensities and land use patterns within the sub-catchment area module of the SWMM, and compared the simulation outputs. The results indicated that the simulated surface runoff for the outlet and impervious routing methods were the same, but were considerably different from those for the permeable routing method. Under the permeable routing method, the surface runoff decreased by 52% and the amount of rainfall that permeated almost doubled. The percentage of runoff routed by the permeable routing method had a significant impact on the simulation results. As the percentage of routed runoff increased, the directly connected impervious area （DCIA） gradually decreased and the unconnected impervious area （UIA） gradually increased, which led to a considerable reduction in the total runoff volume and a decrease in the surface runoff coefficient. Simultaneously, the amount of rainfall that permeated gradually increased, but the peak flow rate initially increased and then decreased. When the percentage of routed runoff reached 30% or 40%, the UIA was nearly equal to the permeable surface area, and the peak flow rate was at a minimum. The results from the present study showed that land use patterns and overland flow routing options influenced the SWMM simulation outputs. The results also suggest that for the effective management of urban stormwater, urban