To assess the urban waterlogging mitigation effectiveness on low impact development (LID) in semi-mountainous regions, the Storm Water Management Model (SWMM) of a semi-mountainous region combined with GIS was generalized. The SWMM was calibrated and validated through maximum seeper depth of the checkpoints, and various LID scenarios have been designed according to local conditions. The discharge processes of outlets, surface runoff, peak flow and peak time were analyzed in different scenarios. The results show that: all the flow processes of outlets in the LID scenario are gentler than that in the status quo scenario, and the effectiveness of LIDs in semi-mountainous regions are different from that in plain regions because of the slope influence; in semi-mountainous regions, the LID effectiveness on surface runoff reduction decreases with the increase in rainfall return period or the extension of rainfall duration, but remains almost unchanged with the increase in rainfall peak coefficient; the LID effectiveness on control peak flow reduction is not remarkable with the change in rainfall characteristics, and the LID effectiveness on peak time delay is poor. This research can provide decision support for regional small-scale measures of urban waterlogging mitigation and reduction in semi-mountainous regions.

为了评估半山区低城市发展对低洪涝灾害的缓解效果，对半山区结合GIS的雨水管理模型（SWMM）进行了概括。通过检查点的最大渗透深度对SWMM进行了校准和验证，并且根据当地条件设计了各种LID方案。分析了不同情况下出口的排放过程，地表径流，峰值流量和峰值时间。结果表明：LID情景下网点的所有流动过程都比现状情景下要平缓，并且由于坡度的影响，半山区的LID的有效性与平原地区的不同。在半山区，LID对地表径流减少的有效性随降雨返回期的增加或降雨持续时间的延长而降低，但随着降雨峰值系数的增加而保持几乎不变。降雨特征的变化对控制峰值流量减少的LID效果不明显，对峰值延时的LID效果较差。该研究可为半山区减少和减少城市涝灾的区域性小规模措施提供决策支持。