基于Copula方法的城市排水排涝设计标准协调性研究

Research on the Coordination of the Urban Drainage System and Sewage System Design Standards Based on Copula Method

我国排水系统和排涝系统分属不同部门管理,遵循不同设计规范,缺乏统一的标准衔接方法。为解决排水排涝系统设计标准不衔接造成的潜在内涝风险和投资浪费问题,研究以中山和珠海市为研究对象,基于Copula方法和最可能设计组合构建了排水排涝设计标准的衔接方法,计算了不同Kendall重现期条件下的最可能排水排涝设计降水量组合。结果表明,Copula理论可有效构建不同时段长降水序列的联合分布,Copula理论分布与经验分布之间拟合良好;以中山市主城区为例,排水排涝系统最可能设计降雨量组合结果表明,原排水系统设计规模偏小,原排涝系统设计规模偏大,据此可针对原规划方案进行科学调整。

The urban sewage system and drainage system belongs to different departments in China,which adopt different design codes dur⁃ing designing processes and thus lack coordination in design combinations.In order to avoid potential waterlogging risk and over-investment,this research takes Zhongshan and Zhuhai as study areas and develops a design combination selection method of urban sewage and drainage systems based on Copula Theory and Most-Likely Estimation(MLE)Method.The MLE design combinations with different Kendall’s return periods are obtained thereafter.Results show that joint distributions between precipitation series with different kinds of duration can be effec⁃tively constructed with good fitting effects of Copula theoretical probabilities and empirical probabilities.The MLE design combinations ob⁃tained in this research revealed that the raw design scale of sewage system is underestimated while the design scale of drainage system is over⁃estimated for the downtown area of Zhongshan City,which provide scientific references for adjusting the design scheme of sewage and drain⁃age systems.