关于城市防洪、治涝、排水标准的探讨

A Discussion of Urban Flood Control, Waterlogging Control and Drainage Standards

城市防洪、治涝、排水标准的拟定涉及不同行业和不同规范,往往不能协调统一,这就要求在相关工程实践中,对不同研究对象及其相互之间的协调关系进行精细研究。本文对现行规范和政策进行了解读,分析了城市设防标准与城市河道设防标准的关系,建议防洪河道的标准可与城市防洪标准一致,排涝河道的标准可低于城市内涝防治标准。讨论不同对象淹没时间的要求,建议按城市和农田分别划定。分析河道与河道之间、河道与管渠之间水位的衔接方法,建议不同河道、同一河道不同河段按同频率进行衔接,有顶托的情况以高水位作为边界条件。讨论河道与管渠之间水位的衔接方法,建议管渠在发生设计标准内的暴雨时,按无压流过流,衔接河道2~5年设计水位;在内涝防治标准时按压力流过流,此时与河道水位之间的关系建议用数学模型研究。探讨了在内涝和排水时设计暴雨的选用方法,以《深圳市排水(雨水)防涝综合规划》为例,建议用年最大值法计算设计暴雨,并采用同频率分析法编制不同历时不同频率的设计雨型,当进行城市内涝评估时,选用长历时雨型,当计算雨水管渠时,选用短历时雨型。

When determining the urban flood control, waterlogging control and drainage standards involves different industries and specifications, which often cannot be unified. This requires careful research on different objects and their relationships in relevant engineering practices. This paper interprets the current specifications and policies, analyzes the relationship between urban fortification standards and urban river channel fortification standards, and suggests that the standards of flood control rivers should be consistent with urban flood control standards, and the standards of waterlogging drainage rivers could be lower than urban waterlogging control standards. This paper discusses the requirements for flooding time of different objects, and it is suggested to divide them according to city and farmland. It analyzes the connection method of water level between river courses and between river courses and pipe channels, suggests that different river courses and different river sections of the same river course be considered at same standard, and high water level as boundary condition when there is water level jacking, and discusses the connection method of water level between river channel and pipe channel. It is suggested that the pipe channel should flow without pressure, and the design water level of the connecting river channel should be 2~5 years standard. In the standard of waterlogging control, the pipeline is pressure flow, and suggested to be studied with a mathematical model. The method of design rainstorm in waterlogging and drainage is discussed. Taking the Comprehensive Planning for Drainage and Waterlogging Prevention in Shenzhen as an example, it is suggested that the annual maximum method be used to calculate the design rainstorm, and the same frequency analysis method be used to compile the design rain patterns with different durations and different frequencies. When evaluating urban waterlogging, the long duration rain pattern is selected, and when calculating pipes, the short duration rain pattern is selected.