上海滨海盐碱地区雨水花园适应性结构设计——以临港海绵城市建设示范区为例

Adaptive structure design of rain garden in coastal saline alkali area of Shanghai——Take Lingang sponge city demonstration area as an example

上海临港新城作为我国海绵城市示范点之一,其所在地上海属于典型的滨海盐碱地区,但现有海绵城市建设中关于雨水花园的设计缺乏对地下水位高、土壤盐碱化严重等问题的解决方案。针对以上问题,将雨水花园与工程隔盐技术相结合,通过室内模拟和正交试验方法,研究不同结构雨水花园(包括隔盐层材料、隔盐层位置、填料层厚度)对隔盐效果和雨水渗透过程的影响。结果表明,不同因素对隔盐效果影响大小的顺序为:隔盐层材料>填料层厚度>隔盐层位置;对雨水渗透影响大小的顺序为:隔盐层材料>隔盐层位置>填料层厚度。并且根据盐碱地等级分类和水文功能需求,提出适于上海滨海盐碱地区的3种雨水花园结构模式:适用于重度盐碱地区的强隔盐型雨水花园、中度盐碱地区的综合型雨水花园和轻度盐碱地区的渗透型雨水花园。

Shanghai Lingang New City,one of the demonstration sites of sponge city,is a typical coastal saline-alkali area.Currently,the design of existing rain garden lacks solutions to the problems of high groundwater level and soil salinization.In order to solve the above problems,we use the indoor simulation experiment and orthogonal experiment to analyze the effect of salt isolation and rain infiltration impacted by different structures(salt-insulated layer material,salt-insulated layer position,filler layer thickness).The results show that the order of different factors affecting the effect of salt isolation is:salt-insulated material>filler layer thickness>salt-insulated layer position.The order of impact on rain infiltration is:salt-insulated material>salt-insulated layer location>filler layer thickness.According to the classification of saline-alkali land and the requirement of hydrological function,three types of rain garden structures are proposed.The first is strong salt-insulated rain garden suitable for severe saline-alkali areas.The second is suitable for the comprehensive rain garden in the moderate saline-alkali area.The third is suitable for the permeable rain garden in the light saline-alkali area.