海绵城市地质适宜性分区研究——以宿迁市区为例

Study on geological suitability zoning of sponge city——Take Suqian as an example

地质条件对海绵城市建设具有重要影响。本次研究以宿迁市区为对象,在充分收集和整理宿迁城市地质调查数据基础上,分析影响海绵城市建设的地质要素。分析地质条件的渗水、蓄水、净水潜力,选取地表坡度、包气带渗透系数、城镇密集程度、潜水水位埋深、潜水渗透系数、浅层含水层富水性、天然防污性能、表层土壤污染程度8个指标建立评价体系;利用层次分析法(AHP)计算各指标权重,并对各单指标进行分级评分;借助mapgis软件对各指标数据进行叠加分析,最终实现宿迁市区海绵城市建设地质适宜性分区,并给出适宜宿迁市区海绵城市建设的LID设施类型。研究表明:包气带渗透系数、潜水位埋深及潜水渗透系数是影响宿迁市海绵城市建设中重要因素。宿迁市区海绵城市建设分为Ⅰ、Ⅱ、Ⅲ、Ⅳ共4级,Ⅰ级占全区面积16%;Ⅱ级占全区9%;Ⅲ级占全区57%;Ⅳ级占全区18%。Ⅰ级区选择强入渗型LID设施;Ⅱ级区选择适宜雨水入渗型为主的LID设施;Ⅲ级适宜入渗能力较小LID设施与调节类设施及传输类设施的组合;Ⅳ级区应重点建设雨水集蓄类的LID设施类型。

Geological conditions have an important influence on construction of sponge city.Based on the urban area of Suqian,Geological factors that influence the construction of sponge city is analyzed through processing of the urban geological survey data.According to the potentiality of water seepage,storage and purification,eight factors,including surface slope,permeability coefficient of aeration zone,urban density,Buried depth of potential water level,Permeability coefficient of potential water,Water yield of shallow aquifer,intrinsic vulnerability,Pollution degree of surface soil,are chosen to build the evaluation systems,AHP method was used to assign the weight of evaluation index,than grade each single index,and MapGis was used to carry out the weighted superposition of two,finally realizing the geological suitability zoning of sponge city construction in Suqianand then give the LID facilities types suitable for the urban area of Suqian.The result show that Permeability coefficient of aeration zone,buried depth of potential water and permeability coefficient of potential water are important factors influencing the construction of Suqian sponge city.The construction of sponge city in Suqian City is divided into four levels,Ⅰ,Ⅱ,Ⅲ and Ⅳ,with level Ⅰ accounting for 16 % of the whole area,level Ⅱ Accounting for 9 %,level Ⅲ Accounting for 57 % and level Ⅳ Accounting for 18 % of the whole area.In class Ⅰ area,the strong infiltration type of lid facilities shall be selected;in class Ⅱ area,the suitable rainwater infiltration type of lid facilities shall be selected;in class Ⅲ area,the combination of lid facilities with small infiltration capacity,regulation facilities and transmission facilities shall be selected;in class Ⅳ area,the rainwater collection and storage type of lid facilities shall be focused.