常德市海绵城市建设地质条件适宜性评价研究

Research on suitability evaluation of geological conditions for the construction of sponge city in Changde City

海绵城市建设过程中,根据城市所处区域的地形地貌、地质条件等特点,选择适宜的海绵城市设施类型是其关键问题之一。本研究以常德市规划区为研究对象,在广泛收集和分析研究区有关地质、水文地质资料的基础上对海绵城市建设影响因素进行分析,并建立指标评价体系;选择7个影响因子作为海绵城市建设地质适宜性评价指标,利用层次分析法对各影响因子进行权重赋值;在对各影响因子分级评分的基础上,利用MAPGIS按照建立的指标评价体系进行加权叠加评分,根据评分结果选择海绵城市雨水管理的适宜设施。研究表明:地质条件对大气降水的入渗、径流、地表水与地下水相互转换以及地下水存储条件等有着重要影响。这都是海绵城市建设需要重点考虑的方向,因此,低影响开发(LID)工程设施的类型和建设方案,需要充分结合该地区的地质条件进行设计。而且在影响海绵城市建设的地质条件因素中,包气带渗透性能和包气带厚度两者所占权重最大,因此重要程度最高,需要优先考虑。

During the construction of a sponge city,according to the topography and geological conditions of the area where the city is located,selecting the appropriate type of sponge city facilities is one of its key issues.This study takes the planning area of Changde City as the research object,analyzes the influence factors of sponge city construction on the basis of extensive collection and analysis of relevant geological and hydrogeological data in the research area,and establishes an index evaluation system;select 7 influencing factors as sponge cities Construct geological suitability evaluation indicators,and use the analytic hierarchy process to assign weights to each influencing factor;on the basis of grading and scoring each influencing factor,use MAPGIS to perform weighted and superimposed scoring according to the established indicator evaluation system,and select sponge city rainwater based on the score Appropriate facilities for management.Studies have shown that:Geological conditions have important influence on infiltration and runoff of atmospheric precipitation,conversion between surface water and groundwater,and storage conditions of groundwater.These are the key directions for sponge city construction.Therefore,the types and construction schemes of LID engineering facilities need to be designed in full consideration of the geological conditions in this area.Moreover,among the geological conditions affecting the construction of sponge city,the permeability of vadose zone and the thickness of vadose zone have the greatest weight,so they are of the highest importance and need to be given priority.