Study On Comprehensive Benefit Evaluation Of Low Impact Development Measures In Yangguang District,Xining

With the rapid development of urbanization,the large expansion of infrastructure construction,the increasing proportion of hardened ground,the dramatic changes in the subsurface,and the weakening of the soil’s ability to capture and infiltrate stormwater are increasing the risk of urban flooding,water pollution,and caused the loss of a large amount of rainwater resources.For this reason,the concepts of low-impact development and sponge city construction have come into the public eye,and the benefits of sponge city construction are gaining increasing attention.Although sponge city construction is being carried out rapidly,there is a lack of research on the evaluation of construction effects,and a systematic evaluation system has not yet been formed,so relevant comprehensive benefit evaluation studies are still to be improved.Against the backdrop of the Sponge City concept,this study seeks to construct a comprehensive merit evaluation system that combines applicability and feasibility,with the overall benefits of LID measure construction in the community as the main line.First,by reviewing a large amount of literature,industry and local standards,and domestic and international research results,and by using methods such as expert interviews and field research,we analyzed the elements of the construction of the comprehensive benefit evaluation system of LID measures,after first selecting the basic evaluation indicators and then using the Delphi method to filter the evaluation indicators,and finally designing the overall LID evaluation indicator system in three dimensions: ecological,economic and social,and determined 15 comprehensive benefit evaluation indexes.Secondly,in order to improve the scientificity of the determination results,the weight of each evaluation index was firstly determined by the hierarchical analysis method,and then the entropy weight method was used to modify each evaluation index to obtain the relative comprehensive weight after the combination of the two methods,so as to determine the relative comprehensive weight and importance ranking of the evaluation indexes of the comprehensive benefits of LID measures.Then,a comprehensive benefit evaluation model based on fuzzy comprehensive evaluation was constructed,and the evaluation results were obtained through the operation of the weight matrix and fuzzy evaluation matrix.Finally,the comprehensive benefit evaluation was carried out for the LID measure construction project of Yangguang District,and the evaluation results were compared with the engineering reality to analyze the evaluation results and put forward suggestions to improve the comprehensive benefit.The results show that based on the fuzzy comprehensive evaluation method,the comprehensive utility of the LID measures for the construction of the sponge town in Yangguang District,Xining was 86.44,which corresponds to a comprehensive benefit evaluation rating of Ⅱ,and the construction level is "good".Among them,the evaluation value of social benefits(88.97)is the highest,followed by the evaluation value of ecological benefits(85.46),both of which belong to the level of "good" benefits;the evaluation value of economic benefits(78.27)is the lowest,which belongs to the level of "average" benefits.The evaluation results are consistent with the actual situation of the project,verifying the applicability and feasibility of the evaluation system,which can be used to evaluate the construction effect of LID measures in buildings and communities,and providing a scientific decision-making basis for the evaluation of the comprehensive benefits of LID measures.