The Importance Estimation Of Evaluation Index In Sponge City Construction Level Based On Set Pair Analysis

The higher increasing of the urbanization rate,the more prominent of urban contradictions.What’s more,the “city disease” problems such as rainstorm water logging,black and odorous water,and water shortages urgently need rectification.In 2013,the construction of sponge cities was proposed;in 2014,Sponge City Development Technical Guide has been issued.In 2015,the government has carried out The Guiding Opinions on Promoting the Construction of Sponge City and The Performance Evaluation and Evaluation of Sponge City Construction,and the first 16 pilot cities were set up nationwide.In 2016,the norms related to sponge cities have been incorporated into the concept of sponge city construction,and the second batch of 14 pilot cities have been established.In 2017,National "two sessions" proposed to further strengthen the construction of sponge city,and The China Construction News created a special issue of China Construction News and China Sponge City to better guide the sustainable development of sponge cities.Based on systematic analysis and comprehensive summary of the relevant index system,this article combines connotation,goals,with approaches of construction of the Sponge City to conduct researches on the Sponge City Construction Evaluation from theory and practice.Firstly,based on analysis the connotation,goals,and construction approaches of construction of the sponge city,and relevant evaluation criteria.the evaluation index system for sponge-city construction level was established from six aspects of water ecology,water environment,water resources,water security,water management,and water culture.Using the theory analysis method and work breakdown structure method to systematically identify the factors influencing the evaluation of sponge city construction.Secondly,this paper discusses the set pair analysis method by applying it to the importance estimation of evaluation index in sponge city construction level.It is proposed to use a method of combining the interval analysis method and the set pair analysis method to determine the weight indicators,and sort indicator factors.It can be known from the weight of the criteria level that the construction of a sponge city should be focused on the construction of water environment.According to the index layer weight under each indicator layer,as we can see that for aquatic ecology,we should restore ecological shoreline and aquatic biodiversity;in terms of water environment,we should reduce the number of spillovers from confluent overflows and increase the cutoff of early rainwater in the diversion system;in terms of water resources,the per capita available water resources are increased;in terms of water security,the number of days during which storms occur is reduced;in terms of water management,the government is required to implement relevant policies and regulations;and for water culture,public satisfaction of local water landscape needs to be improved.The weights of comprehensive indicators should focus on the reduction of the number of spillovers from confluent overflows in “water environment”,the restoration of ecological shorelines in “water ecology” and the control days of urban rainstorms in “water security”.Finally,using the extension theory and set pair theory to determine the level of the evaluation index of the construction level of the sponge City,from the proportion of the standard level,the current construction of sponge cities should focus on the construction of water environment.As for water ecology,we should pay more attention to the restoration of aquatic biodiversity;in terms of the water environment,we should pay more attention to reduce the overflow number of confluence spillway;in terms of water safety,we should pay more attention to reduce the number of urban rainstorm and waterlogging days;for the part of water management,we should focus on the proportion of investment in the construction of the sponge city;in terms of water resources,we should pay more attention to increasing the amount of per capita available water resources;In terms of water culture,we should pay attention to the popularity of heavy water culture and education.The construction level index system belongs to the uncertainty of the same situation,and the uncertainty is obvious,it shows that the index system of the index system will change dynamically with the construction stage of the sponge City,which indirectly indicates the selection of the index system is reasonable.The two methods above are used to determine the importance of the evaluation index of the construction level of the sponge city.As a whole,the water environment in the construction of the sponge city should be the same.At the same time,the emphasis on the construction of water environment,water safety,water resources and water ecology respectively should be the same,which indicates that the weighting indicators of the index system is reasonable.