Study On Construction And Application Of Quality And Efficiency Evaluation Model For Rainwater And Sewage Diversion Project Based On AHP-fuzzy Comprehensive Evaluation Method

Rainwater and sewage diversion means that rainwater is discharged into river directly and sewage is sent to sewage treatment plant through independent pipeline respectively.Carrying out rainwater and sewage diversion project is very important to alleviate urban rainwater overflow pollution,eliminate black and odorous water bodies and improve the treatment efficiency of sewage treatment plants.But there are many reasons leading to the invalidation of rainwater and sewage diversion project.For example,the pipe material and construction quality are not controlled strictly and some residents have poor drainage habits.In order to ensure the function of rainwater and sewage diversion project,it is urgent to conduct an evaluation model to evaluate the quality and effectiveness of rainwater and sewage diversion project.The evaluation model of rainwater and sewage diversion project is constructed based on analytic hierarchy process(AHP)and fuzzy comprehensive evaluation theory for residential area and enterprise respectively and it is verified by taking zone A and B as the study cases.Specific research results are as follows:1.Establishment of the index system and index scoring methodTaking the construction management documents,water quality of nodal wells and maintenance of drainage facilities as criteria,16 indicators and 7 indicators are selected to construct the evaluation index system for residential area and enterprise repectively and the scoring method of each indicator is determined.2.Calculation of index proportion and establishment of evaluation modelAHP is used to calculate the index proportions.The evaluation results are divided into five grades: unqualified,qualified,medium,good and excellent.Semi-trapezoidal function is used to determine the membership degree of each grade,and the final evaluation grade is determined according to the principle of maximum membership degree.3.Application research of the evaluation modelZone A and B are choosed to be evaluated on behalf of the residential area and enterprise respectively.Unqualified,qualified,medium,good and excellent districts accounted for 11.54,1.54,7.69,7.69 and 71.54% in zone A and 8.51,6.38,8.51,6.38 and 70.22% in zone B.The unqualified areas are investigated and the phenomena of illicit connection and groundwater infiltration are common.The existing problems of rainwater and sewage diversion project are summarized and the suggestions for rectification are put forward in this article.The evaluation model has strong significance for the construction of rainwater and sewage diversion project.