Research On The Application Of AHP And MIKE Models In Sponge City Reconstruction

With the increase in urbanization rate and the rapid development of urban modernization,some cities in our country have placed too much emphasis on surface buildings during the construction phase,while neglecting the construction of corresponding green facilities and supporting municipal facilities,resulting in frequent flooding disasters in cities during heavy rains.Subsequently,the concept of sponge city construction was put forward in our country and quickly became a national strategy,but many problems were exposed during the implementation process: for example,areas with better municipal conditions were renovated,areas in urgent need of renewal were not renovated,and remodeling measures were not properly selected.The expected results are not achieved.Therefore,according to the regional characteristics,the proposed adaptive transformation plan is of great significance to ensure the smooth deployment and implementation of sponge city construction and transformation in my country and reduce the impact of urban waterlogging disasters.This paper takes Pukou District as the research object.After investigating its current conditions and reasonably dividing it,AHP is used to screen out the areas with the most transformation conditions,and then the corresponding sponge transformation measures are proposed based on the evaluation results.Finally,the MIKE simulation results are used to compare the reduction effects before and after the transformation.The main research results obtained are as follows:(1)Combining the differences in physical geography,social economy,and urban construction conditions in the study area,manually divide it into five catchment areas,use AHP evaluation method to get the most valuable catchment area for reconstruction,and find the risk of urban waterlogging The four most influential indicators are surface slope,water distribution,green area,and pipe network density.(2)Constructed a one-dimensional pipe network model,a one-dimensional river model,a two-dimensional surface overflow model,and a one-and two-dimensional coupling model of the target catchment area;constructed sunken green spaces,pipe network renovation,and river corridors based on the evaluation indicators.Repair three sponge transformation scenarios;set two rainfall scenarios with different rainfall duration and rainfall return period based on the rainfall data of the study area over the years.(3)After adding three kinds of sponge transformation measures,the cumulative speed,cumulative amount,pipe network fullness,depth of water accumulation,and retention time of water accumulation in the target catchment area have been reduced or even eliminated to varying degrees.The effect of reducing and controlling the risk of urban waterlogging has been achieved,but as the return period of rainfall increases,the total amount of runoff increases,and the effect of sponge measures has declined.(4)After comprehensively applying the three sponge transformation measures,using the depth and area of the target catchment area as indicators,it is found that rainfall within a five-year return period can effectively eliminate the risk of waterlogging,with a return period of ten or twenty years.Rainfall can greatly reduce the depth and area of stagnant water,and the result provides theoretical support for subsequent sponge city construction.