What Causes Waterlogging?—Explore the Urban Waterlogging Control Scheme through System Dynamics Simulation

Weike Chen,Ping Liu,Hui Dong,Chaohua Yan,Jing Dong

doi:10.3390/su13158546

Abstract

It is a common phenomenon in cities that waterlogging affects people’s normal life. It is of great significance for targeted transformation and upgrading to identify the risk factors of urban waterlogging. This paper collected the waterlogging data of Tianjin in China, analyzed the coupling mechanism among waterlogging risk factors of urban drainage systems, and then selected the system dynamics theory and the Vensim software as the analysis tools due to the mixing characteristic and the limited availability of data. After that, the sensitive factors were identified by model simulation and sensitivity analysis, and the prominent impact of urban expansion on waterlogging risk was discussed. Then, through the comparison of the three simulation scenarios, it was found that, compared with the urban development focus shifting strategy, the strategies of sponge city reconstruction and management optimization could achieve the risk control goal within a shorter time. On this basis, two kinds of governance schemes with strong operability were put forward, which were the data governance strategy and the sponge city reconstruction strategy of giving priority to old urban areas. According to the simulation results, a city can reverse the increasing trend of waterlogging risk within ten years under the appropriate scheme. Furthermore, the paper puts forward the strategic reimagining of the rural revitalization strategy and the ecological restoration strategy for the long-term sustainable development transformation of Tianjin.

Highlights

Urban waterlogging refers to the phenomenon of surface water accumulation caused by the insufficient drainage capacity of urban areas in which the runoff cannot be eliminated in time when heavy rain or continuous precipitation comes [1,2,3]
Urban waterlogging accidents were on the rise, but the growth rate was relatively slow; Among the four causes of urban waterlogging, natural risk was the most significant one, and it showed a slow growth trend year by year; The change trend of physical risk was the same as that of natural risk, but its value was relatively low; The year-on-year decrease of management risk indicated that the improvement of management level might be a feasible mean to control the growth of urban waterlogging
When the level of sponge city increased by 20%, the urban risk growth rate would change from positive 0.006 to negative 0.005, with the urban waterlogging risk turning from a rise to a fall in the 10th year

Summary

Introduction

Urban waterlogging refers to the phenomenon of surface water accumulation caused by the insufficient drainage capacity of urban areas in which the runoff cannot be eliminated in time when heavy rain or continuous precipitation comes [1,2,3]. According to 2011 data from China’s Ministry of Housing and. Urban-Rural Development, about 62% of cities, especially large and coastal ones, are facing waterlogging problems [7]. According to data from China Development and Reform. Commission, in 2017, 43 large-scale heavy rains in China caused a total of 190.99 billion. The Chinese government issued a series of policies, such as Technical Code for Urban Flooding Prevention and Control, Technical Guidelines for the Construction of Sponge Cities—Construction of Low Impact Development Rainwater

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Discussion

Conclusion