Study On Incremental Optimization Of Municipal Water Supply And Drainage Infrastructure In Beijing

With the rapid expansion of urbanization,the upsurge of municipal infrastructure construction has lasted for over two decades in China.However,compared with developed countries,water supply and drainage infrastructure are still relatively lagging behind.Beijing’s municipal water supply and drainage infrastructure capability and discharge standards rank among the top in the country.However,the shortage of water resources in Beijing has not fundamentally changed,and the problem of urban waterlogging still exists.Therefore,it is necessary to evaluate the carrying capacity of the current water supply and drainage infrastructure construction and forecast the future water consumption demand.As for the comprehensive evaluation of urban infrastructure carrying capacity,it is necessary to establish an evaluation index system,which is divided into two categories of water supply system and drainage system.Among them,the water supply index includes the amount of water resources per capita,the length of water supply pipes per 10,000 people,the utilization rate of water supply facilities,the per capita daily water supply production capacity and the degree of leakage.The drainage indicators are the length of drainage pipes per 10,000 people,the sewage treatment rate,the utilization rate of sewage facilities,the utilization rate of reclaimed water,and the density of rainwater pipes in the built-up area.According to the standardized values of the indicators,the per capita amount of water resources in Beijing’s water supply system is far below the national average,while most of the other water supply system indicators are ahead of the national average.In the comparison of drainage system indicators,the utilization rate of recycled water leads the country,and the sewage treatment capacity is higher than the national average.Other indicators have been steadily improved since the nation’s emphasis on drainage construction,especially after 2015.The principal component analysis method is used to determine the weight of the carrying capacity index,and the result shows that Beijing’s water supply infrastructure has been higher than the national water supply infrastructure level from 2011 to 2019.The carrying capacity of Beijing’s drainage infrastructure was roughly the same as the national average before 2015.After 2015,the carrying capacity of Beijing’s drainage infrastructure has increased significantly,and the national drainage carrying capacity has maintained a steady increase.In order to determine whether the urban water supply infrastructure can meet the demand in Beijing,its future water consumption demand is predicted.According to the control target of total water consumption in 2020,the prediction of water consumption is divided into domestic water,agricultural water,ecological water and industrial water.By summing up the water consumption in various fields,the predicted value of water consumption for 2020-2025 is obtained.The total amount is controlled at about 4.2 billion cubic meters,which means that Beijing’s water supply infrastructure will basically be able to meet the capital’s water demand for some time in the future.In view of the tension of water resources in Beijing has not fundamentally changed,it is proposed to improve water reserve rationally allocate water and improve water efficiency,so as to optimize the water supply infrastructure.The carrying capacity of drainage infrastructure has been significantly improved in the past five years in Beijing.The waterlogging problem has been alleviated through the transformation of high-risk waterlogging areas.In order to explore how to comprehensively identify high-risk waterlogging areas in Beijing,for optimizing the drainage system,a prediction model for high-risk waterlogging areas is established by sorting out the location,time,disaster situation and other information of waterlogging points in recent years and related waterlogging influencing factors data,using binary logistic regression analysis.In Arc GIS,the waterlogging probability is calculated and the waterlogging probability is visualized to obtain the identification result of the risk area of waterlogging.Waterlogging risk areas can guide the optimization of drainage infrastructure in high-risk areas,using a combination of engineering measures and non-engineering measures.At the same time,sponge cities can improve the regional rainwater absorption capacity and minimize the impact of urban development and construction on the ecological environment.Finally,combining Fengtai and Fangshan’s three waterlogging point optimization cases,the optimized route of waterlogging risk is analyzed and summarized.