Research On Optimal Regulation And Control Of Water Resources Carrying Capacity In Chengdu

With the release of the most stringent water resources management system in Chengdu,and the determination of the "three red lines" total water consumption control targets in all administrative regions of Chengdu,the Chengdu Municipal Committee of the Communist Party of China proposed "East advancement,south expansion,west control,north reform,and central "Excellent" urban spatial development strategy,the economic and social development of relevant regions will be rapid by then,and Chengdu will face huge challenges to water resources in the future.This research aims at the contradiction between the supply and demand of water resources in mega-cities,and takes various administrative regions of Chengdu,Sichuan Province as the research object.The entropy TOPSIS method is used to evaluate the water resources carrying capacity of each administrative region and explore the impact of different policies on the water resources carrying capacity of each administrative region;By constructing a prediction model of water resources carrying capacity based on system dynamics,the future development trend of water resources in various administrative regions of Chengdu is studied;finally,combined with the research results,policy recommendations are made for the rational use and planning of future water resources in the study area.The main content and results of this research are as follows:(1)Based on the idea of sustainable development,combined with the actual situation of the study area,an evaluation index system for each administrative region in Chengdu was constructed.After the normalization of each index,the weight of each index was determined by the entropy weight method,and then the TOPSIS method was used to the data of various indicators are calculated,and finally the water resources carrying capacity index of each administrative region from 2000 to 2018 is obtained.Through the visual analysis of the calculation results in time and space,it is found that policy changes will have a significant impact on the evaluation results of water resources carrying capacity in the study area.(2)Based on the theory of water resources carrying capacity and system dynamics,the system dynamics simulation software Vensim was used to establish a prediction model of water resources carrying capacity in various administrative districts of Chengdu.The model was verified with historical data from 2000 to 2018,and the results showed the relative error between historical data and model simulation results is within 10%.The results of sensitivity analysis on the model also show that the constructed model is effective.(3)Based on the future urban spatial development strategy of different regions of Chengdu,five different control schemes have been designed to simulate the development trend of water resources carrying capacity from 2019 to 2035.The results of the benchmark control plan show that the water resources carrying capacity index of all administrative regions in Chengdu is in a downward trend.With the exception of Dujiangyan City,the water resources carrying levels of the remaining 14 administrative regions have all dropped to critical and overloaded levels.Among them,Qingbaijiang District has the largest decline,which is lower than the baseline.A decrease of 38.76% in 2018 indicates that the current development model cannot meet the needs of sustainable urban development;although the economic priority adjustment plan can enable rapid economic growth in various administrative regions,water resources in each administrative region have been severely damaged,and some administrative regions in the east have dropped from the critical level at the overload level,the western region has dropped from the carrying level to the critical level.The water resources carrying capacity index of Xinjin District has dropped the most,down59.22% from the base year;the industrial structure adjustment and control program can improve the utilization of water resources in the economic and industrial sectors of various administrative regions,but the improvement effect is not obvious enough,and it will take a long time to return to a bearable state.The results show that although the carrying capacity index of the eastern and southern regions has increased,it is still at a critical level.Most administrative regions in the western region have slowly risen from the critical level in the base year to the critical level.At the weak carrying capacity level,the water resources carrying capacity index of Pujiang County has a relatively large increase,up by 17.57%respectively from the base year;the resource saving control plan can greatly increase the water resources carrying capacity index of each administrative area during the forecast period,and it is predicted to In 2035,the water resources carrying capacity of all administrative regions will rise to the weakly bearable level.Among them,the water resources carrying capacity index of Qingbaijiang District has the largest increase,which is an increase of 60.91% from the base year,but the economic development of each administrative region has not reached the lowest level of social development.It is required that the future per capita GDP of multiple administrative regions is lower than the future development goals;the balanced development plan has significantly improved the future water resources carrying capacity of the study area.Each administrative region will reach the weak carrying capacity or above by 2035,and some administrative regions even reach the carrying capacity.Among them,the water resources carrying capacity index of Qingbaijiang District has increased the most significantly,an increase of 65.57% compared with the base year.At the same time,the economy of all administrative regions in the future can reach the development goals.