Study On Dynamic Simulation And Path Of Water Resources Optimization Allocation Considering Green GDP Growth

With the shortage of water resources and the deterioration of water environment,reducing water consumption and water pollutant emissions during economic growth,and promoting the quality of economic growth,have become inevitable choices for sustainable development of the economy,water resources and water environment.This study aims to dynamically integrate green GDP growth with water resource utilization and water environmental protection,and to construct a dynamic model of water resources optimization allocation based on green GDP growth through material flow and value creation among economic system,water resources system and water environmental system using input-output optimization methods.Taking Zaozhuang City,the node city of the east route of South-to-North Water Transfer Project and the coal-exhausted city,as an example,the optimal economic growth path,water resources allocation path and water environment improvement path under the dual control of the total amount and intensity of water resources utilization and water pollutant discharge are simulated and studied,which can provide a scientific reference for regional development planning.The main works and originalities of this study are as follows:Firstly,this study construsts a dynamic model of water resources optimization allocation considering green GDP.This study internalizes water resource costs and water environmental costs of economic growth,and simulates optimal allocation of water resources under the target of green GDP growth from a dynamic perspective,which reflects the organic unity of economic benefit,ecological benefit and resource utilization efficiency of water resources utilization,and realizes dynamic simulation of green GDP growth based on the accounting framework of green GDP indicator.Secondly,through the scenario simulation,it is found that the control of the total amount and intensity of water resources utilization and water pollutant emissions has a law of diminishing marginal utility for both economic growth and water pollutant recduction,providing a theoretical basis for scientifically setting targets of water resources utilization and water pollutant reduction.In the setting of the lower limit of annual decline rate of the intensity of water utilization,the lower limit of the annual reduction rate of the total emissions of COD and ammonia nitrogen,and the lower limit of the annual decline rate of the discharged intensity,respectively,3%,2%,and 5%,Zaozhuang City can achieve opitimal green GDP growth,water resources allocation and water pollutant reduction.Thirdly,in the optimal scenario,the paths of achieving economic growth,water resources allocation and water environment improvement in Zaozhuang City are as follows: increasing water supply and improving water structure through reclaimed water utilization;industrial restructuring,improving water efficiency and reducing pollution intensity caused by the flow of water resources elements to sectors with lower water comsumption and lower pollution;reducing the discharge of pollutants and providing the production of reclaimed water through the terminal treatment of sewage.From 2013 to 2035,the proportion of reclaimed water supply increases to 31.95%,becoming the second largest source of water supply;the output value structure of the three industries is adjusted to 0.64:36.62:62.74,and the green GDP and real GDP grow at an average annual growth rate of 5.96% and 5.88%,respectively;the intensity of water utilization decreases from 4.23 m3/thousand yuan to 1.48 m3/thousand yuan;the discharged intensity of COD and ammonia nitrogen decrease to 1.8 ton/billion yuan and 3.4 ton/billion yuan,respectively;the amounts of COD generated and discharged decrease 87.28% and 93.52%,and the amounts of ammonia nitrogen generated and discharged decrease 36.92% and 41.42%;a total of 11.64 billion yuan needs to be invested in the subsidies for terminal treatment policies.