Rational Allocation Of Economic Water And Ecological Water For River Health In The Weihe River

Water resources are the core of sustainable development.With the rapid development of society and economy,water consumption has shown an ever-increasing development trend.Water scarcity has become one of the limiting factors for sustainable development.The Weihe River is hailed as the mother river in the Guanzhong area of Shanxi Province.However,in recent years,the water volume of the Weihe River has been significantly reduced,and the development potential of traditional water resources in the region has also been limited.This has brought challenges to the sustainable development of the Guanzhong region.The rational allocation of water resources is considered to be an effective way to solve water scarcity.However,the connotation of rational allocation of modern water resources has shifted from the traditional development and utilization of water resources,which is mainly based on economic benefits,to the development and utilization of water resources oriented to the natural and ecological needs.At the same time,it also comprehensively considers the economic,social and ecological benefits of water resources,and takes into account the four-in-one needs of the complex systems of society,economy,resources,and the environment.This article will use the method of system analysis,using the system dynamics simulation model to systematically study the relationship between water resources-social economy-ecological environment,and take the Guanzhong area as an example to explore the reasonable allocation of economic water and ecological water.The main findings are as follows:(1)Based on the concept of river health,the connotation and importance of river health were analyzed,and the evaluation indicators of river health in the Weihe River were put forward.According to the ecological functions of rivers,three types of ecological water use schemes were classified.Combining with the actual conditions in the Guanzhong area of the Weihe River Basin,through the analysis of different environmental flow calculation methods,the advantages and disadvantages of various research methods are compared.Then,according to the requirements of different river ecological functions,the set values of the environmental flow required to maintain the ecological base flow,self-purification volume,and sediment volume of the health of the rivers in the rivers are 16.00×10~8m~3,29.3×10~8m~3,and 60.89×10~8m~3,respectively.(2)A method of systematic analysis was used to establish a model for the rational allocation of water consumption and ecological water use in the Guanzhong area of the Weihe River Basin.The ecological water and economic water were used together to allocate water,and ecological water was given higher priority.The model takes the balance of water supply and demand as the core and comprehensively considers the three aspects of water resources,social economy and ecological environment.The system is divided into 7subsystems and contains a total of 162 variables.At the same time,using Vensim software,the stock and flow diagram was drawn,and the model was tested for validity and error.The results showed that the error of most parameters did not exceed 10%,MARE was 0.018 and0.055,and the model had good reliability.(3)Through the use of the allocation model for the economic and ecological water use in the Guanzhong area of the Weihe River Basin,the simulation of the current 40-year socioeconomic development,water resources allocation,and water balance of supply and demand will be simulated.According to the simulation results,under the two configurations of ecological basic flow and self-purification water demand,the ecological water and economic water can maintain coordination,and the water balance reaches 30.39×10~8m~3 and17.09×10~8m~3,respectively.Considering that the sediment allocation plan reached the limit of-10.41×10~8m~3 in the later stage of the simulation,it is predicted that Guanzhong region will face the risk of water scarcity in 2055,which will have a negative impact on social and economic development.At the same time,under the current development model,the water allocations for the three environmental flow plans all show unsustainable characteristics.There are certain problems in the sustainable use of water resources.(4)A set of comparative scenarios and four alternative development scenarios were set up through scenario analysis.The simulation results show that the implementation of the water diversion project provides an annual water supply of 27.5×10~8m~3 in the Guanzhong water-receiving area,which effectively improves the carrying capacity of the water resources in the Guanzhong region and can guarantee Guanzhong's development needs for the next 20 years.Each supplement of 1.35×10~8m~3 of water resources under the current development model can support the development needs of Guanzhong within the next year.In addition,in the alternative development scenarios,the economic water use and ecological water allocation under the three environmental flow plans of the current development pattern and the low development pattern all show unsustainable characteristics.This unsustainability has been contained under the medium development pattern,and the high development pattern can better promote the sustainable use of water resources and realize the rational allocation of economic water and ecological water.(5)Based on the results of scenario simulation analysis,adaptive measures for sustainable development in the Guanzhong region should mainly rely on the improvement of technical measures.Only a more efficient water use efficiency,low wastewater discharge rate,higher wastewater treatment rate,and water reuse rate are the long-term solutions for promoting rational allocation of economic and ecological water use.Secondly,formulating reasonable development goals and strengthening water resources planning and management also have positive effects on promoting the coordinated development of economic and ecological water.In addition,the Guanzhong region needs to focus on the protection of the ecological environment during the development of water resources,and at the same time strengthen the development and utilization of non-traditional water resources.