Evaluation Of Water Resources Carrying Capacity In Qingjiang River Basin

Since the 19 th CPC National Congress,General Secretary Xi Jinping has repeatedly emphasized the importance of "promoting well-coordinated environmental conservation and avoiding excessive development," adhering to "ecological priority and green development," and promoting the Yangtze River economic belt’s high-quality development.All commercial activities involving the Yangtze River must be conducted in a manner that does not harm the environment,and the Yangtze River’s ecological environment can only be optimized instead of being deteriorated.And the ecological protection of water resources is the Yangtze River’s top priority.The Qingjiang River,the Yangtze River’s first major tributary after the Three Gorges and the second largest tributary to the Han River in Hubei Province,has abundant water resources and good water quality in general.However,the water resources of the Qingjiang River basin must support not only the development of Hubei Province,but also the Yangtze River,and even the entire country.According to the theory of growth limit,human society must pay attention to the problem of resource and environmental carrying capacity while pursuing economic growth.Carrying capacity is not only a scientific proposition with the significance of human limits to explore the "maximum load",but also a policy issue with great practical value for the coordinated development of population,resources.Therefore,as an innovation to comprehensively deepen reform and construct ecological civilization,the establishment of the carrying capacity monitoring and early warning mechanism is critical to the transformation of economic development mode,optimization of the spatial pattern development of the country and transition towards high-quality development.As a result,how to measure and assess the carrying capacity of water resources in the Qingjiang River Basin is a critical issue that must be addressed in order to achieve high-quality development of the Qingjiang River and even the Yangtze River.Based on the research framework of system characteristic analysis-index system construction-evaluation method determination-carrying potential measurement-alarm state evaluation,the dissertation uses the methods of extreme difference method,entropy power method,TOPSIS,CPM,time difference correlation coefficient analysis,regression analysis,etc.to evaluate water resources carrying capacity of Qingjiang River Basin.The main research work and conclusions are as follows:1.The actual value and the " Three Lines One Permit " control value differed,and a single evaluation is constructed to judge the carrying status and early warning level of the current and predicted values of the evaluation indexes.In terms of water resources,the carrying capacity and alert degree of socio-economic and industrial development show a good development trend,and the state is "safe"(green light)after 2026,but agricultural production overload is severe,and only Yidu City in 2021-2023 is in a bearable state,and the alert degree is moderate.The water environment dimension,bearing status and alert degree of industrial development,agricultural production,and urban construction are all developing well,with the alert degree of water quality standards of water sources in a "safe" state(green light);the water ecology dimension,bearing status of ecological protection,showing the first "safe" state(green light).The bearing status of ecological protection shows a positive trend changing from overloading to being loadable,and the warning degree decreases from "serious level warning"(red light)to "safe" state(green light).2.The integrated evaluation method of TOPSIS and CPM was constructed to measure the carrying capacity of the Qingjiang River Basin.In general,the development of the Qingjiang River Basin’s water resources carrying capacity is good,and the warning degree is in the "relatively safe" or below warning state from 2010 to2020(blue and green light).The carrying capacity of water resources will continue to improve from 2021 to 2030,although the growth will be minor,and the warning level will remain "safe"(green light).There are major spatial variances,particularly in Enshi,which has the highest water resource carrying capacity and the alert degree is "safe"(green light),whereas Yidu has the lowest and the alert degree is "relatively safe" and below.Although some counties and cities are mildly overburdened,the rate of overload decreases with time.The water resource carrying capacity of ten counties and cities is in the bearable range in 2021–2030,and the alert level is "safe"(green light).From 2010 to 2030,the increase of the water ecological dimension bearing index is greater than that of the water quantity and water environment dimension,which also reflects the national positioning of the Qingjiang River Basin as the national key ecological function-oriented zones.3.In ten counties and cities,a coupled and coordinated development evaluation is built to judge the degree of development between subsystems and within the system,as well as to reveal the shortcomings of "co-management of three types of water." In general,the trends of coupling degree and coordination degree of water resources carrying capacity of Qingjiang River Basin from 2010 to 2030 are basically the same,which means that the systems coordinate with each other to achieve synchronous development mode;from the perspective of counties and cities,the coupling degree of economic development and ecological environment shows obvious spatial differences,and Yidu City,major function-oriented zones of agricultural products,is always in the low level of development with water ecology lagging behind,which also reflects the characteristics of resource The evaluation of the carrying capacity must be combined with the characteristics of the main function positioning,while Enshi City shows a strong carrying capacity for water environment and water ecology,but shows a weak carrying capacity for the amount of water resources,and the system cannot be coordinated to achieve synchronous development,which belongs to the lagging amount of water resources,and the rest of the counties and cities show the lagging water environment;by 2030,the system tends to be coordinated and orderly development,and the type of coordinated development in the spatial layout in the water resources lagging type,water environment lagging type and water ecology lagging type shows the distribution of 3:5:2.The innovation of this thesis is mainly reflected in the following three aspects.1.Evaluation of water resources carrying capacity of Qingjiang River from a basin-wide perspective,and the exploration of the water resources carrying potential under the corresponding quota target.In this paper,the water resources carrying capacity evaluation is carried out from the combination of ten counties and cities and the whole basin respectively,combining the scientific evaluation of the water resources carrying capacity of the Qingjiang River basin with the quota indicators such as " Three Lines One Permit " as the basis to study and judge the water resources carrying potential of the Qingjiang River basin.2.Water resources carrying capacity evaluation index system and "management policy" combination.Based on the general requirements of ecological civilization construction and the development strategy of Qingjiang River Basin,according to the regional differences of the main functional areas in the Qingjiang River Basin,the general evaluation index system was adjusted through quantitative methods,and different types of differential evaluation index systems were established and linked to environmental control policies to determine the limit values of the "red line".3.The evaluation of water resources carrying capacity of Qingjiang river basin reflects the correspondence between carrying status and early warning level,which enriches and expands the theory and method of water resources carrying capacity evaluation.Early warning is a kind of prediction and evaluation in a higher-level sense.Through a single and integrated evaluation of the water resources carrying capacity of Qingjiang River Basin and combined with the CPM affiliation function,we can judge whether the current situation and future trend of water resources carrying capacity of Qingjiang River Basin are in an alert state and make a prediction on the possibility of hazard.