Dynamic Prediction And Regulation Of Water Resources Carrying Capacity In Yellow River Basin Based On System Dynamics Theory

Given the increasingly serious ecological and environmental problems in the Yellow River basin,ecological protection and high-quality development of the basin have been listed as one of the five major national development strategies.In this context,carrying out research on dynamic prediction and regulation of water resources carrying capacity in the Yellow River basin is of great significance for improving the carrying capacity of economy and population,promoting ecological protection and high-quality development in the whole basin.The Yellow River basin is a typical basin with severe water shortage,which is characterized by prominent contradiction between supply and demand.Based on the feedback mechanism of "population-economic society-water" system,the water quantity and water quality factors of water resources carrying capacity in the Yellow River basin was evaluated from 2004 to 2017,and multi-scenario dynamic prediction of carrying capacity in different development periods was carried out.According to the regulation goal,a quantitative regulation scheme was proposed to improve the carrying capacity and reduce the load in the basin,and the critical/loadable state would be reached by optimizing the regulation variables.The water quantity and water quality factors of water resources carrying capacity in the Yellow River basin was evaluated from 2004 to 2017 by the single-factor evaluation method.The evaluation results of different evaluation years and study zones showed that the water quantity factors were poor as a whole,and most of the years and regions were in the overload state.According to the water quality evaluation results in 2017,the water quality in the upper,middle and lower reaches of the Yellow River basin was not overloaded,overloaded and not overloaded respectively.Based on system dynamics,a prediction model of water resources carrying capacity in the Yellow River basin was constructed,and the water quantity factors of carrying capacity in planning level year was dynamically predicted.The available water and water consumption in 2030,2035 and 2050 were predicted based on two different scenarios.The results showed that before the Western Route Project of South-to-North Water Diversion and other water diversion projects come into effect,the whole basin is overloaded at three planning levels.After the Western Route Project of South-to-North Water Diversion and other water diversion projects come into effect,the middle reaches will be loadable in 2030 and 2035,while the rest of the region will remain overloaded but with a reduced degree of overloading.Based on the results of the orthogonal experiment,a quantitative regulation scheme for carrying capacity improvement and carrying load reduction in the Yellow River basin was proposed.According to the Yellow River basin water resources carrying capacity regulation target,the grey relative analysis method was used to screen for regulation index which has a great influence on the carrying capacity.From the perspectives of improving the carrying capacity and reducing the carrying load,the orthogonal experiment method was used to set up 9 sets of control schemes before and after the Western Route Project of South-to-North Water came into effect,and the optimal control schemes in the upper,middle and lower reaches in 2030,2035 and 2050 were selected.The corresponding regulation suggestions were proposed to ensure that the carrying capacity of the Yellow River basin is no longer overloaded in each level of annual average.