Coupled Coordination Of Water-Energy-Food-Economy System And Its Influence Factors In The Yellow River Basin

Water,energy and food are the basic resources supporting the development of human society.Water is the basic material for industrial and agricultural development,energy drives the development of human society,and food is the prerequisite and condition for human survival.The three are interrelated and inseparable.Economy represents the consumption and output of human activities,and has mutual influence with water,energy and food.As the largest basin in the north China,the Yellow River Basin is an important grain production base in our country,which helps ensuring the food security of the region and the whole country.In addition,the Yellow River Basin is an important energy producing area in China,with abundant mineral resources,however,the water resource in this area only accounts for about 3% of the country,and the economy in this area is not balanced,so it is very necessary to analyze the relationship between water-energy-food-economy system systematically.Based on the current situation of the Yellow River Basin,this study took the Yellow River Basin as the research area,constructed comprehensive evaluation index system of water-energy-food-economy system,used the comprehensive evaluation model to evaluate the comprehensive development level of water-energy-food-economy system,and calculated the coupling degree and coupling coordination degree of water-energy-food-economy system through the coupling degree model and coupling coordination degree model.The random forest algorithm was used to study the influencing factors of the coupling coordination degree of water-energy-food-economy system,and the main conclusions were as follows:(1)The comprehensive development index of water-energy-food-economy system in the Yellow River Basin increased significantly from 0.26 to 0.82.The four subsystems of water,energy,food and economy also increased significantly from 0.28,0.43,0.24 and0.01 to 0.84,0.64,0.82 and 0.99,respectively.The comprehensive development index of water-energy-food-economy system in all provinces also showed a significant growth trend,ranging from 0.60 to 0.80 in 2019.The comprehensive development index of water resource subsystem in all provinces fluctuated and increased,while some provinces in energy subsystem and food subsystem showed a decline.From the perspective of space,water subsystem index of the middle and lower reaches were higher than water subsystem index of the upper reaches.Energy subsystem index of the middle reaches were higher than energy subsystem index of the upper reaches and lower reaches.Food subsystem index of the lower reaches were higher than food subsystem index of the middle and upper reaches,and economy subsystem index of the middle and lower reaches were higher than economy subsystem index of the upper reaches.The comprehensive development index of water-energy-food-economy system had different spatial distribution in different periods.(2)The coupling degree of water-energy-food-economy system in the Yellow River Basin was lower than 0.80 in 2000 and 2001,and above 0.80 after 2002,which belonged to the high-level coupling stage.The coupling degree of water-energy-food-economy system in each province was lower than 0.80 years form 2000 to 2002.After 2004,the coupling degree of each province was in the high-level coupling stage.The coupling coordination degree of water-energy-food-economy system in the Yellow River Basin showed a state of marked growth,rising from 0.31 to 0.90,and the coupling coordination degree of each province also showed a significant growth trend.In 2019,the coupling coordination degree of Shaanxi province reached 0.79,while that of other provinces was above 0.80.(3)The effects of different factors on water-energy-food-economy system were quantified by random forest algorithm.In the water subsystem,water consumption for GDP,agricultural water consumption per 10,000 yuan and water consumption structure had significant effects on coupling coordination degree.In the energy subsystem,total energy production,total energy consumption and energy consumption for GDP had significant effects on coupling coordination degree.In the food subsystem,grain yield per unit area,grain yield per capita and effective irrigated area had significant effects on coupling coordination degree.In the economy subsystem,per capita disposable income of urban and rural residents,rural engel coefficient,urbanization rate,GDP and R&D investment intensity had significant effects on coupling coordination degree.In the process of development,attention should be paid to improving water use efficiency and energy utilization efficiency,improving water use structure and energy structure,increasing grain yield and agricultural mechanization level,and increasing residents’ income.