Study On Water Footprint Of Coastal Cities In Shandong Peninsula

The total amount of water resources on the earth is abundant while the fresh water resources that can be directly used by humans are extremely scarce.Social development is accompanied by the increased water consumption and the scarce water resources.Moreover,water pollution has deteriorated global water crisis.As one of the core areas of economic development in China,Shandong Peninsula has shown rapid economic development.However,the unreasonable utilization of water resources has led to the serious overexploitation of groundwater,the aggravation of soil and water loss,severe water pollution,and the deterioration of water environment.Therefore,the rational allocation and management of water resources have attracted wide attention.The water footprint theory provides a new method for comprehensive and scientifical evaluation of water resources.Water footprint method can qualitatively and quantitatively evaluate regional water resources by combining water quantity and water quality.This study quantified the water footprints of seven coastal cities(Qingdao,Yantai,Weihai,Rizhao,Weifang,Binzhou and Dongying)in Shandong Peninsula from 2011 to 2020 based on water footprint theory.Regression analysis and Logarithmic Mean Divisia Index(LMDI)model were used to explore the influencing factors of water footprint.This study also evaluated the water footprint sustainability,water footprint intensity and per capita water footprint.The main results included:(1)The total water footprint of coastal cities in Shandong Peninsula decreased significantly from 36.692 billion m~3in 2011 to 26.695 billion m~3in 2020 with a decrease rate of 27.25%.Total green water footprint and blue water footprint fluctuated significantly with the total green water footprint of 8.326 billion m~3and the total blue water footprint of 13.376 billion m~3in 2020.The total grey water footprint decreased significantly from 13.115 billion m~3in 2011 to 4.993 billion m~3in 2020 with a decrease rate of 61.93%.Among the seven cities,Weifang had the highest annual contribution rate of 26.91%to the total water footprint of coastal cities in Shandong Peninsula while Weihai had the lowest annual contribution rate of 5.59%.The structure of the water footprint of each city was similar with that the proportion of blue water footprint was the highest,followed by the proportion of green water footprint,and the proportion of gray water footprint had decreased significantly since 2012.(2)The results of regression analysis showed that precipitation and water resources positively affected the green water footprint but negatively affected the blue water footprint.The cultivated land area and pollutant discharge were the positive driving factors for the changes of total water footprint and gray water footprint.The LMDI model decomposition showed that population and economy were the positive driving factors affecting the change of water footprint,among which the economic impact was more significant.Technology was the negative driver of water footprint change,and the impact on water footprint was the most remarkable.The impact of demographic factors,economic factors,and technical factors on the water footprint of each city was different in stability.For coastal cities in Shandong Peninsula as a whole,population had the least significant but greatly stable effect on the water footprint.Technology level had the most remarkable and unstable effect on water footprint.(3)The green water footprint of coastal cities in Shandong Peninsula was sustainable every year with the sufficient green water resources.Among the seven cities,only Weihai and Rizhao had a sustainable blue water footprint in some years.Shortage of blue water resources occurred in coastal cities of Shandong Peninsula while the blue water footprint was not sustainable.The gray water footprint of coastal cities in Shandong Peninsula was sustainable in most of years and the water environment was in positive condition.The water environment of Dongying and Binzhou was improved significantly.Water shortage situation of different cities varied.The coastal city of Shandong Peninsula was in moderate shortage of water resources which was not sustainable.Water shortage situation of Dongying and Binzhou was more severe.(4)The water footprint intensity of coastal cities in Shandong Peninsula decreased significantly from 169.37 m~3/10,000 CNY in 2011 to 72.93 m~3/10,000 CNY in 2020with a decrease rate of 56.94%.Water resource utilization efficiency was improved,and the economic benefits of water footprint increased significantly.The per capita water footprint of coastal cities in Shandong Peninsula decreased from 169.37m~3/person in 2011 to 72.93 m~3/person in 2020 with a decrease rate of 31.46%,indicating a significant improvement in water resource utilization efficiency.The water footprint intensity and per capita water footprint of Binzhou were higher than those of other cities.Water resource utilization efficiency of Binzhou was lower than that of other cities.Qingdao had the lowest water footprint intensity and per capita water footprint while the water resource utilization efficiency and water footprint economic benefit were higher.