Analysis of sustainable use efficiency of provincial water resources

Due to severe water shortage, water quality deterioration and aquatic ecosystem degradation, it is highly urgent to adopt efficient and sustainable use of water resources in China. To improve the sustainable use efficiency of provincial water resources in China, this paper estimated and analyzed water sustainable use efficiencies in 26 provinces using the DEA(BCC) model. While the model input variables included land area, and amount of water resources below Grade Ⅲ, the output variables included GDP and population. The Tobit regression analysis was used to screen key factors that influenced sustainable use of provincial water resources from the listed total possible influencing factors. Such factors included proportions of added value of primary industry, secondary industry and tertiary industry to GDP; proportion of arable land to land area, forest cover, irrigated area rate and investment in environmental protection per area. The results showed that large-scale of province area and unreasonable water use resulted in overall low efficiency of sustainable use of water in the investigated provinces. Total efficiency, technology efficiency and scale efficiency were 0.303, 0.592 and 0.513, respectively. Inter-provincial differences in overall efficiency was great with variation coefficient of 1.010 implying that there existed the potential to improve the sustainable use efficiency of water resources in the country. There were three most important factors that influenced provincial water sustainable use efficiency. The factors included proportion of added value of primary industry to GDP, investment in environmental protection per area and arable land rate, with effect coefficients of ?0.015 7, 0.014 2 and 0.004 8, respectively. Since the proportion of added value of primary industry to GDP had the highest negative effect on the sustainable use efficiency of provincial water resources, it was essential to promote industrialization and urbanization to reduce this effect. This in turn increased not only economic output per unit water resources, but also improved water use efficiency across the country. The environmental investment per area had significant positive effect on the sustainable use efficiency of water resources. This indicated that increased environmental protection investment favored use efficiency of water in the country. Arable lands had better water conditions than non-arable lands and were also more conducive to natural water cycle than urban and industrial lands. The arable land rate positively influenced water resources sustainable use efficiency. Comprehensive analysis showed that promoting industrialization, urbanization and agricultural modernization along with the protection and sustainable use of arable lands, adjustment of economic development structures, and increase in environmental protection could improve the sustainable use of provincial water resources in China.