Spatio-temporal evolution analysis and underlying driving forces of water supply and consumption structures in Zhangjiakou, China

Studies involving the spatio-temporal evolution and underlying driving forces of water supply structures are of extremely important for implementation of rational allocation of water resources and improvement of water supply efficiency. Based on meteorological data, water supply and consumption data, social-economic data and water environmental data from Zhangjiakou City, China, the spatial and temporal evolution and driving forces affecting water supply structures were studied using multiple methods of mathematical and spatial statistical mapping, comentropy, equilibrium degree, and the grey correlation model. The results showed that, Zhangjiakou shortage of surface water, and the proportion of ground water supply continues to increase, Additionally, the results report increase in the total amount of water supply and widening of the spatial difference in water supply. Agricultural water consumption constitutes the greastest ues of water, but the total amount and proportion of agricultural water consumption continue to decrease, while the proportions of industrial and domestic water consumption continue to increasing. Ecological and environmental water supply has also increased significantly in recent years, but the totaland proportion of water consumption represented bu these sectors are not considerable. The total amount of water consumption showed a downward trend. Form 2006 to 2011, the equilibrium degree dropped sharply, and the water consumption structure was extremely unbalanced. The water consumption equilibrium degree increased rapidly in 2011–2017, and the water consumption structure developed toward equilibrium, but entropy and equilibrium degree were both low, and there is plenty of room for structural adjustments. As for the driving forces, the correlation between effectively irrigated area and added secondary industry value is "strong", whereas the correlations between irrigated area and other factors are "medium". The increase in human population, the expansion of the city, and the changing of ecological environment have resulted in increased domestic and ecological water consumption, which have become the important driving factors affecting the evolution of water consumption structure.