Decoupling analysis on water resources utilization of planting industry and economic development in Shaanxi Province from the perspective of water footprint

Shaanxi Province is located in a key area of the "One Belt One Road" promoted by China. The availability of agricultural water resources is bound to be further scarce due to accelerated economic transformation as a result of the "One Belt One Road" project. To therefore quantify water footprint of the crop industry and to determine the co-ordination between planting and economic development are critical for further clarification of the water use in planting and setting up relevant reference basis for water resources management in Shaanxi Province. Thus this paper incorporated the loss of water during distribution and irrigation of crop water footprint. By accounting for the value of water footprint of the crop industry in Shaanxi Province for the period 2005-2016, we analyzed the spatial and temporal differences in water consumption by various crops in Shaanxi Province, the utilization efficiency of green water and the pressure of water environment. Combined with the Tapio model, the change in relationship between economic growth of crop farming, water resource utilization and water environment was determined. The results showed that:1) water consumption by various crops was significantly different during the study period. The water footprint of vegetables and fruits were respectively 0.42 m³·kg^-1 and 0.51 m³·kg^-1, while that of tea was as high as 30.29 m³·kg^-1. However, there was an overall downward trend in water use. 2) The water consumption composition of planting industry in different areas was quite different, crop water consumption proportion in Guanzhong was 69.59%, grain and corn water consumption proportion in northern Shaanxi was 75.16% and that in southern Shaanxi was relative equilibrium among various corps. The water consumption composition was basically the same as water endowment and crop water footprint. 3) The use efficiency of green water footprint was relatively low. Also the pressure index of water environment was low in the south, high in the central and north. The average water environment pressure index for Xianyang was as high as 4.75 in 12 years, indicating serious water environment pressure. 4) The decoupling of economic growth of crop industry with water resource use and water environment pressure accounted respectively for 45.45% and 27.27% of total water use in the province. The research results showed that planting structure in Shaanxi Province was relatively reasonable and that green water footprint was hugely utilized. The efficiency and pressure of water environment still needed improvement. The relationship between economic growth of crop industry and water resources use was being gradually transformed from primary co-ordination of weak decoupling to quality co-ordination of strong decoupling. However, it still faced the change of industrial diversity, economic growth and environmental pressures.