为了探究长江经济带用水结构演变特点,根据长江经济带11个省(市)2003—2020年用水量变化,采用信息熵和均衡度的理论方法,分析其用水结构特征及演变趋势,并结合主成分分析法进行了驱动力分析。结果表明:在时间尺度上,长江经济带用水总量总体呈上升趋势,其中农业、工业用水比例下降,生活、生态用水比例增加;用水结构信息熵、均衡度均呈上升趋势,用水系统均衡性增强。在空间尺度上,长江经济带下游用水系统均衡性最高,其次是上游、中游。随着农业结构的调整,预计长江流域耕地面积可能会减少,农业用水量不会有大幅上升,其占比将继续减少。预计工业用水量可能会减少,占比依然下降;生活用水量会继续提高。用水结构演变的主要驱动力有工业生产总值、GDP、节水灌溉面积、万元GDP用水量4个因子,其贡献率占96.844%。研究结果对长江水资源与生态保护具有重要参考价值。

The characteristics and evolution trend of water use structure in the Yangtze River Economic Belt are analyzed according to the changes in water consumption of eleven provinces (cities) from 2003 to 2020 by using theoretical methods of information entropy and equilibrium degree. The driving forces are also examined via principal component analysis. Results manifest that on the time scale, the total water consumption of the Yangtze River Economic Zone is on the rise. The proportion of agricultural and industrial water consumption has declined, while the proportion of domestic and ecological water consumption has increased; the information entropy and equilibrium degree of water use structure have both increased, and the water use system is more balanced. On the spatial scale, the water consumption system in the lower reach of the Yangtze River Economic Belt is the most balanced, followed by that in the upper reach and the middle reach in sequence. With the adjustment of agricultural structure, it is expected that the area of arable land in the Yangtze River Basin may shrink, and the amount of agricultural water consumption will not rise sharply, with its proportion continue to drop. It is expected that industrial water consumption may fall, and its proportion will still decrease; domestic water consumption will continue to increase. The major driving forces for the evolution of water use structure are total industrial production value, GDP, water-saving irrigation area, and water consumption per 10 000 yuan of GDP, together contributing 96.8% to the changes.