京津冀水资源利用多效率指标的变化特征比较

提高水资源利用效率,缓解用水压力,是解决京津冀缺水问题的有效措施,对各行业用水效率历史状况的全局把握有助于未来政策的调整。论文比较了京津冀三地的万元GDP用水量、万元工业增加值用水量、管网漏损率、人均日生活用水量、污水处理率、作物水分利用效率共6项指标组成的综合用水效率,分析了2002—2017年京津冀用水效率的Mann-Kendall突变点和趋势变化,并基于Burg算法功率谱估计分析了各指标的周期变化特征,计算了各指标基于Burg算法的功率谱。结果表明,在产业结构优化调整和节水技术提升等措施的共同作用下,三地用水效率指标的差异在逐渐缩小,显示了京津冀协同发展的效应,但仍有明显的发展差异。北京、河北的综合用水效率整体呈增长趋势,河北的增长率(0.16)明显高于北京(0.07),而天津的综合用水效率整体上呈下降趋势(-0.03),重点表现在万元GDP用水量和万元工业增加值用水量的增加(0.18、0.19)。北京综合用水效率整体呈现5 a(周期强度为77 dB)、3 a(73 dB)左右的周期,天津综合用水效率整体呈现7 a(88 dB)、2 a(81 dB)左右的周期,河北综合用水效率整体呈现3 a(81 dB)左右的周期。相比于北京和河北,天津综合用水效率的周期性更强,这意味着可以适时地利用其内在周期调控用水效率的变化趋势。

Comparison of the variation characteristics of water resource use efficiency indicators in the Beijing-Tianjin-Hebei region

Improving the efficiency of water resource use and relieving water pressure are effective measures to solve the water shortage problem in the Beijing-Tianjin-Hebei region. An overall understanding of the historical situation of water use efficiency in various industries is conducive to future policy adjustments. In this study, we compared the comprehensive water use efficiency composed of six indicators, including water consumption per 10000 yuan of GDP, water consumption per 10000 yuan of industrial added value, water pipe network leakage rate, daily domestic water consumption per capita, sewage treatment rate, and water use efficiency of crops (WUE). Then the Mann-Kendall abrupt transition point and trend change of water use efficiency in the region from 2002 to 2017 were analyzed, and the periodic variation characteristics of each indicator were analyzed based on power spectrum estimation with the Burg method. The results show that, under the combined action of industrial structure optimization and adjustment and water-saving technology improvement, the differences of water use efficiency between the three areas of the region were gradually narrowing, showing the effect of coordinated development in the Beijing-Tianjin-Hebei region, but there were still significant development differences. The overall water use efficiency in Beijing and Hebei showed an increasing trend, and the growth rate of Hebei (0.16) was significantly higher than that of Beijing (0.07). The overall water use efficiency of Tianjin showed a decreasing trend (-0.03), which was mainly reflected in the increase of water consumption per 10000 yuan of GDP and water consumption per 10000 yuan of industrial added value (0.18, 0.19). In addition, water use efficiency in Beijing as a whole presented a cycle of about 5-year (77 dB) and 3-year (73 dB), while water use efficiency in Tianjin as a whole presented a cycle of about 7-year (88 dB) and 2-year (81 dB). Compared with Beijing and Hebei, Tianjin's comprehensive water use efficiency was more cyclical, which means that its internal cycle can be used to regulate the changing trend of water use efficiency in a timely manner.