三峡库区水供给服务供需关系动态变化及演化趋势分析

Dynamic Change and Evolutionary Trend in the Supply and Demand Relationship of Water Supply Services in the Three Gorges Reservoir Area

水供给服务作为一项非常重要的生态系统服务,在水循环平衡调节和人类生产、生活、生态中发挥着重要作用。基于InVEST模型对三峡库区水源供给量评估,采用人口、工业、生态农业用水指标求取水需求量;然后计算水供给服务的供需比,揭示其供需关系的空间差异;最后分析三峡库区水供给服务供需不匹配影响因素,明确其空间自相关性及演化趋势。结果表明:2000—2015年,三峡库区水供给服务总量呈现先减少后缓慢增加的趋势,共缩减了1.13×10^(10)m^(3),下降了19.68%,中部地区产水深度大于东部地区;2000—2015年,三峡库区水供给服务的需求总量逐年增加,共增加了11.37×10^(8)m^(3),增长率402.93%,需水量从西向东逐级递减;2000—2015年,三峡库区供需比例从20.69%降低到10.66%,供需关系逐年紧张;三峡库区水供给服务的供需关系始终存在着显著的空间正相关,供需关系的集聚效应有所加强,受土地利用、经济结构、水资源条件、气候降水等因素影响。维持区域水资源平衡,需合理配置生产、生活、生态水,减少供需不匹配的影响。

As a very important ecosystem service,water supply service plays an important role in the regulation of water cycle balance and human production,life and ecology.Based on the InVEST model,the water supply in the Three Gorges Reservoir area was evaluated,and the water demand was calculated by using the water consumption indicators of population,industry and ecological agriculture.Then,the supply-demand ratio of water supply services was calculated to reveal the spatial differences in their supply-demand relationship.Finally,the factors influencing the mismatch between supply and demand of water supply services of Three Gorges Reservoir area were analyzed and its spatial autocorrelation and evolutionary trends were clarified.The results show that the total amount of water supply services in the Three Gorges Reservoir area shows decreasing firstly and then increasing slowly,with a total reduction of 1.13×10^(10)m^(3),decreasing by 19.68%.The depth of water production in the central region is greater than that in the eastern region.From 2000 to 2015,the total demand for water supply services in the Three Gorges Reservoir area has increased year by year,with a total increase of 11.37×10^(8)m^(3),with a growth rate of 402.93%.The water demand decreases step by step from west to east.From 2000 to 2015,the ratio of supply to demand in the Three Gorges Reservoir area has decreased from 20.69%to 10.66%,and the supply-demand relationship has tightened year by year.There is always a significantly positive spatial correlation between the supply and demand of water supply services in the Three Gorges Reservoir area,and the agglomeration effect of supply and demand has been strengthened,which is influenced by factors such as land use,economic structure,water resources conditions and climatic precipitation.To maintain the balance of regional water resources,it is necessary to rationally allocate production,living and ecological water to reduce the impact of the mismatch between supply and demand.