蓝绿水供需关系与可调配量评估方法研究

Research on the supply-demand relationship of blue and green water and the evaluation method of deployable resources

针对即使是水资源相对丰富地区其内部也存在水资源供需矛盾的问题,该文提出一种蓝绿水供需关系与可调配量评估研究方法来有效评价流域内部供需关系以及为对应的资源调配方案提供一定理论支持。该方法首先通过SWAT模型在子流域尺度上模拟了蓝绿水资源量,结合人类用水数据,采用蓝绿水稀缺指数评价其供需关系,然后依据不同的生态流量标准将流域内部不同地区蓝、绿水供需关系划分为良好、平衡、略微失衡、失衡4个等级,最后根据供需关系等级量化流域内不同地区的可调配水资源量。以乌江流域为例,计算结果表明,2010—2019年流域整体蓝水稀缺指数范围为0.47~0.81,蓝水供需关系良好,并且可向外年均输送约5.6×10^(9)m^(3)蓝水资源;绿水稀缺指数范围为0.89~1.01,绿水供需关系较为平衡。流域内部有2个蓝水供需略微失衡子流域,1个蓝水供需失衡子流域,而接近半数子流域处于绿水供需略微失衡状态,在空间上呈东北紧张,西南良好的布局,暴露出一定隐患。在极端干旱条件下,流域内共9个子流域用水风险等级提升,其中西南部地区新增2个供需失衡子流域,蓝水供需失衡的风险增加。

Even in areas with relatively abundant water resources, there is still a contradiction between water supply and demand within them. Therefore, a research method was proposed in this paper for evaluating the supply-demand relationship and allocatable amount of blue-green water to effectively evaluate the supply-demand relationship within the watershed and provide theoretical support for corresponding resource allocation plans. Firstly, the amount of blue-green water resources at the sub watershed scale was simulated using the soil and water assessment tool(SWAT) model. Combined with human water use data, the blue-green water scarcity index was used to evaluate its supply-demand relationship. Then, based on different ecological flow standards, the supply-demand relationship of blue-green water in different areas within the watershed was divided into four levels, including good, balanced, slightly imbalanced and imbalanced. Finally, the amount of distributable water resources in areas with relatively abundant water resources was quantified. Taking the Wujiang River Basin as an example, the calculation results showed that the overall blue water scarcity index range of the basin from 2010 to 2019 was 0.47 to 0.81.The supply and demand relationship of blue water was good, and it could transport about 5.6×10^(9) m^(3) annually to the outside blue water resources;The scarcity index of green water ranged from 0.89 to 1.01,indicating a relatively balanced supply-demand relationship. There were two sub basins with slightly imbalanced supply and demand of blue water within the basin, and one sub basin with imbalanced supply and demand of blue water. Nearly half of the sub basins were in a slightly imbalanced state of green water supply and demand, showing a spatial tension in the northeast and a good layout in the southwest, exposing certain hidden dangers. Under extreme drought conditions, a total of 9 sub basins in the basin had increased their water use risk levels, with 2 new sub basins in the southwest region experiencing supply-demand imbalance and an increased risk of blue water supply-demand imbalance.