面向绿洲安全和干旱区可持续发展的农业节水潜力研究

Research on Agricultural Water⁃Saving Potential for Oasis Security and Sustainable Development in Arid Areas

为确保用水总量控制下绿洲安全及干旱区可持续发展目标的实现,以新疆开孔河流域为例,提出基于用水总量控制指标、地下水安全等约束条件的干旱区灌溉节水潜力计算新方法。结果表明:1)开孔河流域现状年(2020年)地下水开采量为12.97亿m^(3),灌溉用水总量为34.85亿m^(3);传统节水模式下,流域中期规划年(2030年)节水潜力为0.74亿m^(3),远期规划年(2050年)节水潜力为5.02亿m^(3)。2)在节水潜力新内涵下,开孔河流域中期规划年没有节水潜力,且需要休耕18667 hm^(2),远期规划年节水潜力为1.77亿m^(3)。3)为防止干旱区次生盐渍化,实现水资源短缺的干旱区可持续发展,在节水后应控制绿洲地下水位在3.5~4.0 m之间。对于水土不均衡的干旱区灌区而言,传统节水思路对绿洲安全的重视程度不够,对节水潜力评价过高。

In order to ensure oasis security under total water use control and achieve the sustainable development goals in arid areas,taking the Kaikong River watershed in Xinjiang as an example,a new method for calculating irrigation water⁃saving potential in arid areas was pro⁃posed based on the constraint conditions of total water use control index and groundwater safety.The results show that a)the current annual(2020)groundwater extraction in the Kaikong River watershed is 1.297 billion m^(3)and the total irrigation water is 3.485 billion m^(3).Under the traditional water⁃saving model,the water⁃saving potential of the watershed is 74 million m^(3)in the medium⁃term planning year(2030)and 502 million m^(3)in the long⁃term planning year(2050).b)Under the new connotation of water⁃saving potential,there is no water⁃saving po⁃tential in the Kaikong River watershed in the medium⁃term planning year,and 18667 hm^(2)needs to be fallow,while the longvterm planning annual water⁃saving potential is 177 million m^(3).c)In order to prevent secondary salinization in arid areas and achieve sustainable develop⁃ment in arid areas with water shortage,the groundwater level of oasis should be controlled between 3.5 m and 4.0 m after saving water.For the irrigation area with water and soil imbalance,the importance of oasis safety is not enough under the traditional water⁃saving thinking,and the evaluation of water⁃saving potential is too high.