In Mongolia, overuse and degradation of groundwater is a serious issue, mainly in the urban and economic hub, Ulaanbaatar, and the Southern Gobi mining hub. In order to explicitly quantify spatio-temporal variations in water availability, a process-based eco-hydrology model, NICE (National Integrated Catchment-based Eco-hydrology), was applied to two contrasting river basins: the Tuul River, which is characteristic of northern grassland and steppe, and the Galba River, characteristic of the southern Gobi Desert. The authors built a high-resolution data grid representing water use for livestock, urban populations, and mining in the entire basins by combining a global dataset, statistical data, GIS data, observation data, and field surveys to improve the accuracy of the model results. The model simulated the effects of past climatic change and human-induced disturbances such as urbanization and mining on water resources during 1980–2018 in these two river basins. The model results showed a clear difference in the hydrologic cycle between them, suggesting the impact of urbanization and mining on local-regional eco-hydrological degradation. Although drinking by herders’ livestock had some impact on the hydrologic change, the groundwater level in the Tuul River was shown to have been extremely degraded by water use in Ulaanbaatar over the last few decades whereas that in the Galba River has declined markedly as a result of Oyu Tolgoi mining since 2010. Analysis of the relative contribution of environmental factors also helped us to separate the effects of climatic change and human activities on spatio-temporal change in the groundwater level. These results clarified the large impact of water use due to urbanization and mining on groundwater degradation around the water sources, in addition to climatic change. This methodology is powerful for evaluating spatio-temporal variations of water availability in regions with fewer inventory data on urbanization and mining.

在蒙古，地下水的过度使用和退化是一个严重的问题，主要在城市和经济枢纽，乌兰巴托和南部戈壁采矿枢纽中。为了明确量化可用水的时空变化，将基于过程的生态水文学模型NICE（基于国家综合集水区的生态水文学）应用于两个截然不同的流域：图尔河，该图尔河的特征是北部的草原和草原，以及戈壁沙漠南部的加尔巴河。作者通过结合全球数据集，统计数据，GIS数据，观测数据和实地调查，建立了代表整个流域牲畜，城市人口和采矿用水的高分辨率数据网格，以提高模型结果的准确性。该模型模拟了这两个流域在1980–2018年期间过去的气候变化和人为干扰（例如城市化和采矿）对水资源的影响。模型结果表明它们之间的水文循环存在明显差异，表明城市化和采矿对局部区域生态水文退化的影响。尽管牧民的牲畜饮水对水文变化有一定影响，但在过去的几十年中，图兰河的地下水水位因乌兰巴托的用水而大大降低，而加尔巴河的地下水位却因此显着下降自2010年以来一直在Oyu Tolgoi进行开采。对环境因素相对贡献的分析还帮助我们区分了气候变化和人类活动对地下水位时空变化的影响。这些结果表明，除了气候变化以外，由于城市化和采矿造成的用水量对水源周围的地下水退化也有很大影响。这种方法对于评估城市化和采矿业库存数据较少的地区的可用水时空变化很有用。