Evaluation of grassland carrying capacity and its constraint of water resources in Mongolia

In Mongolia, the traditional pastoral system has changed by the overuse and degradation of water resources. Currently, there is a research gap between the socio-economic transition and ecosystem degradation on the existing knowledge. In the present study, a process-based eco-hydrology model, NICE (National Integrated Catchment-based Eco-hydrology) (Nakayama et al., 2021a, 2021b, 2023), was applied to the total of 29 river basins in the entire country to quantify the heterogeneous distribution of livestock water use and its relation to pasture degradation there (Nakayama, 2025). The authors also evaluated the change of grassland carrying capacity and carrying status index during the last few decades (Yan et al., 2023). The result showed that the livestock water use in entire basins was the same order of magnitude as mining and urban water uses and that the estimated total water use was similar to that on constant assumption in the previous study. In addition, the simulation also clarified heterogeneous distributions of water uses of 5 types of typical livestock and higher water use in the central part of the country. However, the carrying status index showed more serious situation of overgrazing in the transitional zone between grassland and the Gobi desert. This means that the excessive use of water resources is indirectly related to the degradation of natural vegetation in grassland. These results also imply that the excessive use of livestock water intake can lead to groundwater decline, grassland degradation, and ultimately a reduction in the amount of water available to each livestock head. This methodology is effective to evaluate the grassland carrying capacity and its constraint of water resources (Lu et al., 2020), and to propose solutions to unsustainable pastoral land use patterns.

 

References

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Nakayama, T., et al. 2023. Ecohydrology & Hydrobiology, 23(4), 542-553, doi:10.1016/j.ecohyd.2023.04.006.

Nakayama, T. 2025. Environmental Science and Pollution Research, 32, 13626-13637, doi:10.1007/s11356-025-36083-2.

Yan, N., et al. 2023. Ecological Indicators, 146, 109868, doi:10.1016/j.ecolind.2023.109868.