Evaluating the importance of water conservation function in Bashang area , Zhangjiakou

Based on the InVEST model, the water conservation function of Zhangbei Dam was quantitatively evaluated, the importance level of water conservation was identified, and the spatial distribution characteristics were analyzed, providing a scientific basis for enhancing the water conservation function of Zhangbei County. The total water conservation in this county was 1.42 × 10⁸ m³, the average depth was 33.98 mm, and the spatial distribution was uneven. Water conservation was directly proportional to rainfall and inversely proportional to potential evapotranspiration. Forest land had the strongest water conservation capacity, and dry land had the highest total water conservation. Water conservation was of medium importance, and human activities were concentrated in this region . Dry land and low water conservation were widely distributed. The most important water conservation areas were distributed in sparse woodland and grassland in the eastern, southern, and central regions. The main reason for the low water conservation and importance in Zhangbei County was the sparsity of forest land and grassland and the wide distribution of dry land. Projects that return farmland to grassland and forests should be continued to improve the county’s water conservation capacity by retaining the appropriate dry-land scale.