祁连山国家公园产水量时空变化及驱动因素分析

为准确表征祁连山国家公园产水量时空差异性,探究产水量影响因素和驱动机制。基于降水量、参考作物蒸散量、土壤深度、根系深度和土地利用类型等参数,利用InVEST模型可视化祁连山国家公园1990—2018年产水量时空格局,使用地理探测器并结合情景模拟方法,评估和量化气候、土地利用、植被、地形等因子对祁连山国家公园产水量空间异质性和产水量变化的影响。结果表明：(1)1990—2018年研究区产水量以0.56×10⁸ m³/a的速度显著增加,在空间上呈自西向东递增趋势;(2)耕地和林地产水深度最大,未利用土地和草地是研究区产水量的主要贡献者,且产水深度高值区位于3 200～4 600 m高海拔处;(3)降水量是产水量空间异质性的第一驱动因素,与实际蒸散量以及土地利用类型的交互作用占主导地位;(4)1990—2018年,气候变化是产水量变化的主要驱动因子,对总产水量影响为正向作用,其次为土地利用变化,主要影响产水量变化的空间分布,对总产水量影响不大。研究成果可进一步为祁连山国家公园水资源管理和可持续发展提供基础理论依据。

Analysis of the Spatial-temporal Variation and Driving Factors of Water Yield in Qilian Mountain National Park

To accurately characterize the spatial and temporal heterogeneity of water yield in Qilian Mountains National Park and explore the influencing factors and driving mechanisms affecting water yield. The InVEST model was used to visualise the spatial and temporal pattern of water yield in the Qilian Mountains National Park from 1990 to 2018 based on the parameters of precipitation, evapotranspiration of reference crops, soil depth, root depth, and land use type, using a geo-detector and combined with a scenario simulation methods to assess and quantify the effects of climate, land use, vegetation, terrain, and other factors on the spatial heterogeneity and changes in water yield in the Qilian Mountains National Park. The results showed that: (1) From 1990 to 2018, the water yield in the study area increased significantly with a trend of 0.56×10⁸ m³/a, with a spatial increasing trend from west to east. (2) Farmland and Forestland had the largest water yield depth, and Unused land and Grassland were the main contributors to water yield in the study area. The high-value water yield depth areas were located at high altitudes between 3 200 m to 4 600 m. (3) Precipitation was the first driver of spatial heterogeneity of water yield, and the interaction with actual evapotranspiration and land use type dominates. (4) From 1990 to 2018, climate change was the main driver of changes in water yield, with a positive effect on total water yield, followed by land use change, which mainly affects the spatial distribution of water yield change but had little effect on total water yield. The research results can further provide the basic theoretical for the water resources management and sustainable development of Qilian Mountain National Park.