玛纳斯河流域植被生态需水量动态评估

Dynamic assessment of vegetation ecological water demand in Manas River Basin

摘要

【目的】针对西北干旱区内陆河流域生态用水短缺问题,以玛纳斯河流域为研究区,评估植被生态需水量的时空动态变化,揭示自然与人文驱动因子的交互机制,为区域水资源优化配置提供科学依据。【方法】基于玛纳斯河流域的土地利用数据,提取植被面积,利用改进的Penman-Monteith模型,耦合植被系数、土壤水分限制系数,构建植被生态需水量的计算框架,并结合地理探测器,分析气候和人为因素对植被生态需水量的影响。【结果】2000—2020年植被面积以1 047.9 km²/10 a的速率下降,植被生态需水量以8.88×10⁴万m³/10 a的速率下降。土地利用是研究区植被生态需水量变化的核心驱动因子,q值持续稳定在0.93~0.96的高水平范围,其与气候因子存在非线性增强效应。【结论】研究表明,玛纳斯河流域植被生态需水量的变化主要受土地利用与气候因子的耦合驱动,草地面积变化主导总需水量趋势,该结论可为干旱区类似流域的植被生态需水管理提供参考。

Abstract

[Objective] To address the issue of ecological water shortage in inland river basins within the arid regions of northwestern China, the Manas River Basin is selected as the study area to assess the spatiotemporal dynamic changes of vegetation ecological water demand and to reveal the interaction mechanism of natural and human-driven factors, thereby providing a scientific basis for the optimal allocation of regional water resources. [Methods] Based on the land use data of the Manas River Basin, the vegetation area was extracted. An improved Penman-Monteith model, coupled with vegetation coefficients and soil moisture limitation coefficients, was employed to construct a calculation framework for vegetation ecological water demand. Combined with the geodetector, the influence of climatic and human factors on vegetation ecological water demand was analyzed. [Results] From 2000 to 2020, the vegetation coverage area decreased at a rate of 1 047. 9 km² per decade, and the vegetation ecological water demand declined at a rate of 8. 88×10⁸ m³ per decade. Land use was identified as the core driving factor of the changes in the ecological water demand of vegetation in the study area. The q value remained consistently stable within a high level ranging from 0. 93 to 0. 96. A nonlinear enhancement effect was observed between land use and climatic factors. [Conclusion] The study shows that the changes in vegetation ecological water demand in the Manas River Basin are mainly driven by the coupling of land use and climatic factors, and the changes in grassland area dominate the trend of total water demand. The conclusion can provide a reference for the management of vegetation ecological water demand in similar river basins in arid regions.

关键词

植被生态需水量 / 改进的Penman-Monteith模型 / 地理探测器 / 玛纳斯河流域 / 土地利用 / 植被面积 / 时空分布 / 影响因素

Key words

vegetation ecological water demand / improved Penman-Monteith model / geodetector / Manas River Basin / land utilization / vegetation area / spatial and temporal distribution / influencing factors

基金资助

中华人民共和国科学技术部-第三次新疆综合科学考察(2021xjkk0804)

新疆生产建设兵团重点科技攻关计划项目(2021DB012)

新疆生产建设兵团重点科技攻关计划项目(2023AB059)