Water plays a vital role in sustaining the natural functioning of the entire ecosystem that supports life on Earth. It plays key roles in the well‐being of society in numerous ways. However, climate variability and land use land cover (LULC) change have caused spatiotemporal water supply variation. Disentangling the effects of climate variability from LULC change on water supply is crucial for sustainable water resource management. The main purpose of this study is, therefore, to disentangle the relative contribution of LULC change and climate variability to the overall average annual water supply variation. Residual trends analysis combined with Integrated Valuation of Environmental Services and Tradeoffs (InVEST) annual water yield model was adopted to perform simulations and disentangle the relative impacts of climate variability and LULC change. Ground and satellite data were used in this study. The study area has experienced a significant increasing wetness trend and significant LULC dynamics between 2003 and 2017. As a result, an increasing water supply was observed due to the joint effects of climate variability and LULC change in the watershed (203 mm). The contribution of climate variability was 94%, whereas LULC contributes only 6% from 2003 to 2017. Climate variability negatively led to water supply variation while LULC change contributed positively from 2010 to 2017. Although the ongoing soil and water conservation (SWC) practices improved vegetation cover and water retention of the watershed, climate variability is the main driver of water supply variation. Therefore, SWC practices should incorporate ecosystem‐based climate change adaptation strategies and scale up to community‐based integrated watershed management to sustain water supply.

中文翻译：

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划分青尼罗河流域源区的土地利用/土地覆盖变化和气候变化对供水的影响

水在维持支持地球生命的整个生态系统的自然功能中起着至关重要的作用。它以多种方式在社会福祉中发挥关键作用。但是，气候变化和土地利用土地覆盖（LULC）的变化已引起时空供水变化。区分气候变化与土地利用，土地利用变化的变化对供水的影响对于可持续水资源管理至关重要。因此，这项研究的主要目的是弄清土地利用，土地利用变化的变化和气候变化对总体年均供水变化的相对贡献。采用残留趋势分析结合环境服务与折衷综合评估（InVEST）年度水产量模型来进行模拟，并弄清气候变异性和LULC变化的相对影响。在这项研究中使用了地面和卫星数据。在2003年至2017年期间，研究区域的湿度趋势显着增加，LULC的动态也很显着。结果，由于气候变化和流域LULC变化（203毫米）的共同影响，观测到的供水量增加。从2003年到2017年，气候变化的贡献为94％，而土地利用变化的贡献仅为6％。从2010年至2017年，气候变化对水供应产生负面影响，而土地利用变化的变化为正。尽管正在进行的水土保持（SWC）实践改善了植被覆盖度和流域保水率，但气候多变性是供水变化的主要驱动力。因此，SWC做法应纳入基于生态系统的气候变化适应策略，并扩大到基于社区的综合流域管理，以维持供水。