This study focuses on the lower reaches of the Heihe river in Northwest China’s arid region, utilizing MOD13 Q1-NDVI data from 2000 to 2022, complemented by concurrent temperature (Tem) and precipitation (Pre) records, to investigate the spatiotemporal dynamics of fractional vegetation cover (FVC) and its response mechanisms in the context of climate change. The findings reveal that: 1) The FVC in the lower Heihe river region exhibits an overall trend of slow, fluctuating improvement, indicating a gradual recovery. However, the FVC remains relatively low, with the core oasis areas displaying weak ecological stability. These regions are highly susceptible to the impacts of climate change and human activities, thus exhibiting significant ecological fragility. 2) Climate change in the lower Heihe river region is influenced by global trends while it exhibits distinct local characteristics. The region has experienced a pronounced warming trend with notable fluctuations in Tem increases. Meanwhile, Pre has shown a slight decline, characterized by highly unstable interannual variability. The increasing aridity of the climate has further exacerbated the risk of vegetation degradation. 3) The relationship between FVC changes and Tem or Pre is weakly correlated. These climatic factors have influence on FVC, but they are not the primary drivers. FVC is also significantly affected and constrained by other factors such as surface water availability, groundwater levels, and soil salinity. 

以中国西北干旱区的黑河下游地区为研究对象, 基于2000—2022年的MOD13 Q1-NDVI数据, 结合同期温度和降水数据, 深入探讨气候变化背景下该地区植被覆盖度(FVC)的时空变化特征及对气候变化的响应机制, 获得以下结果。1) 黑河下游地区植被覆盖度总体上呈现缓慢的波动上升趋势, 显示出逐渐趋于改善和恢复发展的态势。然而, 该地区植被覆盖度整体水平仍然较低, 核心绿洲区的植被生态稳定性相对较弱, 极易受气候变化和人类活动影响, 表现出较高的生态脆弱性。2) 黑河下游的气候变化既受全球气候变化大背景影响, 又具有区域气候变化的局地特殊性。气温呈明显变暖趋势, 且升温幅度存在明显的波动性; 降水量呈略微减小的趋势, 年际变化极不稳定, 气候干旱趋势显著, 导致植被衰退风险进一步加剧。3) 植被覆盖度总体上与气温和降水量弱相关, 表明气温和降雨量对区内植被覆盖度有一定的影响, 但并非主控因子。植被覆盖度还受到地表水、地下水和土壤水含盐量等多种因子的共同影响和制约。