# The Response of NDVI to Climate Change in the Lowest and Hottest Basin in China
## 1 Introduction  
Vegetation, as a critical component of terrestrial ecosystems, plays an irreplaceable role in regulating regional climate, maintaining biodiversity, and facilitating ecosystem material cycling and energy flow [1, 2, 3]. Its spatiotemporal dynamics not only serve as vital indicatorsfor assessing the health status of terrestrial ecosystems but also represent important research objects for understanding the response mechanisms of land surface processes under global change [4; 5]. Against the backdrop of global climate change, vegetation growth dynamics, spatial distribution patterns, and carbon balances are significantly regulated by climatic factors such as temperature and precipitation [6]. In this context, revealing the response mechanisms of vegetation to climatic factors has emerged as a critical scientific proposition for assessing regional environmental evolution and developing adaptive management strategies [7]. It holds substantial scientific and practical significance for uncovering the patterns of regional environmental quality change, refining soil and water conservation strategies, and advancing ecological protection initiatives [4]. The Normalized Difference Vegetation Index (NDVI), as an effective indicator of vegetation coverage and photosynthetic activity, not only effectively reflects vegetation productivity levels and spatial distribution patterns but also provides reliable data support for multi-temporal vegetation dynamics monitoring [8; 9] and vegetation variability analysis [10; 11], exhibiting unique advantages in ecological monitoring in arid regions. For example, [PERSON] et al. utilized the Google Earth Engine (GEE) platform and found that NDVI growth rates in Xinjiang, China, were significantly higher than those in five Central Asian countries [12]. This disparity was predominantly attributed to differences in water resource management policies [12]. In arid ecosystem contexts, vegetation growth exhibits typical water-limited characteristics due to the dual stressors of scarce precipitation and intensive evapotranspiration processes, rendering it highly sensitive to global climate change [13; 14]. Therefore, establishing a precise vegetation monitoring system and systematically analyzing the dynamics of vegetation coverage, biomass accumulation characteristics, and phenological changes are key scientific issues for understanding the evolutionary mechanisms of ecosystems in arid regions [15]. Currently, theoretical debates persist in research on vegetation-climate responses in arid regions. Global-scale studies indicate that temperature increases significantly enhance vegetation activity by extending the growing season [16]; however, this mechanism may falter in extremely arid areas due to water limitations [17]. For instance, research by [PERSON] et al. has demonstrated that vegetation growth in arid zones is primarily constrained by water availability [18]. Fluctuations in precipitation can directly impact vegetation productivity by altering soil moisture content [18]. At the regional scale, although scholars have conducted in-depth analyses of vegetation cover changes in China's northwestern arid regions and explored the correlations between these changes and climatic variables [19; 20], significant discrepancies exist among research findings. For instance, [PERSON] et al. and [PERSON] et al. found a significant correlation between NDVI and both precipitation and temperature, suggesting that the synergistic effects of water and heat drive vegetation growth [21; 22]. However, [PERSON] et al. and [PERSON] et al., based on the analysis of multi-year remote sensing data, proposed that NDVI changes are significantly correlated with precipitation but not with temperature [19; 20]. Moreover, [PERSON] et al. demonstrated that NDVI has a higher correlation with temperature than with precipitation, indicating that temperature has a more pronounced impact on vegetation growth [23].