Impacts of urbanization and climate change on vegetation moisture and water availability in coastal areas

Abstract

Climate change, particularly the accelerating trend of global warming, manifests in diverse ways across different geographical regions of the world. While some regions increasingly experience excessive rainfall and flood events, others face prolonged periods of heat and severe drought. Although our study area – the Absheron Peninsula – is located along the western coast of the Caspian Sea, where coastal proximity typically contributes to higher humidity levels, recent observations reveal a distinctly different trend. Despite its coastal position, the region has been experiencing a noticeable intensification of drought conditions over the past two decades. In order to evaluate the ecological consequences of these climatic shifts, our research focused on assessing the impact of climate change on vegetation cover. For this purpose, we employed the Normalized Difference Moisture Index (NDMI) as a key remote sensing indicator for quantifying vegetation moisture content and detecting temporal changes in plant water stress. Satellite data from Landsat 5 TM, Landsat 8 OLI, and Landsat 9 OLI-2 were utilized, covering three benchmark years: 2001, 2013, and 2023. All images were pre-processed, atmospherically corrected, and analyzed to ensure comparability across sensors and time periods. The multi-temporal NDMI analysis clearly demonstrates that vegetation moisture has undergone a significant downward trend. Spatial assessment of NDMI classes shows that areas previously categorized as moderate or high-moisture vegetation in 2001 have progressively transitioned into low-moisture or drought-stressed classes by 2013, with this pattern becoming even more pronounced in 2023. These findings indicate that plant water content in the region has decreased markedly, reflecting both reduced precipitation and rising temperatures associated with climate change. Overall, the results confirm that the Absheron Peninsula is becoming increasingly vulnerable to drought, despite being located in a coastal environment. This highlights the necessity for regional adaptation measures, improved water management strategies, and continued monitoring of vegetation health using satellite-based remote sensing tools. These changes in vegetation moisture reflect not only rising temperatures but also increasing pressure on regional water resources. Reduced soil and plant moisture signals growing water scarcity risks, especially in densely urbanized and coastal environments like Absheron, where freshwater availability is already limited.