СOMPREHENSIVE ASSESSMENT OF URBAN GREEN SPACES IN THE CITY OF АKTAU BASED ON MULTISPECTRAL SATELLITE DATA

Abstract

The city of Aktau, located in the arid coastal zone of the Caspian Sea, is characterized by serious environmental challenges, including freshwater scarcity, soil salinization, and high solar radiation. Under such conditions, effective greening requires scientifically grounded solutions. This study aims to conduct a comprehensive assessment of the state, structure, and spatio-temporal dynamics of urban green spaces in Aktau using remote sensing (RS) methods and multispectral satellite data from 2015 to 2024. Based on Sentinel-2 and Landsat 8-9 imagery, an analysis of vegetation indices (NDVI) was carried out. The proposed approach enables not only mapping the density of vegetation cover but also identifying areas of ecological vulnerability and inequality within the urban environment. The results reveal pronounced spatial fragmentation of the city’s green framework, dominance of xerophytic flora, and significant intra-urban environmental disparities. Decreased NDVI values were recorded in peripheral and industrial areas, associated with limited irrigation, weak institutional regulation, and socio-economic gradients. In contrast, the highest NDVI values were observed in central and coastal districts, while vegetation degradation was noted in industrial and newly developed residential zones. The study included over 80 green infrastructure sites, comprising more than 138 000 specimens of trees and shrubs, predominantly drought-tolerant taxa. Elements of environmental inequality were identified between neighborhoods in terms of greening levels and access to green areas. The study emphasizes the need to shift towards a systemic spatial model of urban greening, integrate digital monitoring platforms, and strengthen public participation. The findings and proposed methodological framework can be applied to ensure sustainable green infrastructure management in other arid cities across Kazakhstan.