SPATIAL HETEROGENEITY OF GREENNESS IN ALMATY ACROSS DISTRICTS: COMPARING TOTAL AND ROAD-PROXIMATE URBAN GREENNESS (M²/PERSON) USING A SUMMER 2025 NDVI COMPOSITE

Abstract

The aim of this study is to quantify the spatial heterogeneity of greenness in Almaty across eight administrative districts and to compare total greenness (within administrative boundaries) with road-proximate urban greenness constrained to the road-buffer-defined urban proxy, using area- and per-capita indicators (m²/person). The methodology is based on Sentinel-2 L2A data (Copernicus Browser) and a summer NDVI composite for June-August 2025 constructed as the pixel-wise median of eight low-cloud scenes. Greenness was mapped using NDVI thresholding (primary threshold NDVI > 0.30; sensitivity analysis for NDVI > 0.25 and NDVI > 0.35). Road-proximate urban greenness was operationalized as green pixels located within a 500-m buffer around the street network (QuickOSM), followed by district-level zonal statistics in QGIS; per-capita values (m²/person) were computed using official population statistics as of 1 July 2025 (Bureau of National Statistics). The originality and value of the study lie in a reproducible separation of “territorial” versus “urban-fabric” greenness for a city whose administrative extent includes large natural landscapes, improving interpretability and reducing upward bias in district comparisons. Results show that for NDVI > 0.30, Almaty’s total green area equals 591.45 km² (254.94 m²/person), whereas road-proximate urban greenness equals 442.05 km² (190.54 m²/person), representing 74.7% of total greenness by area. At the district level, road-proximate urban greenness ranges from 49.24 m²/person (Almaly) to 476.39 m²/person (Medeu), a 9.67-fold disparity; the top three districts are Medeu, Nauryzbay, and Turksib, while the lowest values occur in Almaly, Auezov, and Zhetysu. District rankings are robust to the NDVI threshold choice (0.25/0.30/0.35).