Spatiotemporal analysis of artificial nighttime light pollution and environmental interactions in a rapidly urbanizing megacity
摘要
Artificial nighttime light pollution (ANTLP) poses significant threats to ecological integrity, human health, and urban sustainability in rapidly urbanizing megacities. However, comprehensive understanding of spatiotemporal ANTLP dynamics and their environmental associations remains limited in developing regions. This study investigated: (a) spatiotemporal patterns and statistically significant hotspots of ANTLP; (b) associations between light pollution and urban development, topographic, hydrological, thermal, and demographic factors; and (c) co-occurring environmental changes in vegetation health, surface water extent, and thermal conditions in Dhaka, Bangladesh, during 2014–2023. Integrated VIIRS satellite data with Landsat-derived spectral indices (NDVI, NDBI, NDWI), MODIS nighttime land surface temperature, SRTM topography, and demographic data were analyzed. Getis-Ord Gi* hotspot analysis identified spatial clustering patterns, while principal component analysis (PCA) and correlation analysis quantified environmental associations. Mann–Kendall trend tests and permutation testing assessed statistical significance of temporal changes. ANTLP intensity increased from 0.56 to 143.25 nW/cm2/sr (7.2% annual growth; Mann–Kendall Z = 3.21, p = 0.0013). Hotspot coverage expanded significantly from 15 to 42% of the metropolitan area (permutation test p = 0.0091). Building proximity exhibited the strongest association with ANTLP (r = 0.97), followed by population density (r = 0.85). PCA identified five components explaining 89% of ANTLP variance. Areas of high ANTLP co-occurred with vegetation decline (NDVI: − 0.22 to − 0.55), surface water reduction (NDWI: − 0.37 to − 0.54), and 2.3 °C nighttime temperature elevation. These findings suggest that ANTLP serves as a spatially explicit indicator of broader urbanization pressures. The results provide evidence-based frameworks for sustainable urban lighting policies, including zoning regulations, buffer zone establishment around water bodies, and smart lighting implementation in rapidly developing cities.
Graphical Abstract