Mangrove dynamics under anthropogenic influence: built-up expansion and urban proximity along the Maharashtra coast

Mangrove ecosystems along the Maharashtra coast are increasingly affected by swift coastal urban development; however, the spatial processes contributing to their degradation are inadequately comprehended. This study examines the spatiotemporal loss of mangroves and the expansion of built-up environments from 2004-2024, analyzed across four quinquennial periods (2004–2009, 2009–2014, 2014–2019, Citation2019–2024), with particular emphasis on examining the spatial distribution of mangrove loss relative to built-up areas. Multi-temporal data were examined through supervised classification, post-classification change detection and an urban proximity-based degradation analysis methodology. The findings reveal significant mangrove loss concurrent with urban expansion, whereas the direct transformation of mangroves into developed land constitutes a small but considerable portion of total degradation; importantly, over 99% of mangrove loss occurred within 250 m of urbanized zones. These findings reveal a pronounced spatial concentration of mangrove loss in areas where urban development and mangrove ecosystems coexist. The results demonstrate the utility of proximity-based analysis for identifying spatial patterns of co-occurrence between urban development and mangrove loss in increasingly urbanized coastal environments.