Assessing the impacts of water bodies encroachment on urban land surface temperature

Water bodies play a crucial role in controlling urban heat by acting as a sink and enhancing evaporative cooling. However, rapid urbanisation in India has led to the progressive encroachment and shrinkage of water bodies, which threatens the urban thermal environment. In this study, we investigate the impact of urban water body encroachment on surrounding temperature using multidecadal Landsat-derived land surface temperature (LST) data at 30 m spatial resolution and water body datasets. The LST of Water bodies and surrounding urban areas within their vicinity are estimated to assess spatiotemporal changes in LST. Our results reveal a substantial increase in LST in urban regions surrounding water bodies in recent decades, indicating a decline in their local cooling effectiveness. Furthermore, encroached water bodies exhibit a pronounced rise in surface water temperature than non-encroached water bodies. The warming of both water surfaces and adjacent urban areas highlights the compound thermal impacts of water body encroachment. The findings indicate that the loss of urban water bodies due to encroachments contributes to the warming of urban areas. The study underscores the importance of protecting and restoring urban water bodies as effective nature-based solutions for mitigating rising urban temperatures and enhancing climate resilience in rapidly growing urban cities.