Future eco-hydrological dynamics: Urbanization and climate change effects in a changing landscape: A case study of Birmingham's river basin

The global challenges of water availability and quality are driven by land use and climate changes, further exacerbated by global warming. Altered Land Use and Land Cover (LULC) due to urbanization, deforestation, and agriculture triggers many environmental issues to eco-hydrological systems, which are already profoundly impacted by shifting climate patterns. The Upper Black Warrior River Basin in Birmingham, Alabama, is a prime example of how converting forests into urban areas impairs water quality and increases surface runoff due to impermeable surfaces. This study delved into the temporal and spatial alterations in eco-hydrologically relevant flows, considering individual and combined climate change scenarios and LULC transformation. The Soil and Water Assessment Tool (SWAT) served as the modeling platform, calibrated (2016–2022) and validated (2011–2015) at a daily time scale. Five distinct scenarios were crafted to portray eco-hydrology's past, present, and future responses (runoff and river nutrients) to climate and LULC variations. The model demonstrated strong performance for discharge and predicted increased runoff in future periods, which is attributed to the anticipated warmer, wetter winters and hotter, drier summers characterized by more intense rainfall events. Notably, the study unveiled the adverse impact of climate change on monthly nitrates leaching into surface runoff, with the lowest levels predicted during May to September coinciding with reduced precipitation. Conversely, human activity positively impacts runoff, especially in FMC, which has a higher deforestation rate (42.8%) and increased runoff compared to VC. The study also emphasized the significant link between flow and nutrient concentration, highlighting the dominant role of nonpoint sources in contributing to these inputs. These findings have significant implications for local stakeholders, necessitating considering the potential consequences of integrated climate change and urbanization on eco-hydrology. Effective management strategies, such as improved land use practices and reduced nutrient leaching, must be implemented to minimize these impacts.