Impacts of lake Urmia’s hydrological changes on ecological connectivity

This study investigates the ecological consequences of Lake Urmia’s desiccation, assessing impacts on bird dispersal and wetland connectivity by integrating hydrological connectivity metrics. Once spanning 5000 km2 (1980), the lake has transformed into largely exposed salt flats by late 2025 due to anthropogenic diversions, dam proliferation, and climate change, disrupting its keystone role along the Central Asian Flyway for migrants like Phoenicopterus roseus and Pelecanus onocrotalus. Using landscape metrics, we track water surface area loss (to near 0 km2 by late 2025), wetland fragmentation (rising to 65% ± 5%), and Waterbird Assemblage Declines (WAD; to 85% ± 8%) from 1980 to 2025, with no-intervention projections to 2050 showing stabilization at high loss levels. Hydrological connectivity analysis links reduced inflows to substantially narrower dispersal corridors. Temporal linkages (R2 = 0.88–0.95) reveal that each ~ 1000 km2 reduction in water surface area corresponds to a 15–20% increase in WAD, mediated by a 10–15% rise in wetland fragmentation (CFI). This underscores Lake Urmia’s critical role in sustaining ecological connectivity along the Central Asian Flyway and highlights the elevated risk of delayed population declines among migratory species due to the severe habitat thresholds crossed by 2025. Findings of this research emphasize the urgent need for targeted inflow restoration, prioritizing the southern arm where residual water patches persist, to reconnect fragmented wetlands, restore hydrological connectivity, and mitigate extinction debt along the Central Asian Flyway.