Scenario-based modelling of ecological security: Integrating land use and climate change impacts in the Lavasanat Watershed

Understanding the impact of land-use and climate change on ecosystem services is crucial for ecological security assessments. This study examines spatiotemporal land-use/land-cover (LULC) changes in the Lavasanat watershed, Tehran, Iran (۲۰۰۰–۲۰۴۰) and evaluates their effects on water yield under different management and climate scenarios.Four LULC scenarios were defined: S۱ (business-as-usual), S۲ (pessimistic), S۳ (realistic), and S۴ (optimistic). Additionally, three climate scenarios (B۱, N, and M) were incorporated into the analysis. The InVEST model was used to simulate water yield variations, while CA-Markov and LARS-WG۵ projected future LULC and climate conditions.Findings indicate a ۱.۹۲-fold increase in water yield in residential areas from ۲۰۰۰ to ۲۰۲۰. The highest water yield was recorded under S۲N (۳۷.۶۴ million m³ watershed-wide, ۳۵.۰۹ million m³ in residential areas), while the lowest was observed under S۴M (۸.۳۳ million m³ watershed-wide, ۷.۳۵ million m³ in residential areas). All scenarios suggest that urban expansion will continue to drive water yield increases while reducing ecologically valuable lands by ۲۰۴۰.These findings highlight the critical role of sustainable land-use planning in mitigating environmental degradation and ensuring ecological security in rapidly urbanizing watersheds.

کلیدواژه ها:

ecological security ، land use/cover changes ، Climate changes ، Water yield ، Lavasanat