Evaluating the Effect of Adaptation Policies on Crop Yield, Economic Growth and Water Resources: A DPSIR-Based Analysis for the Niger River Basin Under Shared Socioeconomic Pathways-Representative Concentration Pathways (SSP-RCPS) (2014–2100)

Climate change poses significant threats to agricultural productivity and water resources in vulnerable regions like the Niger River Basin (NRB). This study evaluates the impacts of climate change and adaptation strategies on crop yield, economic growth, and water resources in the NRB section in Nigeria under five Shared Socioeconomic Pathway-Representative Concentration Pathway (SSP-RCP) scenarios (2014–2100). Using an improved DPSIR (Driving Forces, Pressures, States, Impacts, and Responses) framework implemented in Vensim PLE 10.2.2, we integrated climate projections, agronomic responses, and policy interventions to assess system dynamics. Three adaptation pathways which include irrigated cropland expansion, afforestation, and mixed approaches were evaluated, revealing that aggressive interventions could restore yields to low-emission (SSP1-1.9) levels but at high economic and ecological costs in higher nitrogen pollution, but sufficient economic and ecological tradeoffs exist when adaptation pathways is combined with mitigation effort, with improvement in water use and nitrogen remediation. Multi-objective optimization prioritized forest-based strategies as optimal for balancing agricultural and ecological goals. These findings underscore the critical need for integrated mitigation-adaptation policies to enhance climate resilience in the NRB.