Integrated Water Resources Management Modelling for Climate-Resilient Agricultural Development in the Benue River Basin

This study develops an integrated water resources management model for the Benue River Basin that explicitly addresses climate change resilience requirements for agricultural development, contributing an original planning framework for one of Nigeria's most important agricultural river systems. The Benue River Basin supports the agricultural livelihoods of over 10 million people in Benue, Plateau, Adamawa, Taraba, and Kogi States, providing water for irrigation, livestock, fisheries, and domestic use. Climate change is projected to increase hydrological variability in the basin, creating significant uncertainty for agricultural development planning. This study develops a coupled basin-scale hydrological-agricultural-economic model using WEAP water evaluation and planning software integrated with a crop production model and economic welfare optimisation module. The model is parameterised using 40 years of hydrological data from 15 river gauging stations, agricultural survey data from 1,500 farm households, and institutional data from the Lower Benue River Basin Development Authority. Climate change scenarios from CORDEX-Africa are integrated as model forcing. Infrastructure development scenarios including new irrigation scheme development, water storage construction, and flood management investments are evaluated against climate resilience metrics. Findings reveal that conventional water infrastructure development plans for the Benue basin will face 25 to 45 percent performance shortfalls under mid-century climate projections without adaptation. Flexible infrastructure designs with adjustable operating rules perform significantly better than fixed-design conventional approaches across the range of climate futures. The study contributes an original climate-resilient IWRM model for the Benue basin and recommends its adoption as the planning framework for LBRBDA.

Keywords: integrated water resources management, Benue River Basin, climate resilience, agricultural development, Nigeria.