ASSESSING THE IMPACT OF SEASONAL VARIABILITY ON SURFACE WATER RESOURCES IN IKPOBA HILL, BENIN CITY, EDO STATE

ABSTRACT

This comprehensive research aims to evaluate the multifaceted impact of seasonal variability on Ikpoba Hill's water resources. Over the past decades, shifts in the timing and duration of seasons have been observed and this have been greatly attributed to notable changes in precipitation and temperature. These changes affect the normal hydrological cycle and thus the water system in general. The project intends to evaluate the impact of seasonal variability on Ikpoba Hill's current surface water sources and their capacities. The methods employed in this study include using the climate modelling software; Water Evaluation and Planning WEAP software to model and analyze how projected changes in meteorological data, that is, weather patterns, including variations in rainfall intensity and temperature affect the water availability in Ikpoba Hill region. Data employed include monthly observed rainfall and temperature as well as yearly peak discharge. Meteorological datasets are obtained from the Nigerian Meteorological Agency and NASA Power Directory. River discharge was gotten from the Benin-Owena River Basin Development Authority (BORBDA) and the climate projection datasets were obtained from the World Meteorological Organisation KNMI Climate Explorer. The historical datasets were from the period 2006-2022 and the projection datasets were from the period 2006-2050. From the results in this research, it is seen that there will be a general decrease in water quantities in all scenarios as temperatures get warmer; a decrease by 35.66% in the year 2030 and further by 24.15% in 2050 based on SSP1-2.6 climate projections. There was a clear indication that the region is highly sensitive to perturbation in climate from the synthetic scenarios. A change in either rainfall, temperature or both could in turn lead to an effect on the surface water yield amounts. Findings from this study may be adopted in the water sector for both long and short-term development planning, evaluation and monitoring of surface water resources, and assessing the vulnerability of the region to these shifts in season that will help the relevant governmental and non-governmental authorities to come up with ideal adaptation measures. Further studies on incorporating other factors such as population, water demands, groundwater, and land use/land cover to assess the impacts of climate change in the region are recommended.