Assessment of the Impact of Rainfall Variability on Rainwater Harvesting as an Alternative Domestic Water Supply in the Coastal Areas of Southeastern Nigeria
Authors: Ubuoh EA, Ogbonna PC, Egbe CA
This paper assessed the effects of rainfall variability on domestic rainwater harvesting for human consumption as an alternative source of water supply in the coastal areas of Akwa Ibom State, Nigeria. To achieve this, rainfall data for 20 years (1989-2008) was collected from meteorological stations in Akwa Ibom State. Rainfall variation was determined using the coefficient of variation of the monthly rainfall data. Rainwater harvesting potential was evaluated using supply side approach (SSA). The estimation was done by multiplying the iron roof area (150 m2) with a coefficient (0.9). The results indicated that monthly rainfall variability ranges between 18.39 mm -378.63 mm, with September recording the highest mean value and January had the lowest mean value. Mean annual rainfall variability ranged between 145.6-440.7 mm with 1990 having the lowest annual mean value and 1993 having the highest annual mean. There was a gradual increase in rainfall in April and dropped in July and its peak in September with the maximum storage capacity of 98 m3 (983,000 liters harvested rain. The result further indicated that the total demand line for rainwater consumption was 18,000 liters above the 20 liters United Nations Standard for rural communities for collecting and storing water for potable and non-potable uses. It is then recommended that rainwater harvested should pass through proper treatment with emphasis on operation and maintenance (O&M) for quality assurance due to incessant gas flaring in the region.
Affiliations: Department of Environmental Management and Toxicology, Michael Okpara University of Agriculture, Umudike, PMB 7267, Umuahia, Abia State, Nigeria
Keywords: Rainwater Harvesting, Rainfall Variability, Rainwater Potential, Coastal Region, Sustainability
Published date: 2020/06/30