Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Article Title: Experimental Effects of Sand Dams on the Quality of Water and Rate of Evaporation: A case study in the Nabogo Basin
by Samuel Snr Adjei Sao, Kwaku Amaning Adjei, Emmanuel Kwame Appiah-Adjei, Samuel Nii Odai

Abstract:
There are prolonged periods without rains in the savannah regions of Ghana and this makes it difficult for inhabitants to get access to water all year round and so have adapted to the use of dugouts. These dugouts are exposed to the atmosphere and are subjected to evaporation which causes them to dry out mostly during the dry season, the period when they are needed most. The study focused on determining how effective sand dams are in the reduction of evaporation and how the quality of water can be improved. It involved the construction of a laboratory scale version of a sand dam; this was filled with a river sand and saturated with water (with the water table below the surface) and the rate of evaporation was determined and compared with another setup filled with only water. The quality of water was also determined before and after passing through the sand. Evaporation for the period was 51% lower in the sand dam than the open water storage with 77% of the days recording lower evaporation rates in the sand dam model. There were days that the evaporation in the Sand dam model were higher and this was due to suction and diffusion of tiny films of water from the evaporation surface and as a result of capillary action enhanced by the smaller saturated pores. Turbidity, Total Dissolved Solids, Faecal and Total Coliforms levels were reduced after the water samples were passed through the sand media since the microorganisms that are attached to particles that are dissolved or suspended in the water were trapped by the sand and as a result reduces their level after filtering. Sand dams can be used to improve the quality of water and can help reduce evaporation during the dry season where there are practically no rains.

Keywords: Evaporation, Sand Dams, Drought, Dugout, Water Quality

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