Land use and land cover (LULC) have been and still changing, through human activities, creating variability in hydrological cycle. This paper investigates the hydrological impacts of LULC changes on water balance in the White Volta Basin located in the West of Africa using the Soil and Water Assessment Tool (SWAT). Two LULC data for 1990 and 2006 and two plausible scenarios of land use change were evaluated. Results show a link between land cover and the hydrologic response with a decrease in land cover corresponding to decrease in surface water and base flow and increase evapotranspiration (ET). The results indicated that different LULC contributed to various effects in annual water yield and ET. The results also indicate the capability of the SWAT model to be used in the West African subregion even though there are data limitations associated with the model in West Africa. Overall, the model results support the existing efforts of Volta Basin water resource managers to protect the area along the Volta river against farming and indicate that additional emphasis should be placed on improving land management practices. Water and Environment Journal. Print ISSN 1747-6585 Land cover changes and water balance components A. Awotwi et al. 6 Water and Environment Journal (2014) © 2014 CIWEM. Land cover changes and water balance components A. Awotwi et al. A. Awotwi et al. Land cover changes and water balance components 7 Water and Environment Journal (2014) © 2014 CIWEM. A. Awotwi et al. Land cover changes and water balance components

An assessment of some heavy metals concentrations in lettuce in irrigated with waste water in Tamale Metropolis in Ghana has been carried out. Analysis of water and lettuce samples revealed that the mean concentrations of Fe, Mn, Cu, Zn, Cd and Pb in lettuce were 0.436, 0.345, 0.068, 0.017, 0.04 and 0.038 mg/L and 0.167, 0.163, 0.104, 0.127, 0.142 respectively. With exception of Mn and Cd, the concentrations of heavy metals in the irrigation water, irrigated soils and irrigated lettuce, were within the FAO recommended levels. The mean concentrations of nutrients (NO 3 -N, SO 4 and PO 4 -P) in the wastewater-irrigated lettuce, and well water-irrigated lettuce were 15.36, 0.88, 0.28 and 19.09, 1.117, 0.0573 respectively. Though, heavy metals concentrations in the lettuce were low, regular monitoring are required to prevent heavy metal accumulation with their attendant health implications in the consuming public.

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The rational for the study was to assess the levels of endocrine disrupting trace metals in River Samre. The levels of Mercury ranged from 0.01 to 0.02 mg/l (mean of 0.006 mg/l), whiles cadmium levels ranged from 0.002 to 0.011 mg/l (mean of 0.01 mg/l). The high levels of Hg and Cd may have adverse effects on the endocrine system of inhabitants who drink directly from the river without treatment. High levels of mercury and cadmium might be caused by the activities of a Timber and Plywood Company located close to the river and the underlying bedrocks of the area exposed as a result of human activities such as farming. The concentration of lead was below detection limit (<0.005 mg/l) but that of Arsenic ranged from 0.001 to 0.007 mg/l (mean of 0.005). Health risk assessment conducted shows that the risk associated with exposure to these metals for now are low. Continuous water quality monitoring is recommended to help protect the resource and also to safeguard human health.

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