Impacts Of Land Use/Cover Change On Water Quality In Lake Bosomtwi Basin Of Ghana..

ABSTRACT Land use/cover alteration within lake basins is occurring at accelerated rate most importantly in developing countries like Ghana. Anthropogenic activities (livelihood change, population growth, agricultural intensification and practices) and natural factors like seasonal variations are in most situations the major cause. To examine the effects of land use/cover on the physico-chemical and biological properties of Lake Bosomtwi, satellite images of the Lake’s watershed covering the study periods (1990, 2000 and 2010) were obtained and processed to determine the land use /cover changes that have taken place over the study period. Samples of water and soil were collected from December 2013 to May 2014 from seven different sites within the lake Bosomtwi watershed for investigation. All physical water quality parameters were measured in-situ. The observed temperature of the Lake water was relatively high varying from a minimum of 27.6 ˚C to 33.6 ˚C, with a mean value of 30.4±1.5 and an average pH value (9.0±0.6) depicting a highly alkaline Lake water. The result showed salinity range of 0.40 ppt to 0.56 ppt which was slightly above the WHO standard of 0.5 ppt for drinking water. Conductivity values were also generally high with a mean value of 1352.7±27.6 µS/cm. The mean values recorded for the other physico-chemical parameters were; Turbidity 6.1±4.6 (NTU), Apparent Color 67.8±22.4 pt.co, TDS 645.6±48.1 mg/L, TSS 6.8±5.3 mg/L, DO 7.5±0.9 mg/L, BOD 3.7±1.0 mg/L, COD 98.9±10.8 mg/L, Nitrate 1.3±0.3 mg/L, Nitrite 0.01±0.02 mg/L, Phosphate 0.40±0.19 mg/L and Ammonium 0.018±0.017 mg/L. All the studied biological indicators were significantly high compared to the WHO standard for good water quality making the Lake water unfit for most domestic purposes without partial treatment. The result from the soil analysis showed that, soil EC varied from 176 to 454 µs/cm, pH 6.7 to 8.6, total coliform and E.coli ranged from non-detectable  ABSTRACT Land use/cover alteration within lake basins is occurring at accelerated rate most importantly in developing countries like Ghana. Anthropogenic activities (livelihood change, population growth, agricultural intensification and practices) and natural factors like seasonal variations are in most situations the major cause. To examine the effects of land use/cover on the physico-chemical and biological properties of Lake Bosomtwi, satellite images of the Lake’s watershed covering the study periods (1990, 2000 and 2010) were obtained and processed to determine the land use /cover changes that have taken place over the study period. Samples of water and soil were collected from December 2013 to May 2014 from seven different sites within the lake Bosomtwi watershed for investigation. All physical water quality parameters were measured in-situ. The observed temperature of the Lake water was relatively high varying from a minimum of 27.6 ˚C to 33.6 ˚C, with a mean value of 30.4±1.5 and an average pH value (9.0±0.6) depicting a highly alkaline Lake water. The result showed salinity range of 0.40 ppt to 0.56 ppt which was slightly above the WHO standard of 0.5 ppt for drinking water. Conductivity values were also generally high with a mean value of 1352.7±27.6 µS/cm. The mean values recorded for the other physico-chemical parameters were; Turbidity 6.1±4.6 (NTU), Apparent Color 67.8±22.4 pt.co, TDS 645.6±48.1 mg/L, TSS 6.8±5.3 mg/L, DO 7.5±0.9 mg/L, BOD 3.7±1.0 mg/L, COD 98.9±10.8 mg/L, Nitrate 1.3±0.3 mg/L, Nitrite 0.01±0.02 mg/L, Phosphate 0.40±0.19 mg/L and Ammonium 0.018±0.017 mg/L. All the studied biological indicators were significantly high compared to the WHO standard for good water quality making the Lake water unfit for most domestic purposes without partial treatment. The result from the soil analysis showed that, soil EC varied from 176 to 454 µs/cm, pH 6.7 to 8.6, total coliform and E.coli ranged from non-detectable