Society of African Journal Editors

Nigerian Journal of Technological Development

Land use-land cover effects on surface flowing water quality: a statistical approach

Authors: F.J. Ogbozige, M.I. Alfa

Journal: Nigerian Journal of Technological Development

The drainage basin surrounding River Kaduna within the middle stretch is known to have numerous land uses and land covers. Several researchers have investigated the water quality of the river with respect to season and surrounding geology. However, none or little on the water quality of the river have been investigated with respect to land use and land cover (LULC). Hence, this paper examined the water quality of the middle stretch of the river in relation to the different land uses and land covers present using statistical techniques. This was achieved by monthly analyzing 10 physicochemical parameters from water samples collected in 15 sampling stations for a period of 12 calendar months using standard methods. The physicochemical parameters considered include; turbidity, total dissolved solids, pH, chloride ion and electrical conductivity. Others include dissolved oxygen, 5-days biochemical oxygen demand, chemical oxygen demand, total nitrogen and total phosphorus. The different LULC of the watershed obtained via ArcGIS 10.5 were agricultural, vegetation, built-up, industrial, water body and bare surface. Spearman’s correlation analysis between laboratory results and the different LULCs determined via SPSS version 20 revealed that Built-up, industrial, and agricultural land uses contributes significantly to the impairment of River Kaduna water quality as the correlation coefficients between these LULCs and water quality deterioration ranged from 0.0281 to 0.6901. Nevertheless, a significant negative correlation (-0.1482 to -0.5490) exist between vegetation (forest coverage) and water quality deterioration, suggesting that forest cover can mitigate the deterioration of water quality to a certain degree. Keywords: Runoff water, Correlation Coefficient, LULC, Water quality, Sampling frequency