Effect of land use and land cover changes on water quality in the Nawuni Catchment of the White Volta Basin, Northern Region, Ghana

摘要

Abstract Pollution of freshwater resources is gaining global attention due to increasing freshwater stress and scarcity. This study assessed land use and land cover changes (LULCC) in the Nawuni Catchment of the White Volta Basin and how the change affects water quality in the area. Satellite images from Landsat Thematic Mapper and Landsat 8 Operational land imager of the Nawuni Catchment of the White Volta Basin were acquired and used for this study. These images were analysed to ascertain the influence of land use and land cover changes on water quality parameters such as turbidity, ammonia and total coliform counts for a 10-year period (2007 to 2017). The results of LULCC revealed an increased expanse of grassland/farmland (4.1%), settlement (0.1%), bare land (9.4%) and closed savannah (1.2%), whilst opened savannah (14.7%) and water body (0.1%) recorded a decreasing trend. The study showed an increase in the levels of turbidity and ammonia and a decrease in total coliforms over the study period (2007 to 2017). The study also revealed a positive relationship between LULC categories and water quality parameters, implying that LULCC contribute to the change in water quality in the area. The study therefore recommends frequent water quality monitoring and LULC planning and management to curb pollution of the river basin.