Impact of land-use/cover change on water quality in the Mindu Dam drainage, Tanzania

Abstract

Water pollution caused by land-use/cover change is one of the most pressing problems facing both industrialized and developing countries. Freshwater quality deterioration suggests the collective outcomes of natural courses and alterations in land-use/ cover. Understanding the correlation among land-use/cover and water quality parameters is vital for future water quality management. In this work, land-use/cover pattern and its effect on water quality in the Mindu Dam drainage area were analysed using Remote Sensing (RS) and Geographical Information System (GIS) techniques together with cellular automata–Markov model. The land-use/cover images between 1990 and 2020 were used to assess historical and spatial change of land-use/ cover change, and projected for 2030 and 2040. We discovered that the dynamics of land use and land cover during the study period were significant. A strong correlation was revealed between changes in the land-use/cover and water quality parameters. Furthermore, a strong correlation exists between cultivated land and measured nutrient (nitrate and phosphate) and chlorophyll-a concentration. The natural vegetation buffer around Mindu Dam should be sufficient to prevent long-term water quality degradation from agricultural runoff in order to manage water quality sustainably. Therefore, land-use/cover management practices must be considered for sustainable resource management and water quality monitoring.