Impact of land use on river systems in Ghana

Abstract

Rivers play significant roles in the provision of water for domestic and industrial purposes. Nevertheless, land use dynamics continue to impact on river catchments which have negative repercussions for river health. This study focuses on land use change in the Okyeman Traditional Area, which encompasses three major river basins namely, the Densu, the Birim and the Ayensu. The study was aimed at investigating causes and impacts of land use change within the three river catchments and how these impacts could be curtailed to safeguard river health and sustainable water supply. Data for the study was derived from analysis of remotely sensed Landsat 7 ETM satellite imagery, and from questionnaire administration. Additional information was culled from the existing literature on land use, land use change, land cover change and related subjects. One major finding was that most of the river basins have undergone massive transformation over the last three decades as a result of various land use activities. The dominant land use types in the basins presently are agriculture, urban development, grazing, residential and transportation and fishing. The study also revealed that mining, indiscriminate waste disposal, water extraction and deforestation for fuel wood and other domestic uses, excessive use of chemical fertilizers and land degradation due to improper agricultural practices are also major land use activities that impact negatively on the river systems. The study concluded that there is the need to streamline land use activities, conserve vital ecosystems like watershed areas and maintain buffers along stream channels as a matter of policy to ensure adequate protection of aquatic fauna and to ensure sustainable water supply.