The impact of land use and land cover changes on the Nkula dam in the middle shire river catchment, Malawi

Abstract

Land use and land cover changes over a 26-year period for the middle ShireRiver catchment, Malawi, in southern Africa, were assessed using geographicinformation systems (GIS) and remote sensing techniques. The catchment areaunder study was divided into two sections, western and eastern sides of the ShireRiver. High rate of deforestation averaging 4.3% per annum was observed and morepronounced in the western side of the river. Rapid population growth and increasein gross domestic product (GDP) are identified as the major drivers of deforestationand forest degradation due to clearing of vast fields for agriculture, land expansionfor urban settlement, and cutting down of trees for wood fuel energy. Deforestationin the middle Shire River catchment has resulted into increased soil loss througherosion causing huge accumulation of sediment at the Nkula B Hydroelectric PowerDam downstream and, consequently, causing serious problems with generation ofhydroelectricity. Frequent droughts and floods in the area have drastically affectedcrop production forcing people into cutting down of trees for charcoal as a liveli-hood strategy. Combined techniques such as GIS, remote sensing, and socioeco-nomic factors used in this study could be applied in other places where similarchallenges occur.