Understanding the influence of land cover change and landscape pattern change on evapotranspiration variations in Gwayi catchment of Zimbabwe

Abstract

Understanding dynamics in hydrological processes helps to improve water resource management. Climate and land cover changes influence ecohydrological processes. This study sought to assess the influence of climate, land cover and landscape structure dynamics on actual evapotranspiration (ETa). To achieve this, the catchment parameter (w) was parameterised and the relationship between ETa and selected landscape metrics was determined. The ratio of precipitation to potential evapotranspiration was < 1 and the w was < 2, suggesting that land cover changes were more influential to ETa changes than climate variations. Given the low w (1< w < 2), we conclude that the catchment had a low water retention capacity and was sensitive to land cover changes. There was a negative correlation between landscape fragmentation and ETa, indicating that unregulated landscape fragmentation could be adversely impacting catchment water balance. Therefore, promoting initiatives that improve land cover consolidation could enhance water retention capacity.