Modelling the impact of land cover and forestry change on the hydrological characteristics of the two streams sub-catchment, Natal Midlands
Duncan, Gabriella Elisabeth
Understanding of the impacts of land cover and the changes thereof on water resources is essential in improving management practices and protecting water resources, particularly in water scarce countries such as South Africa. To determine the impacts of land cover and land cover change on hydrological processes, a small sub-catchment in the KwaZulu-Natal Midlands was modelled. The Two Streams sub-catchment was modelled for both a current (2007 – 2016) and future (2019 – 2028) scenario using MIKE SHE deterministic hydrological modelling software. The aims of the study were to: 1) Assess the ability for MIKE SHE software to model the hydrological cycle of the Two Streams sub-catchment, based on the current scenario set-up. 2) Assess and compare modelled hydrological outputs and characteristics of the dominant land cover types present within the (current scenario) Two Streams sub-catchment: sugarcane (Saccharum officinarum), black wattle (Acacia mearnsii) and riparian vegetation. 3) Determine the impact that a change in plantation forestry from black wattle (A. mearnsii) to Eucalyptus dunnii will have on the hydrological characteristics and hydrological cycle of the Two Streams sub-catchment, using MIKE SHE modeling software (future scenario). Results indicated that the MIKE SHE model was effective at modelling the Two Streams study site. The black wattle plantation was found to use more water through evapotranspiration and experience greater loss in subsurface water supplies in relation to sugarcane and riparian vegetation. In comparing the hydrological characteristics of black wattle and E. dunnii forestry plantations, E. dunnii was the greater water user and experienced greatest reduction in subsurface storage. Before the MIKE SHE model can be used for further modelling on-site, the limitations identified, including those pertaining to the subsurface hydrological characteristics, limited LAI data and limited E. dunnii research, need to be addressed and overcome.
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg In Fulfilment of the requirements for the Degree of Master of Science, 2019
Duncan, Gabriella Elisabeth (2019) Modelling the impact of land cover and forestry change on the hydrological characteristics of the two streams sub-catchment, Natal Midlands, University of the Witwatersrand, Johannesburg, <http://hdl.handle.net/10539/27277>