Analysis of catchments response to severe drought event for improved water resources
Drought is a natural hazard that is a normal part of climate in all regions of the world. It can result in serious economic, social and environmental impacts, if not properly managed. Consequently, there is a need to take precautionary measures to prevent problems associated with mismanagement of drought events. In this study, two catchments namely the Grand River South East and River Cascade of Grand River North West, have been analysed so as to better understand their response to dry spells. Three methods were initially selected namely; Flow Duration Curve, Low Flow Frequency Curves and the Base Flow Index. The second step in this study was to perform more in depth drought. The Run Sum analysis method and the Low Flow Frequency Analysis using Weibull distribution were used to characterise the drought event. The analyses firstly noted that the two catchments under study responded differently to rainfall events. The Low flow frequency analysis was used to identify a threshold value, below which dry conditions were considered. The run sum analysis method was a sound method which indicates in advance the coming of dry spells, and this can help in better management of water resources, especially for an island.
Keywords: Drought, Low Flow analysis, Run Sum Analysis, Island, Drought