ABSTRACT

This chapter investigates the spatial and temporal variability of streamflow and rainfall in the Incomati basin. Long term rainfall records were analysed using descriptive statistics, annual anomalies, and trends. Change points were identified using the Pettitt test, and monthly and annual trends were identified using the Spearman test. Significance of change points and trends were assessed with F and t tests. Furthermore, the Indicators of Hydrological Alteration approach was used to further describe the streamflow regime in selected streamflow gauges in the catchment, and identify trends in key hydrological indicators. The trends were mapped across the basin, and were compared with rainfall trends, as well as historical and current land use. The links between observed changes and potential drivers were discussed, and well as the implications of this for water management in the basin.