Spatial and temporal variation in rainfall and streamflow – Dzalanyama Catchment, Malawi

Abstract

Mixed research design methods were used to assess the spatio-temporal variation of rainfall and streamflow in the Dzalanyama Catchment, Malawi. Trend analysis was carried out using the Mann-Kendall trend test and showed that only three stations had statistically significant trends at the 5% level in rainfall at different time scales. Three out of five stations indicated statistically significant increasing trends at 5% level on streamflow analysis. The streamflow analysis results indicated that the warm-wet season has high mean values, the highest being 16.95 mm/month (February). The cool-dry season had lower mean values, the lowest being 0.45 mm in September. The coefficient of variation was higher in the wet than the dry months, its highest being 123% in December and the lowest 58% in September. The variability at various stations might arise from factors associated with human activity, and thorough knowledge and analysis of rainfall and streamflow regimes on different time scales are necessary for water resource management to mitigate floods and droughts. HIGHLIGHTS Assessed the variation of rainfall and streamflow in the Dzalanyama.; The mixed research design method confirmed the variation of rainfall and streamflow.; Rainfall and streamflow varies with seasons.; Much of the variations are attributed to human induced activities.;

Keywords

• dzalanyama catchment
• coefficient of variation (cv)
• integrated water resources management (iwrm)
• mann-kendall