Drought Processes in Current and Future Climate and Implications for Irrigation and Resilient Food Systems in Malawi

Malawi’s climate is no exception to frequent droughts, a characteristic feature of the southern and eastern African climate. The study first examines drought characteristics and associated atmospheric circulation patterns in observations, reanalysis, and present-day climate simulations. Drought climatology is generally uniform across Malawi, but differences is drought timing and simultaneous dry-wet anomalies suggest different drought drivers between the north and south. Different atmospheric circulation patterns during drought years in the two regions highlight the dynamical pathways through which drivers of variability – including El Niňo Southern Oscillation (ENSO) – produce drought conditions in the two regions. CMIP5 models simulate drought processes over Malawi with notable biases in the drought climatology, and inconsistencies in associated mechanisms particularly those linked with ENSO.
The second component of the study examines droughts in climate projections and performs hydrological simulations to examine hydrological responses to climate variability and change, and implications for irrigation across five river basins in the Lake Malawi–Shire River Basin. Drought frequency is projected to increase across Malawi as are drought severity and intensity, reflecting projected changes in temperature and precipitation. Hydrometeorological processes across all five basins show high sensitivity to climate variability and change. High streamflow responses to changes in precipitation means that episodic spikes in irrigation water demand (IWD), resulting from meteorological droughts, usually coincide with hydrological droughts. IWD is projected to increase across all five river basins. The most pronounced increase is in the Shire River basin where a significant reduction in streamflow reliability is also projected.
Finally, the study explores climate risk perceptions in relation to irrigation at the national, local government, and grassroots levels. There is increasing recognition of climate risk in policies, but less attention is drawn to risks for irrigation, although farmer communities appreciate climate risks for irrigation through various encounters. Dominant narratives risk continuous framing of irrigation as immune to climatic shocks but slowly convergent views around climate risks for irrigation and a responsive policy environment provide opportunities for a systematic paradigm shift towards climate-smart irrigation.