ELVIC

The Lake Victoria Region

Extreme weather events, like heavy precipitation, heat waves, droughts and wind storms have a detrimental impact on East African societies. The Lake Victoria Basin (LVB) is especially vulnerable: the Red Cross estimates that each year 3000-5000 fishermen perish on the lake due to nightly storms. In addition, the LVB is a global hotspot of future population growth and urbanization. Urban dwellers in this region with low infrastructure are particularly vulnerable to climate extremes, such as urban flooding. As the frequency and intensity of climate extremes is projected to further increase substantially with climate change, so do the risks, with potentially major consequences for livelihoods of people in the LVB. Future climate projections for the LVB are challenged by the complexity of the region. The mesoscale circulation induced by the lake and by the complex orography surrounding the basin, strongly modulate the climate change signal.

Moreover, current state-of-the-art climate simulations over the region parametrise convection, while Convection-Permitting Models (CPMs) have shown a strong added value in representing convection in other regions of the world. Altogether this urges for reducing model resolution to grid sizes of less than 5 km. The computational cost of CPM integrations is currently so high that individual groups can only afford one realization of a possible future climate. Ensemble climate projections at the CPM scale are only possible in internationally coordinated programs such as CORDEX. We therefore propose the CORDEX Flagship Pilot Study (FPS) “ELVIC – climate Extremes in the Lake VICtoria basin” with the overall objective to provide robust climate information on extremes to the impact community.