The geography of Africa is varied. Surrounded by the Mediterranean Sea, Atlantic Ocean and Indian Ocean, it features deserts, tropical rainforests, highlands and lakes.
Climate Classification
Under the Köppen-Geiger climate classification map, the continent of Africa features a range of climate types.
A large part of the northern region of Africa is dominated by the Sahara desert, spanning an estimated 3000 miles east-to-west and about 800 miles north-to-south.
Where the Sahara desert is, the area is dominated by an arid, desert, hot climatic condition. Parts of the southern bit are also classified by this desert-like climate coinciding with the Kalahari desert.
Beyond the desert-like conditions, the middle of the continent that sits surrounding the equator features a tropical climate and tropical rainforests. The ecological break of Africa is telling of this too.
An estimated 2 million km^2 of Africa is covered by rainforests (Mayaux et al. 2013). This is only second to the Amazonia that covers 6 million km^2 (Butler 2019).
Precipitation
In terms of precipitation, North Africa, South Africa and the horn of Africa receive the least amounts. The wetter areas have a hot semi-arid climate rather than a hot desert climate.
Most studies attribute the seasonality in rainfall to the migration of the intertropical convergence zone (ITCZ) as it migrates north migrates north towards sub-Saharan Africa by August and then south into south-Central Africa by March, bringing with it large amounts of rainfall. [Note that while the ITCZ as an explanation for seasonal rainfall in Africa is largely accepted there are others who argue that the ITCZ is an insufficient explanation, see Nicholson (2018).]
Average annual rainfall conceals the variability of rainfall. Fortunately the figure above captures that in the smaller add-on map and illustrates that not only are Northern Africa and southern bit with the Kalahari desert the driest parts, they are also the areas with the highest variability in rainfall.
What do these maps of Africa not tell us?
Maps depict a certain truth but also shield us from other information that is important for a study in water, food and development.
Couple of things worth nothing but is concealed on the maps:
The effects of climate change are not well captured: while El Nino cycles are naturally occurring and have been studied, the effects of climate change are more uncertain with research predicting that droughts will become more frequent and severe, rainfall more frequent and intense.
Alternative sources of water: it is normal to have wet and dry periods, most countries/people have also found ways of adapting and developing resilience against dry spells – an exploration into how/why/their effectiveness would prove valuable.
Promise of groundwater: with climate change, groundwater discharge has actually increased over time and this could prove useful as a potential source of water for domestic and agricultural use.
Why is this important?
Most agriculture in Africa is rain-fed, which makes the mere presence of rain important. Cultivation of crop is limited by water availability.
A study by Conway et al. (2015) published in Nature Climate Change explains the strong interdependence between climate and the water, energy and food. Impact models suggest that a 20% fall in annual rainfall is expected in southern Africa, decreasing water availability and crop yield.
In Middle Eastern and North Africa (MENA), the agricultural sector accounts for 25-40% of the labour force and more if we include those in agriculture-related sectors (xxx).
Agriculture is is not just a source of income and livelihood, it is also important for consumption. The poor whose income shares are largely spent on food also have their sources of income (their livelihood) tied to agriculture often found in poor, rural areas.