John Corbett Ph.D., aWhere, Inc. Chief Science Officer - September 2017
Food Security Check: A 2017 Look at Sahel Region (Burkina Faso through Niger and northern Nigeria)
The concept of ‘pocket droughts’ is an emerging convention for relatively confined areas of persistent drier-than-normal conditions during the growing season. Such pockets are rarely noticed by the major famine monitors but their formation is becoming more frequent and the human misery they cause is becoming more significant. Although urban populations are growing throughout sub-Saharan Africa, the majority of people continue to earn their livelihoods farming and most live on patches of land smaller than 3 hectares. Food production for local consumption is needed by the farm families and food insecurity is a growing concern – and this is especially true in the more marginal lands.
To read about PET (Potential Evapotranspiration) see aWhere’s blog about The Thirsty Atmosphere, and for more about the information leveraged to produce the analytics and maps in this blog - see our earlier blog about aWhere’s Big Data Asset.
Fig 1: Growing conditions (P/PET) across Burkina Faso in the west through NE Nigeria in the east in 2017 were once again characterized by great variability:
The areas circled in the burnt orange color demark areas that typically receive good rains during this period – but not during this crucial growing season period in 2017. Yes, rain fell and it is not a deep drought – but farmers in these areas expect sufficient rain through August and their agronomic practices reflect this expectation: higher planting densities than in the more semi-arid areas to the north. These practices create an asymmetrical penalty for these farmers in Fdry years as the higher plant populations draw down the soil moisture rapidly, and the loss of productivity is measured in 1,000s of kg/hectare. Farmers in the more semi-arid north plant lower densities, and in drier than normal years (areas circled in red), their yield decreases. The overall production, however, shows decreases of 500-1000 kg/hectare. This is because these semi-arid fields only expected 1,500 kg/ha as opposed to 4,000-5,000 kg/ha in the well-watered areas.
Droughty conditions during the reproductive phase of grain crop growth can irreversibly and negatively impact crop yield. This variability in the rainy season is becoming all too normal. The economic impact can have far reaching influence as farmers are less likely to invest in the next season after a poor one as their resources would already be strained.
Looking closer at the situation in Burkina Faso, figures 2 and 3 show the 30-day P/PET situation, first for the period July 15 – August 13, and then 2 weeks later, July 26 – August 25. This persistent dry area, timed such that this period overlaps with the reproductive growth stage of most grain crops planted late May through early June, sends a signal for poor yields in these areas. A quick assessment against population data show that about 1.5 million people live in the area colored orange in Figure 2 (data from 2014) some of whom are of course urban dwellers as this area approaches eastern Ouagadougou, the capital city. Note: for the area of Burkina Faso, aWhere processed >3,200 weather station’s worth of data.
This view of a 2017 pocket drought within Burkina raises several interesting questions: will there be a price rise in basic food stuffs in Burkina and if so, when? What about imports, will they increase? The political geography of a land locked small country in west Africa are complex, and episodic food shortages are becoming all to normal. Monitoring and managing risk is a growing concern.
Figure 2: Zoom into Burkina Faso, P/PET for the period 15 July – 13 August 2017:
Figure 3: Zoom into Burkina Faso, P/PET for the period 26 July – 25 August 2017: