Global Information and Early Warning System
INCREASED PRECIPITATION IN LATE JULY HAVE IMPROVED CROP PROSPECTS WHICH HOWEVER REMAIN UNCERTAIN IN SOME COUNTRIES
Following generally adequate rains in May and June, except in Burkina Faso which registered two mostly dry dekads in mid and late June, precipitation remained below normal in early or mid-July in northern Senegal, western and central Mali, most parts of Niger and in the Sahelian zone of Chad where substantial replantings have been necessary. However, rains increased significantly and progressed northwards during the last dekad of July, notably in southern Mauritania, western and central Mali and in southern and central Chad where they benefited recently planted crops. Widespread and abundant rains in July helped desalination of swamp rice in Guinea Bissau and crop emergence in The Gambia. In Cape Verde, rains have started on all islands, allowing first maize plantings. Overall, although growing conditions have improved since late July, crop prospects remain uncertain in several countries.
The last Meteosat satellite image up to the morning of 9 August (i.e about 4/5 of a full dekad) is indicating that rains decreased significantly over the Sahel, although cloud coverage remained widespread over the main producing areas, except in central and northern Mali and central and eastern Niger where no clouds were present (or only shortly). Therefore, some, but limited, rains are likely to have been received over most parts of Senegal, The Gambia, Guinea-Bissau, south-west and south-east of Mauritania, western and south-eastern Mali, northern Burkina Faso and western Niger. Rains have been more abundant over southern and central Burkina Faso and Chad. Following good precipitation in late July, soil moisture reserves have been generally reconstituted, but more rains are needed to avoid water stress, notably in Senegal, in western, central and northern Mali and in central and eastern Niger.
Desert Locust adults continued to appear during July in the summer breeding areas of the Sahel where there were several reports, many from nomads and locals, of swarms moving south in northern Mali and central Mauritania. In August, additional adults and perhaps a few swarms are likely to arrive from North-West Africa where control operations continued but some infestations have escaped detection and control, resulting in swarm formation and movement south towards the Sahel where breeding is expected to occur.
In these reports, reference will be made to four different eco-climatic zones based on the average annual precipitation and agricultural features, i.e. Sahelian zone, Sudano-Sahelian zone, Sudanian zone and Guinean zone. They are shown in the map and described below:
Sahelian zone: Where average annual precipitation ranges between 250 and 500 mm. This zone is at the limit of perennial vegetation. In parts where precipitation is less than 350 mm, only pastures and occasional short-cycle drought-resistant cereal crops are grown; all cropping in this zone is subject to high risk.
Sudano-Sahelian zone: Where average annual precipitation ranges from 500 to 900 mm. In those parts of this zone where precipitation is less than 700 mm, mostly crops with a short growing cycle of 90 days are generally cultivated predominantly sorghum and millet.
Sudanian zone: Where average annual precipitation ranges from 900 to 1 100 mm. In this zone, most cereal crops have a growing cycle of 120 days or more. Most cereals, notably maize, root and cash crops are grown in this zone.
Guinean zone: Where average annual precipitation exceeds 1 100 mm. Guinea-Bissau and a small area of southern Burkina Faso belong to this zone, more suited to root crop cultivation.
Reference will also be made to the Intertropical Convergence Zone (ITCZ), also known by its trace on the earth's surface, called the Intertropical Front. The ITCZ is a quasi-permanent zone between two air masses separating the northern and southern hemisphere trade winds. The ITCZ moves north and south of the equator and usually reaches its most northerly position in July. Its position defines the northern limits of possible precipitation in the Sahel; rain-bearing clouds are generally situated 150-200 km south of the Intertropical Front.
MAURITANIE NIGER SENEGAL