Report No 5- 10 October 1998
Report No 5- 10 October 1998
SUMMARYThe rainy season is nearing its end after abundant rainfall in September. Following decreased rains in late August, precipitation was generally widespread and above normal over most producing areas of the Sahel during the first dekad of September. Torrential rains were again registered in several areas of Niger where they caused flooding. Rains remained abundant during the second dekad, except in southern Mauritania, but they decreased significantly during the last dekad. Rains became abundant on southern islands of Cape Verde in mid to late September. Rainfall was particularly abundant in Guinea-Bissau. The latest Meteosat satellite image for the first few days of October indicates that cloud cover is clearly moving southwards, marking the end of the rainy season in most northern areas.
Reflecting good rainfall, crop prospects are generally favourable in Mali, Burkina Faso, Niger and in Chad except in the Sudanian zone affected by extensive flooding. In The Gambia and Senegal, crop prospects improved following regular rains since August but in northern Senegal additional rains are needed in October as the rainy season started late this year. In Mauritania, growing conditions were mostly favourable for rainfed crops in September. Crop prospects have improved in Cape Verde following increased rains in September. They are uncertain in Guinea-Bissau as the impact of civil disturbances on plantings and other agricultural activities is not clear. Joint FAO/CILSS Crop Assessment Missions are scheduled from mid-October to estimate with national services the 1998 cereal production. FAO's tentative assessment of yield forecast for cereals in the Sahelian countries is shown in Annex I.
Pastures are abundant. Grasshoppers are reported in most countries. Grain eating birds and insect attacks are also worrisome in several countries. Some limited Desert Locust activity is reported in Mali, Mauritania and Niger. A few additional adults may appear in northern Mauritania and persist in northern Mali and Niger.
SITUATION
BY COUNTRY
CAPE-VERDE
CHAD
GAMBIA
GUINEA-BISSAU
MAURITANIA
NIGER
SENEGAL
SOME
DEFINITIONSSahelian 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.
