COMITÉ PERMANENT INTER- ÉTATS DE LUTTE PERMANENT INTERSTATE COMMITTEE CONTRE LA SÉCHERESSE DANS LE SAHEL FOR DROUGHT CONTROL IN THE SAHEL

AGRHYMET MONTHLY BULLETIN N° M-05/05 July 2005

The overall good and rather well distributed rainfall in time and space, early sowing, good vegetative state of crops and relatively calm phytosanitary situation should not mask the July localized crop water stress, flooding and overflow of bodies of water in areas to be monitored during this cropping season.

„ The July 2005 monthly rainfall was poorly distributed in time. Admittedly, the fortnight of the month under review was characterized by abundant and well distributed rains. On the other hand, a break in rainfall, which ranged from a few days to two weeks, was observed during the second fortnight of July. As a result, the rainfall amounts recorded were below normal in many locations of the agricultural zone of the CILSS member countries. These localised rainfall deficits were observed in the Wilayas of Guidimaka and Hodh el Chargui, , the southern part of the area of Tambacounda, the Ziguinchor and Niaye areas, , Western Gambia, almost all over the agricultural zone of Guinea Bissau and respectively, southwestern and central , the area of Tillabéry and the southern part of that of Dosso, , and the prefectures1 of Guéra, Salamat, Ouaddaï, Middle Chari, Eastern and Western Logones, Chad (figures 1.1 and 1.2). Seasonal cumulative rainfall as at July 31st, 2005, was deficient in the coastal Niaye strip, Senegal, some places in the areas of Kayes, Sikasso and Ségou, Mali, Southwestern and Western Burkina Faso, here and there in the northeastern and southern parts of the areas of Tillabéry and Dosso respectively, Niger and the extreme South of Chad (figures 1.3 and 1.4).

„ With the start of the rainy season in earnest in July across the entire Sahel, characterized this year by relatively regular rains from June to July with rather significant cumulative rainfall, water levels rose in virtually all the perennial or ephemeral watercourses. The regularity of rains until mid-July across Central Sahel resulted in unusual streamflows in some temporary watercourses. The break in rainfall observed during the last dekad of July in the same area slowed down the rise in water levels. At the same period in Western Sahel, appreciable rains fell, which resulted in flooding in some places, particularly in The Gambia and Mali. These good rainfall conditions are responsible for a substantial rise in water levels in medium-sized reservoirs and even the overflows in some bodies of water.

With the expected intensification of rainfall in terms of significance and regularity in August over the entire Sahel, water levels will increase significantly across most basins with risks of overflow and flooding.

„ Favourable conditions for sowing under wet conditions were experienced early in much of the agricultural zone of the CILSS member countries where sowing was generalized well before mid-July 2005. This year, there were fewer sowing failures and resowing than before due to good rainfall distribution in space and time. On the whole, sowing dates were similar to average dates, except for some places of the Wilayas of Gorgol and Hodh el Chargui, Mauritania, the area of Kolda, the western and southern parts of those of Tambacounda and Matam respectively, Senegal, western and central Gambia, the areas of Cacheu and Oio, Guinea Bissau, the southern part of the area of Koulikoro and here and there in the areas of Ségou and Mopti, Mali, the area of Boucle du Mouhoun, Southwestern and Eastern, Burkina Faso, the two Logones and some places of the prefecture of Mayo Kebbi and

1 Administrative division

AGRHYMET Regional Centre P.O. Box 11011 NIAMEY (NIGER) TEL: (227) 73.31.16 / 73.24.36 FAX: (227) 73.24.35 Website: http://www.agrhymet.ne E-mail: [email protected] South Central Chad, where more than 10-day delays were observed. Early sowing of the same order were also observed in some places of Northern Senegal, southern Mauritania, the area of Mopti, Mali, northern Burkina Faso and the area of Zinder, Niger. This situation resulted in very heterogeneous phenological conditions, ranging from the seedling stage to the beginning of reproductive stage in the areas of the Sahelian domain and from the full vegetative growth stage to the reproductive stage in the areas of the Sudanese domain. Overall, crops conditions were adequate. Yet, as a result of the July poor rains, crops suffered from water stress in the Wilayas of Hodh el Chargui and locally in that of Guidimaka, Mauritania, the Niaye and Louga areas, Senegal, the northern part of the areas of Ségou and Mopti, Mali, Central Burkina Faso, the northern part of the area of Tillabéry, Niger and some places of the prefecture of Chari Baguirmi, Chad.

In these locations, soil water reserves were low during the period under review and crops will need substantial moisture in August in order to go through their reproductive stage (critical stage) under good conditions. Otherwise, decreases in yield could be observed in the above-mentioned areas.

„ The analysis of combined risk indicators (deficient rainfall, late sowing and crop water requirement satisfaction index) for all the CILSS member countries as at July 31st, 2005 enabled to produce a map of areas at risk to be monitored during this cropping season (figure 3.5). It pointed out that the area of Ségou, Mali, presented the highest risk since all the three indicators have been observed in some places of this area. Areas at moderate risk are those where two of these indicators were observed at any place in the area and areas at low risk are those where only one indicator was observed. The details of the indicators is indicated in the attached table I.

„ The phytosanitary situation remained relatively calm during the month under review. With the exception of Chad where desert infestations were believed to persist and were likely to develop, the other front-line countries (Mauritania, Mali and Niger) reported a situation calm since the beginning of the cropping season.

In the agricultural zone, the pressure of other pests also seemed to have been low.

With the improvement in ecological conditions, small-scale hatching of desert is likely in Mauritania, Mali and Niger. Significant development is possible in Chad, considering the ecological conditions, which prevailed during the month under review and the probable locust situation in Ouaddaï, Kanem and Batha.

Greater pressure of flower-feeding , and grain-eating birds is also expected during the coming weeks.

„ The break in rainfall, observed during the second dekad of July, had not significantly affected the gradual and normal growth of the vegetation across the Sahel. There was a significant northward advance of the vegetation front (figure 4.1) in the central part of the Sahelian area. The presence of the vegetation was observed beyond latitude 17° in the South of Mauritania and Central Niger. The vegetation front, which was very dense, progressed up to the Senegal River in the West, was beyond latitude 16° N in the South of Mauritania, stretched over much of the Southwest and the Niger River Inland Delta of Mali. It covered the entire agricultural zone of Chad and the Lake Chad area.

CAPE VERDE

Preparation of farms, putting inputs in place and dry sowing of maize continued in many places of the archipelago. Sowing of maize and beans under wet conditions must have started across the humid strata of the Southern islands, particularly Santiago and Fogo.

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AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 2 MAURITANIA

Sowing intensified during the first fortnight of July in much of the agricultural zone, except for the Wilaya of Hodh El Garbi where sowing had already started in late June. Sowing dates were a bit late in the Wilaya of Guidimaka and Hodh El Chargui, early in that of Hodh El Garbi and equivalent to the average elsewhere in the country’s agricultural zone. Overall, as at July 31st, 2005, crop water requirements were satisfied, except locally for the Wilayas of Guidimaka and Hodh El Chargui where crops suffered from moisture deficit, particularly during the last dekad of July.

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No manifestation of desert locusts was reported during the month under review.

Although no was reported over the period under review, one should remain alert because ecological conditions favourable for its breeding prevail in the Southeast and Central part of the country.

SENEGAL

With the start of the rainy season in earnest in Senegal, streamflows in all the ephemeral watercourses were sometimes significant in July. At Kidira, a very significant flood wave was recorded in the Falémé during the month under review. At Kolda, the first streamflows were observed in the Casamance River, as of July 8th, 2005.

At Bakel, the Senegal River discharges, subjected to regulation by the Manantali dam, were on the rise during the first two dekads of the month under review before decreasing slightly over the last dekad. With the start of flow in the basin’s non-regulated tributaries, the change in water levels in the valley will depend on the instructions governing of the Manantali dam management to meet the various needs and the natural water inflows from these tributaries.

If the good rainfall conditions experienced so far continue across the basin, good streamflow conditions are expected in the Senegal River basin in August and September as already indicated by the update of seasonal hydrological and climatic forecasts. As a result, there are non-negligible risks of flooding across the valley considering the water inflows expected from non-regulated tributaries.

The rainy season started in earnest at the beginning of the month under review in the areas of Thiès, Louga, Saint Louis and the northern part of those of Matam, Fatick and Kaolack, a bit early, locally, in the areas of Diourbel, Louga and Saint Louis. As at July 31st, 2005, some locations of the northern part of the area of Louis Saint had not received any measurable rain for sowing yet. Overall, Crop water requirements were satisfied countrywide, except for the western part of the areas of Louis Saint and Louga where significant moisture deficits were observed.

No report of desert locusts was received.

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 3 The first series of hatching of Senegalese grasshoppers (Oedaleus senegalensis) were observed during the second week of the month under review on millet seedlings in the plots of Khelcom whilst in the department2 of Kolda an infestation of variegated locusts persisted (Zonocerus variegatus). The populations decrease after treatment.

Flower-feeding insects appeared in the area of NGanda during the first week of the month under review, but fortunately, crops were at the seedling stage. The most severe infestations were observed during the last week of July in the department of Nioro.

During the same period, defoliating caterpillars belonging to various species, particularly the Hairy caterpillar (Amsacta moloneyi and Metacathacsus minutus) were observed in the area of Nganda on cowpea and groundnut seedlings. Hairy caterpillars started to appear during the second week in the departments of Louga and Kébémer where they caused resowing in the wake of their attacks. These infestations affected the department of Dagana and the area of Dakar during the last week of July. In addition, army worms Spodoptera exempta were at the root of damage, which were sometimes severe on seedlings in the departments of Nioro and Ziguinchor. Other defoliating caterpillars were observed on maize and sorghum seedlings in the department of Kolda. This infestation affected the departments of Sédhiou and Bignona during the third week of the month under review.

During the coming weeks, an increase in the numbers of grasshoppers and flower-feeding insects is expected as a result of the significant improvement in ecological conditions. In the same way, manifestations of grain-eating birds will be increasingly frequent.

THE GAMBIA

The rainy season started in earnest during the last fortnight of June with a slight delay in the Upper River division however. Overall, crops have been experiencing good moisture conditions since the onset of the season.

GUINEA-BISSAU

The areas of Gabu, Bafata, and Oio were late in recording the measurable rains for sowing received almost countrywide since June. Overall, crops have been experiencing good moisture conditions since the onset of the rainy season.

MALI

The month of July was characterized by continued rise in water levels in all the watercourses of the country. At Koulikoro, the Niger River water levels rose very significantly as of mid June and continued to increase during the month of July. Discharges were much higher than last year. The trend of water levels was similar to 2003.

2 Administrative division AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 4 Niger at Koulikoro 2000 Aver. 2002 2003 Dis 1500 2004 ch 2005 arg e 1000 (m 3/s ) 500

0 05-Jan 24-Feb 15-Apr 04-June 24-Jul 12-Sept Date

Figure 1.1: The Niger River discharges as at July 31st, 2005 at Koulikoro

If the good rainfall conditions recorded in late July extend into August and September as predicted by the update of seasonal hydrological and climatic forecasts, during the coming months appreciable streamflows should be expected in the Senegal River basin and in the upper reaches of the Niger River. It is important to point out that there is a non-negligible risk of flooding.

The onset of the rainy season continued during the month under review in the northern part of the areas of Kayes, Koulikoro, Ségou and Mopti. More than 20-day delays were experienced in the northern part of the area of Sikasso, the central and eastern parts of that of Ségou and the southern part of the area of Mopti. So far, crops have been experiencing adequate moisture conditions, except for the northern part of the areas of Ségou and Mopti where deficient conditions were observed.

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During the first dekad of the month under review, some mature solitary adult desert locusts were present in Tamesna and central Adrar des Iforas.

With the improvement in ecological conditions, small-scale breeding can occur in the coming weeks in the breeding areas of this pest.

BURKINA FASO

Sowing was performed countrywide before the beginning of July. The Central and Eastern parts of the country were late in sowing, particularly in the areas of Hauts Bassins and Boucle du Mouhoun. Sowing was performed in advance in the Sahelian domain. Overall, crops have been experiencing good moisture conditions since the onset of the rainy season, with some pockets of drought observed towards the end of the month under review in the central areas of the country (Central Plateau, North and North Central) and the Boucle du Mouhoun however.

NIGER

In Niamey, July was characterized by an unusual rise in the Niger River water levels with maximum flood recorded in the middle of the month under review. This situation was due to the significant and regular rains received across the sub-watersheds of the Niger River located on the right bank in Burkina Faso. In Niamey, the Niger River discharge increased 260 m3/s to 1110 m3 /s from July 1st to 15th, 2005, decreased subsequently and rose again at the end of the month under review. The mean monthly discharge for

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 5 July was 674 m3/s against 451 m3/s last year, that is, an increase by a little less than 50%. This monthly discharge was about ten times higher than the mean monthly discharge for July, which is 76 m 3/s. At the end of July and in early August, discharges were very similar to those of 2003 when a significant local flood was observed in Niamey in September.

With the return and intensification of rains in August and as indicated by the update of seasonal climatic and hydrological forecasts, as in 2003 and 1998, significant local floods are expected in Niamey with high risks of floods in the River valley.

Moy Niger à Niamey 2500 2002 2003 2000 2004 2005

1500

1000 Débit (m3/s) Débit

500

0 05-janv 24-févr 15-avr 04-juin 24-juil 12-sept 01-nov 21-déc Date

Figure 1.2: The Niger River Discharges as at July 31st, 2005 in Niamey

Sowing was expanded to the Sahelian domain during the first fortnight of July, except for the northern part of the area of Tillabéry (department of Ouallam) where it had not been performed yet in some places on July 31st, 2005. Elsewhere, the onset of the rainy season occurred under normal conditions and even early in some places of the areas of Tillabéry and Zinder. Overall, moisture conditions were adequate for crop development, except for the department of Tillabéry where cases of wilting were observed during the last dekad of the month under review (departments of Téra, Tillabéry, Ouallam, Flingué and Kollo).

Adult, solitary desert locust breeding occurred in the second dekad in the department of Tanout (area of Zinder) and isolated locusts were present in the pastoral zone in the first and third dekads.

In the agricultural zone, Senegalese grasshoppers bred in the first dekad of the month under review in the departments of Mayahi, Aguié and Madarounfa (area of Maradi) and Tanout (area of Zinder). Hatching continued during the following dekads and affected the departments of Tera, Ouallam and Tillabéri (area of Tillabéri). Hatching of rice grasshopper ( daganensis) occurred during the third dekad in the department of Keita (area of Tahoua). In the same way, variegated locusts were present on maize and cassava in the department of Diffa during the last two dekads of July.

Overall, small numbers of grasshoppers were present in the above-mentioned departments.

The first infestations of flower-feeding insects were observed during the first dekad of July on millet at the heading/flowering stage in the departments of Gaya (area of Dosso), Gouré (area of Zinder) and Maïné Soroa (area of Diffa). These infestations affected the departments of Tessaoua (area of Maradi), Keita (area of Tahoua) and Mirriah (area of Zinder) in the second dekad of the month under review and the department of Kollo (area of Tillabéry) in third dekad of the said month. The pressure exerted by these insects increased during the third dekad, particularly in the areas of Dosso, Maradi and Tillabéry.

The month under review was also characterized by localised attacks of leaf beetles on millet in the areas of Diffa, Dosso, Maradi and Zinder.

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 6 The first attacks of hairy caterpillars on millet were reported in the departments of Diffa and Maïné Soroa (area of Diffa) during the second and third dekads of July and on cowpea in the area of Zinder (Commune3 of Toumnia) during the third dekad of the said month.

Small-scale breeding of desert locusts is likely in the pastoral zone. During the coming weeks, an increase in the numbers of grasshoppers and flower-feeding insects is also expected in the agricultural zone. Likewise, bird attacks will be increasingly frequent.

The NDVI map (figure 4.1) and profiles (figure 4.3.a and 4.3.b) indicate a pocket of poor vegetative cover in Niger (northern Tillabéry and west central Tahoua). The curves over the various longitudes on the map show that the 2005 growing season’s phytomass was below average. This situation is confirmed by some rainfall data (figure 4.4).

Considering the situation of food insecurity affecting the area, the latter must be closely monitored until the end of the cropping season. Improved rainfall conditions in August and September could result in good crop and pasture development.

This ecological situation augured well for favourable conditions for fodder development in the pastoral zone across the Sahel. Herbaceous and woody biomass is expected enable herds to continue their transhumance without great difficulties.

CHAD

The northern areas of the prefectures of Chari Baguirmi and Ouaddaï, the Lake prefecture, the southern part of those of Kanem, Batha and Biltine performed their first series of sowing during first fortnight of July. Overall, the onset of the rainy season occurred late about everywhere, particularly in the prefectures of Tandjilé, the two Logones, Mayo Kebbi and the southern part of Chari Baguirmi. As at July 31st, 2005, crops experienced good moisture conditions countrywide.

Although no information was received from this country during the month under review, residual infestations of desert locusts were believed to be underway in the areas where hatching occurred in June. These include Ouaddaï, Kanem and possibly Batha.

Likewise, the agricultural zone could be faced with other pest attacks: grasshoppers, flower-feeding insects and diseases.

Considering the good ecological conditions, which prevailed in the agricultural zone and the areas where desert locust hatching occurred, significant pest development could occur.

3 Administrative division AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 7

Figure 2.1: The July 2005 Satellite-Based Cumulative Rainfall Estimates for the CILSS Member Countries

Figure 2.2: Comparison of the July 2005 Satellite-Based Cumulative Rainfall Estimates to the Past 19 Years’ Average

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 8

Figure 2.3: Satellite-Based Seasonal Cumulative Rainfall Estimates as at July 31st, 2005 for the CILSS Member Countries

Figure 2.4: Comparison of the Satellite-Based Seasonal Cumulative Rainfall Estimates as at July 31st, 2005 to the Past 19 Years’ Average

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 9

Figure 3.1: The 2005 Successful Sowing Dates in the CILSS Member Countries

Figure 3.2: Comparison of the 2005 Successful Sowing Dates to the 1971-2000 Average for the CILSS Member Countries

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 10

Figure 3.3: Crop Water Requirement Satisfaction as at July 31st, 2005 in the CILSS Member Countries

Figure 3.4: Soil Water Reserves as at July 31st, 2005 in the CILSS Member Countries

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 11

Figure 3.5: Risk Levels as at July 31st, 2005 in the CILSS Member Countries

Figure 4.1: Performance of the Vegetation as at July 31st, 2005

AGRHYMET MONTHLY BULLETIN – July 2005, Volume 15, N° M-05 12

rd Figure 4.2.a: NDVI for the 3 dekad of July 2005 – Area Figure 4.2.b: red squares: location of rainfall stations with with a poor index. available illustrative data

1 1.5 2 2.5 3 3.5 4 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 4.5 5 5.5

0.25 0.25

0.2 0.2

0.15 0.15 NDVI 0.1 NDVI 0.1

0.05 0.05

0 0 may1 may2 may3 jun1 jun2 jun3 jul1 jul2 jul3 may1 may2 may3 jun1 jun2 jun3 jul1 jul2 jul3 Dekad Dekad

Figure 4.3.a: The 2005 NDVI at 15º N for Various Figure 4.3.b: Average NDVI at 15º N for Various Longitudes Longitudes

Bankilare Ouallam Banibangou Sanam Toukounouss

90 75 60

45 30

15 0 may1 may2 may3 jun1 jun2 jun3 jul1 jul2 jul3 Dekad

Figure 4.4: Rainfall (mm) over some Locations of the Northern Part of the Area of Tillabéri

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Table I: Indicators for Identifying Areas at risk as at July 31st, 2005.

Country / Rainfall Anomalies Late sowing Water Requirement Indicator Satisfaction BF Seasonal rainfall anomalies: Pockets of late sowing in the Poor reserves almost all over areas of Boucle du Mouhoun, the country and poor WRSI Deficient Southwest and West the Southwest and East (Water Requirement Satisfaction Index) in the July rainfall anomalies: Areas that performed resowing Central part Deficient Southwest and Central part in the Boucle du Mouhoun (very deficient Southwest locally) CD Seasonal rainfall anomalies: Sowing failures and very late Poor WRSI locally in Chari Deficient extreme South resowing in much of the two Baguirmi Logones and here and there in July rainfall anomalies: Mayo Kebbi. Localized late Deficit in Guéra, Salamat, Ouaddaï, sowing in the South Central part Middle Chari, Eastern and Western Logones GB Deficient Late sowing here and there in Cacheu and Oio GM Deficient Western area Late sowing in some places in the West and Central Parts Ml Seasonal rainfall anomalies: Late sowing: Poor WRSI in the northern The southern part of Koulikoro parts of Ségou and Mopti Local deficit in the areas of Kayes, and locally in the areas of respectively Sikasso and Ségou Ségou and Mopti

July rainfall anomalies: Almost the entire agricultural zone of the country experienced a deficit MR. July rainfall anomalies: Sowing failures and resowing in Poor WRSI in Hodh el Local deficit in the Wilayas of areas that performed early Chargui and locally in Guidimaka and Hodh el Chargui sowing in Gorgol and Hodh el Guidimaka Chargui NG Seasonal rainfall anomalies: Very poor or poor WRSI in Local deficit in the northeastern part Northern part of the area of of the area of Tillabery and the Tillabery southern part of the area of Dosso

July rainfall anomalies Deficit in the area of Tillabery and the southern part of that of Dosso SN Seasonal rainfall anomalies: Late sowing in the areas of Poor WRSI in the Niaye area Deficient coastal strip Kolda, western and southern parts of those Tambacounda July rainfall anomalies: and Matam Deficit in the southern part of the area of Tambacounda, the Ziguinchor and Niaye areas

AGRHYMET Regional Centre The analyses contained in this bulletin are based on the July 2005 P.O. Box 11011 NIAMEY (NIGER) information. This document is also posted on the AGRHYMET’s Tel: (227) 733116 / 732436 Website: Fax: (227 732435 http://www.agrhymet.ne. E-mail: [email protected]

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