fleuve niger carte
In the inland delta, for instance, the flooded area spans 7,000 to 20,000 km, many days the water level stays above the 4.50-m mark in Mopti), Village fish farming still has considerable potential, but in other areas (outside the large-scale commercial fishing areas) and with other population groups (more farming-oriented populations, especially) (Niaré. Fish production (in tonnes a year) dropped considerably during the long drought (1973-1993) but rose again once the average or good swells returned. It applies to all the water under the hydraulic domain, i.e. Sur les anciennes cartes européennes, le nom est donné au bras moyen du fleuve au Mali actuel. Table 7 shows that usable farmland can indeed vary considerably from one year to the next. Wildlife elsewhere in Niger River’s valley in Mali is less exciting: it is akin to that in the neighbouring Sudan-Sahel (barring the fish, of course). Malgré sa faible anthropisation, le fleuve Niger fait partie de ces fleuves (tout comme le Sénégal) qui ont été fortement aménagés depuis les années 1980 à cause de l'accentuation de la sécheresse. A number of weather-related and anthropogenic factors over the last century have taken a toll on biodiversity in these riverside ecosystems. The dry season there lasts 6 to 9 months. Between Ké-Massina and Lake Debo, this inland delta comprises a series of potholes and plains that flood every year (provided the swell is substantial enough). The water in this surface table, in other words, is unsuitable for human consumption by WHO standards. 15We usually cut this area into four zones to characterise this climatic gradient, as follows: Conditions d’utilisation : http://www.openedition.org/6540. Suetonius rapporte que les Romains se sont rendus au "Ger", bien qu'en rapportant le nom de toute rivière dérivé d'une langue berbère , dans laquelle "gher" signifie "cours d'eau", la confusion pourrait facilement surgir. Pump-assisted irrigation started developing here in the early 1980s, when rainfall and swells started dwindling. A small portion of Mali’s fish production comes from the Senegal river basin (from the Manantali dam lake). Generally speaking, however, it is fair to say that Comanav’s two ships and the many smacks using this river do not release substantial amounts of pollution. The deeper formations (the ones growing under 280 cm to 400 cm of water) could disappear altogether and be replaced by varieties growing in shallower water. Lastly, water birds are part of the delta’s appeal – and what make this and the Dogon area Mali’s leading tourist destination. Four 11.9-MW Kaplan turbines in the power station generate electricity. The scant tropical rain falls between June and September. Là, séparant l'Afrique de l'Éthiopie, les rives en sont peuplées, sinon d'hommes, du moins de bêtes et de monstres : créant des forêts dans son cours, il traverse par le milieu l'Éthiopie, sous le nom d'Astapus, mot qui, dans la langue de ces peuples, signifie une eau sortant des ténèbres. See Niamey photos and images from satellite below, explore the aerial photographs of Niamey in Niger. En 1570, sur cette carte hollandaise, le Niger est lié au Sénégal. Healthier flooding after 1994, paired with efficient protection measures (Dentaka and Akkagoun forests) may have reversed this trend. It is headquartered in Niamey and aims to promote member States’ cooperation and to integrate power-generating, hydraulic, farming, livestock-farming, fishing, fish-farming, forestry, logging, transport, communication and industrial operations across this basin. The latter would keep the delta flooded for longer. The last thirty years have seen dwindling flow rates compounded with human activities put growing pressure on the natural environment and hitting large wildlife species. The Timbuktu region, for instance, counts less than 1 inhabitant per km2. 109The district of Bamako’s factories produce 9,715 metric tonnes of waste a year. Bamako’s surface water table is completely polluted: it is very near the surface, hence near the many individual sources of pollution in that district. Au retour, il publie Niger et Bénué en 1880[6]. 169However, these different structural changes are not, at least for the time being, affecting this resource’s yield (i.e. Lastly, associations have grown into prominent roles since the 19911992 regime change. Mali (inset), the Niger River and the inland delta (oval). According to this same study, Mali’s urban population should continue to increase at 4.5% a year to 9.15 million people in 2025 (up from 3.2 million in 2002). It is also altering flow patterns and increasing the risk of flash flooding. Outside bad-weather years (such as 2004), Mali can typically cover more than 100% of its food requirements. There, the high concentration of colon-type bacillus and faecal streptococcus make the surface water unsuitable for drinking by WHO standards. Le dragage vise à faciliter le transport des marchandises vers des colonies isolées situées au plus profond de l' océan Atlantique . Les caravanes sahéliennes qui commerçaient avec l'Afrique du Nord depuis Tombouctou rapportaient que cette ville était irriguée par un grand fleuve mais c'était la seule information dont disposaient les géographes européens qui ont, de manière plus ou moins sérieuse, plus ou moins documentée, rempli les blancs. 61We can look at this system in terms of “usable farmland” (how much land has enough water for rice to grow properly). If the question is whether some of the species caught 30 or even 60 years ago have grown rarer or disappeared, however, we can. Manantali, a new dam that was starting up in the Senegal River basin at that time, provided backup. Figures are relatively stable in the large traditional cattle-breeding area in the north of the country (Mopti), and growing in the south. Comme le Nil, le Niger est inondé chaque année; cela commence en septembre, culmine en novembre et se termine en mai. The rainfall, landscape, basin lithology and resulting soil quality explain the bulk of the Niger River’s erosion rates. On dit qu'il coule au sud de (« sous ») l'Éthiopie (« l'Afrique ») et se jette dans le lac du Nil. Evapotranspiration (over 1,700 mm a year south of Sikasso and more than 2,500 mm a year in Tessalit) runs in the opposite direction. The district of Bamako’s factories produce 9,715 metric tonnes of waste a year. Il prend sa source au pied des monts Tingi, à la frontière de la Sierra Leone et de la Guinée. (Ministry of Mines and Water) is the main authority governing the Niger River in Mali. Consumption of domestically-produced food in cities is expected to rise 3.5 times faster than that in rural environments over the period from 1995 to 2025. Alexander Gordon Laing, militaire britannique en poste au Sierra Leone, est le premier explorateur qui, au début des années 1820 estime avec précision les coordonnées géographiques de la source du fleuve (quand bien même il ne peut l'atteindre, la région étant aux mains des indigènes). Alors que les espèces végétales déclinaient fortement, les humains ont migré vers la région fertile de la courbe du fleuve Niger, avec des ressources abondantes, notamment des plantes pour le pâturage et des poissons. Certains le confondaient avec le Sénégal ou avec le Congo, d'autres en faisaient une branche du Nil et pour d'autres encore, c'était une rivière tributaire d'un lac intérieur. Bien que le delta du Niger semble être un candidat évident, c'était un labyrinthe de ruisseaux et de marécages qui ne ressemblait pas à la tête d'un grand fleuve. So scientists only agree on the fact that temperatures will rise and that rainfall is unpredictable. In Mali, cotton is a rain-fed crop. The DNH gathers the bulk of the hydraulic information and stores it in Hydrom, a database that is currently being upgraded (Hydraccess). This comes as no surprise (this dam is a spillway and fairly small). It is situated between parallels 13 and 17 north and meridians 2°30 and 6°30 west. Table 10 – Water requirements for fish and fishing. Malgré sa navigabilité et sa situation centrale au Mali et au Nigeria, il ne constitue pas l'axe majeur espéré. They are in charge of herd trails and may regulate access to resources and charge herders for using them. Or, otherwise put, the occasional poor flood will not affect them. 6.99% a year on average (fig. There appears to be – certainly since the late 19, Surface conditions seem to amplify the climate fluctuations outlined above, adding a form of inertia to existing rainfall patterns (, Colonial records dating back to the early 19. After Lake Debo, naturally-occurring dunes haphazardly feed water through a vast web of thoroughfares and into a number of lakes. Le résultat est une région de ruisseaux tressés , de marais et de lacs de la taille de la Belgique ; les crues saisonnières rendent le delta extrêmement productif pour la pêche et l' agriculture . The NBA stays abreast of country-specific development plans. 165The information below, therefore, only includes the species that fishers catch (or caught). Some people fish sporadically, but are primarily farmers. Table 17 (p. 234 to p. 239) shows the systems used to gather and monitor information about the Niger River. This is altering the river’s ecosystems: river plants have disappeared taking spawning beds with them. The term “trend”, as an aside, warrants a word of caution: what may look like a trend over a given period of time may, in fact, be part of a longer cycle. In volume terms, cichlids (tilapia, broadly speaking) predominate in fishers’ nets (alongside Clarias and Labeo). Territorial communities take part in the meetings of basin committees and councils founded by the new. The Middle Niger lost its central role on trans-Saharan trade routes, but nonetheless continued to serve as a hub for regional salt, rice, fish and livestock commerce. D’Amato and Lebel (1998) go a step further linking this to a decline in the frequency of cyclone passages during those two mid-season months. When the impoundment lake is full (i.e. They protect plantations by eating locusts, grasshoppers and other insects, and thereby balance the delta’s ecosystem and bolster its production. the dry grasslands growing on the delta’s outskirts and unwatered mounds could cover three times as much surface (more than 900,000 ha); deep-water grass (in 150 cm to 400 cm deep water) would shrink considerably. Their sizes differ considerably. This has since changed: Mali is not exporting power from a balance-of-trade angle, but nonetheless supplying Senegal and Mauritania from Manantali. are relatively unaffected by poor swelling. Monitoring and servicing heavy-duty hydraulic equipment is one issue. Une caméra a été utilisée pour illustrer le livre ultérieur de Jean Rouch "Le Niger en pirogue" (Fernand Nathan, 1954), ainsi que "Descente du Niger" de Jean Sauvy (L'Harmattan 2001). The bulk of the Niger River basin’s production, in turn, is fairly concentrated: about 80% of it (40,000 to 120,000 t a year) comes from the Niger River’s inland delta (broadly, from Ké-Massina to Diré, encompassing the lakes). It most probably generates very little pollution at this point (only the hydrocarbon released by the engines of vessels carrying migrating fishers or fish). 120Fractured aquifers are associated with crystalline deposits (the base) or Precambrian and Palaeozoic sedimentary deposits. They scatter the seeds, rainfall triggers the growth process, and then the floods take over. 25It is an earth dam. Several studies (Alpha et al., 1991; Iwaco, 1996; Palangié, 1998) have characterised the pollution and found a high concentration of nitrates, nitrites, phosphates and chlorides, possibly from a variety of sources (detergents, fertilisers or decomposing organic matter). its ability to produce as much biomass as it loses in a year). They return in November or December, depending on how fast the water recedes. Restait à en trouver la source. 122However, as regards this last aspect, weekly monitoring of the quality of well and drilling waters and of surface water in the cotton-growing area (CMDT in south Mali) showed isolated but noteworthy pesticide-pollution spikes (DDT, especially), associated with fertiliser storage issues or unsuitable use (Bonnefoy, 1998). D’Amato and Lebel (1998) go a step further linking this to a decline in the frequency of cyclone passages during those two mid-season months. Intensive farming is gaining ground in the cotton plantations on the Niger River’s basin, so pollution from chemical fertilisers and pesticides is likely to follow and intensify. Marseille : IRD Éditions, 2007. They can be referred to as occasional fishers and come from a wide variety of ethnic backgrounds. Niger. The water may also contain pesticides, and certainly contains very high amounts of bacterial pollution (colon-type bacillus and faecal streptococcus, total germs) from diffusing wells that are either too deep or too small, from pervious pit toilets, or from faecal matter carried by surface water through wells (which generally lack proper rims). Much of the Sudan-Sahel climate’s variability is due to these patterns (low-frequency fluctuation). Introduction. In fact, the loss of sediment across the delta is practically directly proportional to the suspended matter that enters it. 80Higher efficiency, however, is one of the key issues in efforts to develop these schemes and to improve overall river-water management. These canals feed 77,200 ha of Office du Niger full-water-control land growing rice and market produce, 3,000 ha of controlled-submersion Office Riz Ségou land growing rice and 5 000 ha growing sugar cane in the Sukala agro-industrial area. » Notons qu'en dépit de ces explications, le Girin et le Nil ne sont pas, topographiquement parlant, reliés par le cartographe antique. This swell crests in September in Bamako, in October or early November in Mopti, in December in Kabara (Timbuktu) and in late January in Gao. Woody vegetation, it seems, has been shrivelling a fairly limited 0.05% a year over the past fifteen years (87 km. 185However, despite these developments, the basic ecological mechanisms underlying this river’s productivity and its ecosystems (in terms of their ability to generate adequate biomass quality unaided) are intact. MARIE, Jérome (dir.) So the annual cold-season floods in Gao (January-February) would probably dwindle and disappear. Pour la pièce, voir, Carte du bassin du Niger et plan d'investissement, Le droit international et le fleuve Niger, Della descrittione dell'Africa et delle cose notabili che ivi sono, la gestion intégrée des ressources en eau, Informations et carte du bassin versant du Niger, Carte du bassin du fleuve Niger sur l'eAtlas des ressources en eau, Les courants du Niger: explorer la vie et la technologie le long du fleuve Niger, Bibliographie sur les ressources en eau et le droit international, https://openaccess.leidenuniv.nl/handle/1887/ 13541 (2005), licence Creative Commons Attribution-ShareAlike, Creative Commons Attribution-ShareAlike 3.0 Unported License. The rural population should shrink from 73% today to only 51% of the total (i.e. 214Lastly, associations have grown into prominent roles since the 19911992 regime change. Increase in Mali’s power generation. Sa source et son delta ne sont pas indiqués. Maximum high-water flow rates in Ké-Massina (downstream from Markala, at the entrance of the delta) are in a 3,000 to 5,000 m. /s change would be tantamount to a substantial 10% to 18% of the flow. But demand is growing fast and capacity could fall behind in a few years’ time – as early as 2007, some say (cf. L'explication la plus probable est que les Portugais, comme ils le font pour le Sénégal, adoptent le nom local du fleuve et l'étymologie la plus probable, si l'on retient cette hypothèse, est le touareg gher n gheren (« fleuve des fleuves ») abrégé en ngher et en usage le long des rives à Tombouctou[1]. ILCA scientists found 189 species (137 herbaceous species and 52 woody ones) in the delta. This 1975 agreement defines and organises the natural area preservation terms. Some risk factors, however, are intensifying. Bamako should see the sharpest surge (its population should double). When it is built, this dam will most probably be used to generate electricity (like Selingue). “Village Irrigation Areas”, often backed by NGO-sponsored “projects”. The early 20th century brought another very dry period. Water hyacinths are something of a hazard and can indeed cause serious concern in specific spots (dam intakes, mainly). The sharp low-water stage then continues until May, June or July. The developments we have discussed, however, do have negative consequences: Lastly, it is important to remember that healthy fish yields hinge on healthy river and plain ecosystems and, in particular, on generous annual flooding in the plains. Opening up tunnels to the surface will not only open the door to the pollution lying there (if suitable measures to protect the system are not implemented). Table 14 summarises this. Neither the Niger River in general nor the delta in particular can any longer be considered as large wild, unspoilt areas. First of all, it is not easy to tell what exactly defines a fisher, and secondly statistical coverage is inadequate. This code, in turn, lays the foundations for new water-management regulation and endorses the agencies in charge of administrating water resources. The best pastures, the. 48Fomi, lastly, is in the upper basin in Guinea. 151Based on Pirl research (1988), the Domestic Energy Strategy (or SED for Stratégie énergie domestique) recalculated the annual production of areas covered by the delta’s various forest stands (table 15). Sur les anciennes cartes européennes, le nom est donné au bras moyen du fleuve au Mali actuel. Envoyer l'article. ». Floating-rice varieties derived from. It spanned about 160,000 ha in the late 1980s (according to the 1988 PIRL project report), and probably spans between 180,000 and 200,000 ha today. It is not deep enough during the low-water season. L'aménagement de barrages (le barrage hydroélectrique de Sélingué, celui de Kainji) a désormais la vocation de sortir les pays africains de la dépendance énergétique (hydroélectricité) et céréalière (irrigation de périmètre de riziculture). As fishing is intensive, catch sizes decrease as the campaigns move on. Its wealth came from gold, salt and slave trading, and its eminence crested between 1450 and 1650, during the Gao Empire’s apogee. Arguably, land-development laws and authority malfunction before 1991 – which replaced the handed-down land-administration rules that local breeder, fisher and farmer communities had applied thereunto – explain a lot of this destruction (Marie, 1989; Moorehead, 1997). More than half the wells cut into these aquifers can provide over 10 m3/h, and some of them can produce more than 50 m3/h. (Eds.) When it reaches full capacity, Manantali will be generating 0.41 TWh (at least for Mali; the rest of will go to Senegal and Mauritania). Traditional sources of energy (wood and charcoal, basically) are still predominant (accounting for about 90% of the total). We will be following this approach, dissecting the Sudan-Sahel climate’s several components and showing which ones intertwine into what its people can perceive as a “trend” on a ten-year basis. These schemes are generally small, and run by private concerns or village communities, i.e. Some people and households live exclusively from fishing, and often migrate to wherever fish is most abundant. 32The channels emerging left of the pond comprise the feeder channel (designed to carry 200 m3/s) which splits into the Sahel canal, Massina canal and Costes-Ongoïba canal. Different thicket varieties are part of the landscape as well. « Le Nigris a la même nature que le Nil ; il produit le roseau, le papyrus et les mêmes animaux ; la crue s'en fait aux mêmes époques; il a sa source entre les Éthiopiens Taréléens et les Oecaliques. Au fil du temps, l'érosion en amont par le Niger inférieur a entraîné la capture des cours d'eau du Niger supérieur par le Niger inférieur. As a point of comparison, there were 1.75 million inhabitants (i.e. Improving yields, it follows, is the key. This estimate may be rough, but it nevertheless points to the fact that fishing plays an important role even if it only contributed a scant 4.2% of Mali’s GDP in 1995 (Breuil et al., 1996). 88It is not easy to tell how many fishers there are in Mali for two reasons. Power production and consumption are evolving pretty much in tandem, making Mali practically self-sufficient in electric power. Five-, three- or two-yearly fluctuations only account for 15% to 20% of the total variability. 113These boats produce a mixture of hardly-quantifiable forms of pollution. These systems follow: river-fed and rain-fed systems are specific to the river valley and, especially, to the inland delta; full water control (the only ones that can be described as irrigated). These forests span 5,000 ha and play a critical role in water-bird reproduction; Acacia nilotica and Acacia seyal forests, mainly watered by percolation, but sometimes secondarily watered by swells (water levels do not exceed 0.6 m). Territorial communities administrate grassland resources in their area. The impoundment lake will probably hold 6 billion m. According to a 2004 IEPF study, annual production in 2002-2003 stood at 0.46 terawatt-hour. The, Note * Annual average based on observation over a two-year period Source: Wimenga et al., 2002, The presence of large water-bird colonies seems linked to the integrity of flooded. The size of the tillable area, here, is linked to the area covered by the flood, and therefore linked to swell levels. Carte du bassin du Niger. They have continuous or semi-continuous tables, depending on the density of the fracture networks in them. There are other wetlands in the Sudan-Sahel area, including the Senegal delta (Djoudj), the Hadjia-Nguru floodplain in Nigeria, the Logon River’s, Chari River’s and Lake Chad’s floodplains, and the Sudd swamp in Sudan. Territorial communities can, in particular, build and run rural or city water-management facilities, organise rural endeavours and agro-sylvo-pastoral production. Upstream, water would spill over the left and right banks in two places, flooding a total of 150 km. « ce fleuve est nommé Grin, d'autres l'appellent Nil. 41This dam is expected to reshape the annual swelling from the rainy season higher up the basin. Appropriate community organisations work with professional organisations and technical agencies to regulate these endeavours, and set the levies for accessing pastures after consulting the Chambre régionale d’agriculture. It has kept a remarkably homogeneous fauna, due to exchanges with other basins. Some of the surface water, especially in the north and northeast of the Niger River’s inland delta, is in lakes that only fill when swells rise beyond certain thresholds. On dit qu'il coule au sud de (« sous ») l'Éthiopie (« l'Afrique ») et se jette dans le lac du Nil. The first such codes date back to the early days of independence (and replaced traditional systems). Large ships can only use it from early or mid August through mid December or early January, depending on how long the high-water stage lasts and how much water it brings (both of which generally vary in synch). It neither imported nor exported electricity until 2002. 56Rice has become more prominent for two reasons: because rice-farming areas has been growing regularly since the early 1980s, and because average yields have grown concomitantly (from 1 t to 2 t/ha). The catch one year has never been seen to hamper the catch the next. Au retour, il publie Niger et Bénué en 1880[6]. » Hélas pour les géographes futurs, Pline ne nous renseigne pas sur ces deux peuples. Association pour la promotion et la découverte des parties intérieures de l'Afrique, L'eau et le droit international : bibliographie sélective, Liste de fleuves dans le monde classés par continents, Afrique : Pays du Bassin du Niger (2006) : Établissement d’un Programme d’Investissement et Mise en place des Investissements, Agropolis, Gestion intégrée des ressources en eau dans les bassins du Limpopo, du Mékong et du Niger (projet ECHEL-Eau 2005-2010), https://fr.wikipedia.org/w/index.php?title=Niger_(fleuve)&oldid=175978720, Catégorie Commons avec lien local identique sur Wikidata, Article de Wikipédia avec notice d'autorité, Portail:Lacs et cours d'eau/Articles liés, licence Creative Commons attribution, partage dans les mêmes conditions, comment citer les auteurs et mentionner la licence, Le haut Niger reçoit les eaux des rivières, Le Niger moyen bénéficie de l'apport des affluents, Le Niger inférieur a pour affluents principaux le, Pont à Itobe, sur la route Ajaokuta-Ayangba (, Fabio Spadi, « The ICJ Judgment in the Benin-Niger Border Dispute: the interplay of titles and 'effectivités' under the uti possidetis juris principle », 2005. En 1508, sur cette carte portugaise, un grand fleuve intérieur au continent est connu. 208The Ministère des Mines et de l’Eau also has advisory committees. L'agriculture, ainsi que la pêche et l'élevage , ont conduit à l'émergence de colonies comme Djenné-Djenno dans le delta intérieur , maintenant un site du patrimoine mondial . 16.5% of the total population) in the 26 connected cities in 2002. 37However, these annual diversion figures do not show how these dams alter flows downstream. This chapter reviews the “modern” institutions and codes. There are about 60 of them. Pline l'Ancien, Histoire naturelle, livre V, I, 15. Figure 7. 35In practice, the Markala dam’s flow is governed upstream.
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