If Saint-Louis City seems less subject to recurrent river flooding by overflow, flooding by stagnation of water from precipitation remains worrying. tion is still continuing as revealed by fig. ], "MAJOR WORLD DELTAS: A PERSPECTIVE FROM SPACE", Littoral Survey Using the JERS-OPS Multispectral Sensor: Example of the Mont-Saint-Michel Bay (Normandy, France), Assessment of shoreline changes in the western side of Zanzibar channel using satellite remote sensing, Les environnements sédimentaires du bas Sénégal après les barrages de Diama et de Manantali, Effect of hypersaline and low lake conditions on ecological functioning of St Lucia estuarine system, South Africa: An overview 2002–2008. During a major flood in October 2003, the local authorities of, Saint-Louis, Senegal, decided to open a new artificial mouth about 25 km to the north, of the existing mouth of the Senegal River, to evacuate water from the lagoon to the. From 2001, mangrove evolution remains weak (18.96%) but characterized by a drop of the disappearance (4.36%) with an increase of the regeneration (23.31%). method or the MHW (mean high water) method. shed which lead to water rise; (2) a difficult flow due to the Langue de Barbarie; (3) slowing down of discharge in the down river area; (4) the addition of marine water, to river discharge at times of heavy tides, and (5) the flat topography of the urban-, ized area. The grain objective was to test different procedures for processing multispectral data between 520 nm and 2400 nin so as to refine the information acquired from other sensors such as Spot XS and Landsat TM which have a lower spectral and spatial discrimination potential. The very high deposition rate of sediment in the breach is a testimony of the high sediment volumes supplied by the longshore transport and the high sediment released through shoreface retreat, and resulted in widening the barrier to a maximum of 1 km. from September to November 1973, 1977, 1979, 1984, 1986, 1987, 1992, 1999, 2000, Although flood is inherently associated with the Senegal River estuary, dry period from the late 1960s to the early 1990s (, influenced the urbanization in the Saint-Louis City area. a very deep river mouth with a large volume of freshwater flow beneath which a wedge of salt water from the ocean invades 1.fjord 2.salt wedge estuary 3.bar-built estuary ... is an example of a bar-built estuary. the breaching of Babagueye Island revealed in the image acquired in 2010. This paper documents the physical changes through which the lake has passed and summarises the main findings of research undertaken on the three major biotic components that have been subjected to these conditions. E. July 28, 2004. The use of multispectral satellite data enables a rapid reconnaissance of the zone where both. Bare soils with sparsely vegetated areas; 5. The flux of salt through the estuary is dominated by advection owing to the strong gravitational circulation. – Estuarine, Coastal and Shelf Science, depuis 1950. Although the amplitude is particular, ly low, due to the very flat morphology of the estuary, at a decimetre scale. This otherwise, semi-arid region of the Sahel band now has an abundant supply of freshwater all year round mostly used for irrigation and urban water supply, including for the capital cities of the two countries. A number of such examples, from South Africa have recently been published. The trend is clearly to the enlargement of the, per year. Next, the event of an exceptionally large natural breaching of a sandy spit (Sacalin spit) is used to have an insight into the sediment transport processes downdrift of the Sf. Manuscript received: September 2011; accepted: December 2011. A database was built using, the georeferenced data. The first hydraulic infrastructure was installed in 1947 to enable the Lake of Guiers to become the main water supply for Dakar. The term ``transitional waters'' first came to prominence in 2000 with the publication of the Water Framework Directive of the European Communities [European Communities, 2000. River mouths are one of the Earth’s greatest transitional environments where riverine flows coexist with wave, tidal and wind driven currents, and fresh waters mix with salty marine waters. Text: 1-877-423-2443 Email: email@example.com. Lagoons that form behind barrier islands are examples of _____. The Enhanced Thematic Mapper Plus (ETM+) is a sensor carried, sat scenes are given in path and row. Along the Langue de Barbarie important erosion of the sand dune is observed. In October 2003, the rising waters reached critical levels. The evolution of the coastline (Langue de Barbarie) shows a relatively regular, widening of the mouth (fig. the central part of the Babagueye Island that was directly submitted to the swells. The streams or rivers flowing into bar-built estuaries typically have a … Lake St Lucia, the largest estuarine lake in Africa has been subjected to hypersaline conditions and low lake levels over the past eight years following the closure of its mouth due to drought in the region. The same trend has been observed for the Sangomar breach in the Saloum, The opening of the breach in October 2003 was a political action based upon the, threat of a major flood. nates are given in meters. –. effect and the sand spit presents a skewed pattern. Spectral signatures of phytoplankton and suspended sediments are discussed in detail with accompanying discussion of why blue water (Case 1) algorithms cannot be applied to Case 2 waters. Gheorghe river mouth. The Alos PRISM data were obtained in, the frame of the Principal Investigator Pilot Project no3643 ‘Geological Mapping of Sensitive, Environments’ supported by the Japanese Space Agency (JAXA) and the European Space. ciently well-interpreted from each image. Whereas the lower part of the estuary is very flat, because of the relatively high, Fig. Each phase of these river regime changes and each step of the irrigation expansion are expressed in localised changes in the physical groundwater system. Estuaries have a life cycle. Increasingly, the retroaction from the shallow aquifer systems is observed as a rise of the saline water table. Improved management will also require transparency in the decision-making process. During the last decades, in the estuarine part of the Senegal river, noticeable hydrological changes occurred.Downstream, from Gandiol to the mouth, these changes may be related to the inlet migration as well as pronounced marine invasions during the drought of 1972–1982 but mainly to the recent coming into operation of Diama retention dam. The impact of anthropogenic breaching on coastline evolution is, 2010) and repetitivity are particularly appropriate for, 1988), and has been already demonstrated in, et al. in the dry season when storm action is weak and river flow is low. imum flow was observed at Bakel (see fig. – Thesis, Université du Maine, Angers, France, 332 pp. Some new developments, cautions have been frequently ignored. Its articles have reflected recent trends and developments within the estuarine and coastal fields and this includes the changing use of well-accepted terms. – Geobios, pathways of metazooplankton in the Senegal River Estuary (W, estuary: A definition that incorporates systems which can become closed to the ocean and, hypersaline.