In recent years (2003), Senegal has been confronted with many urban flooding problems that have become recurrent due to the configuration of its settlement. This is due to galloping population growth, climate change a...In recent years (2003), Senegal has been confronted with many urban flooding problems that have become recurrent due to the configuration of its settlement. This is due to galloping population growth, climate change and a lack of planning and rainwater drainage networks. To fix these phenomena, Senegalese government has initiated rainwater drainage programs. In the city of Thiès, particularly in Sampathé district, flooding problem is a reality that is observed during every winter period. It is within this framework that we have proposed a project for the design and dimensioning of a rainwater evacuation network in Sampathé. The network will be integrated into a Geographic Information System for efficient management of project. This study involved identifying flood zones, determining geotechnical characteristics of the soil, and exploiting rainfall data in order to propose a storm water drainage network that will be integrated into a database management system. Thus, we carried out topographical and geotechnical studies, then designed and dimensioned the drainage network, and finally set up a geographic information system. At the end of this project, we designed a sewerage network consisting of two primary pipelines, four secondary pipelines, one tertiary pipeline, ninety-two manholes and a retention basin. To manage the network, we set up a geographic information system to geolocate various elements for rapid intervention in the field in event of a problem, make requests, generate thematic maps, and perform spatial analyses for good decision-making.展开更多
Populations of Hann Bel-Air municipality are supplied with drinking water from taps water of “Sénégalaise Des Eaux” (SDE) and Jambar pumps which capturie directly the groundwater. This municipality is char...Populations of Hann Bel-Air municipality are supplied with drinking water from taps water of “Sénégalaise Des Eaux” (SDE) and Jambar pumps which capturie directly the groundwater. This municipality is characterized by a strong environmental pollution which can affect the quality of drinking water. To determine actual quality of that water, 10 samples were taken and analyzed. Physico-chemical results have shown that tap water is more suitable for domestic consumption than Jambar pump water. The results show that physical parameters such as electrical conductivity (maximum value of 2671 μS/cm) exceed World Health Organization standard. The pH of the water from Jambar pumps is between 6.04 and 6.09, which demonstrates the aggressive character of that water. For tap water, pH values of 7.03 to 7.09 demonstrate their alkalinity. For chemical analyses, bicarbonates and sulphates concentrations respectively meet World Health Organization standards. Tap water meets World Health Organization standard for nitrates. With respect to chloride, the threshold of 250 mg/L is exceeded at all levels, but we note that high chloride concentrations are part of the exemptions granted to SDE. Tap water and water from water table have concentrations of calcium, potassium, iron and magnesium irreproachable. For sodium, EP3, EP4 and P5 samples from the web exceed World Health Organization standard with a peak of 310.27 mg/L. Tap water is more drinkable than groundwater but its quality needs to be improved and especially controlled for the well-being and sustainable health of consumers.展开更多
<div style="text-align:justify;"> <span style="font-family:Verdana;">Seismic refraction investigations have been carried out in Bakel, Eastern Senegal. The purpose was to map geometrica...<div style="text-align:justify;"> <span style="font-family:Verdana;">Seismic refraction investigations have been carried out in Bakel, Eastern Senegal. The purpose was to map geometrical relationship between the existing rock types and the Panafrican quarzitic basement, which is valuable information for the project of the Bakel fluviatile port construction. Four seismic refraction profiles were acquired. The obtained data have been processed by inversion. The obtained four seismic P-wave velocity profiles have been integrated to obtain a 3D model. By comparing the outcropping geological formations with the observed seismic data at the surface, it was possible to identify the lithology corresponding to each measured range of seismic velocity for the alluvium, the weathered bed rock, and the fresh rock. The results showed that the depth of the fresh rock of the basement varies from 0 to 18 meters above the sea level, with a deepening toward the Senegal River and toward the Northern part of the studied area. The presence of alluviums and their thickness are linked to the existence of bays and gulfs. The results of this study give valuable information for the river bed dredging cost assessment prior to the port construction phase.</span> </div>展开更多
文摘In recent years (2003), Senegal has been confronted with many urban flooding problems that have become recurrent due to the configuration of its settlement. This is due to galloping population growth, climate change and a lack of planning and rainwater drainage networks. To fix these phenomena, Senegalese government has initiated rainwater drainage programs. In the city of Thiès, particularly in Sampathé district, flooding problem is a reality that is observed during every winter period. It is within this framework that we have proposed a project for the design and dimensioning of a rainwater evacuation network in Sampathé. The network will be integrated into a Geographic Information System for efficient management of project. This study involved identifying flood zones, determining geotechnical characteristics of the soil, and exploiting rainfall data in order to propose a storm water drainage network that will be integrated into a database management system. Thus, we carried out topographical and geotechnical studies, then designed and dimensioned the drainage network, and finally set up a geographic information system. At the end of this project, we designed a sewerage network consisting of two primary pipelines, four secondary pipelines, one tertiary pipeline, ninety-two manholes and a retention basin. To manage the network, we set up a geographic information system to geolocate various elements for rapid intervention in the field in event of a problem, make requests, generate thematic maps, and perform spatial analyses for good decision-making.
文摘Populations of Hann Bel-Air municipality are supplied with drinking water from taps water of “Sénégalaise Des Eaux” (SDE) and Jambar pumps which capturie directly the groundwater. This municipality is characterized by a strong environmental pollution which can affect the quality of drinking water. To determine actual quality of that water, 10 samples were taken and analyzed. Physico-chemical results have shown that tap water is more suitable for domestic consumption than Jambar pump water. The results show that physical parameters such as electrical conductivity (maximum value of 2671 μS/cm) exceed World Health Organization standard. The pH of the water from Jambar pumps is between 6.04 and 6.09, which demonstrates the aggressive character of that water. For tap water, pH values of 7.03 to 7.09 demonstrate their alkalinity. For chemical analyses, bicarbonates and sulphates concentrations respectively meet World Health Organization standards. Tap water meets World Health Organization standard for nitrates. With respect to chloride, the threshold of 250 mg/L is exceeded at all levels, but we note that high chloride concentrations are part of the exemptions granted to SDE. Tap water and water from water table have concentrations of calcium, potassium, iron and magnesium irreproachable. For sodium, EP3, EP4 and P5 samples from the web exceed World Health Organization standard with a peak of 310.27 mg/L. Tap water is more drinkable than groundwater but its quality needs to be improved and especially controlled for the well-being and sustainable health of consumers.
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">Seismic refraction investigations have been carried out in Bakel, Eastern Senegal. The purpose was to map geometrical relationship between the existing rock types and the Panafrican quarzitic basement, which is valuable information for the project of the Bakel fluviatile port construction. Four seismic refraction profiles were acquired. The obtained data have been processed by inversion. The obtained four seismic P-wave velocity profiles have been integrated to obtain a 3D model. By comparing the outcropping geological formations with the observed seismic data at the surface, it was possible to identify the lithology corresponding to each measured range of seismic velocity for the alluvium, the weathered bed rock, and the fresh rock. The results showed that the depth of the fresh rock of the basement varies from 0 to 18 meters above the sea level, with a deepening toward the Senegal River and toward the Northern part of the studied area. The presence of alluviums and their thickness are linked to the existence of bays and gulfs. The results of this study give valuable information for the river bed dredging cost assessment prior to the port construction phase.</span> </div>
