Alassane Thiam^1,, Pape Sanou Faye¹, Serigne Modou Sarr², Dieyni SY Diallo³

In October 2003, the city of Saint-Louis, a UNESCO World Heritage Site, was to be swallowed by the rising waters of the Senegal River. That is why, the public authorities and the communal authorities wanting to find an immediate solution to save the city and human lives, took the decision to create a channel of load shedding on the Barbary language called breach. This urgent political decision seems to have profoundly modified the hydrological behavior of the Senegal River in Saint-Louis. The breach opened in Saint-Louis to counter the flood phenomenon, has since the night of October 3 to 4, 2003, the date of its opening, caused many environmental problems resulting from profound changes in the biophysical characteristics of the area (floods, loss of biodiversity). However, many specialists are still thinking about the issue but still do not find sustainable solutions to restore the balance. The aim of this study is to propose technics for stabilizing the area with two specific objectives such as understanding its evolution and evaluating the threats to the neighbouring villages. This study on the evolution of the breach from 2003 to 2013 is based is conducted by analysis of samples taken from the Langue de Barbarie and the breach to determine their type. The main results show that the soil is sandy, which has made it possible to propose structural and non-structural stabilization methods. The compilation of the different results shows two types of stabilization (structural methods and non-structural methods). The two methods constitute for each of them, a durable alternative solution for the stabilization of the breach in order to limit the environmental damages. Meanwhile, it would be important to monitor the structure by annual analyzes of the structure.

Saint-louis, flood, breach, environment, structural methods, non structural methods