COMPARAISON ENTRE LA NOUVELLE-ORLEANS ET SAINT-PETERSBOURG :DES RISQUES SIMILAIRES

New Orleans (the United States of America) and Saint Petersburg (Russia) have many similarities, geological, ecological and because of their proximity with the sea, are confronted to many similar risks, in particular by flooded and hurricanes. The great planning plans of the territory started at the 17th century, intended to make New Orleans livable and more secure, caused deep geomorphological and ecological unbalanced till the Gulf of Mexico. These changes, since this date, accentuated and increasing the risks whose is prone New Orleans and others Parish. When the hurricane Katrina hit Louisiana in 2005, it flooded many Parishes of the Gulf of Mexico, from Alabama to Texas. The field studies however showed that the circumstances of the flood of the neighborhood of Lower Ninth Ward, are not simply due to the climatic phenomena, but to a conjunction of events in foreseeable parties. Concerning Saint Petersburg, the hurricanes coming from the Gulf of Finland cause hydrological disturbances which make rise the level of water in the Neva bay at the origin of serious and regular floods. The first studies conducted in Saint Petersburg in August 2011, made it possible to highlight serious faults in the protection system. Saint Petersburg, is composed of 42 islands, and the first observations revealed inconsistencies near some banks, in particular on the level of Vasileostrovskiy Island. The object of this first work is to show the common points existing between New Orleans and Saint Petersburg starting from the observations on the two sectors.