Floods have increased impacts during the last decades due to increased concentrations of population in flood risk areas in urban environment, together with effects of climate variability. Floods account for 50% of natural disasters total impacts on the population and the population most vulnerable are in developing countries. Urban population reaches 50% of total population worldwide and it has been forecast by United Nation that in 2050 urban population will be about 70%. Every person born in cities in the coming years will put strong pressure on natural resources whilst occupying small spaces with a combination of potential hazards such as floods.
The main source of flood hazard has been land use in flood risk areas and the increased frequency of floods due to impervious areas in dense urban areas. The reasons for population vulnerability in developing countries included weak Institutions, lack of urban planning and...

