A GIS Based Methodology to Obtain the Hydrological Response to Storm Events of Small Coastal Basins, Prone to Flash Flooding

The present study aims to investigate the hydrological response of small coastal watersheds storm events. Areas around Mediterranean Sea are usually characterized by streams with intermittent flows and flash floods common. Firstly, we analyze geomorphological, soil land cover characteristics watershed in order estimate their effect on surface runoff. Furthermore, rainfall an extreme event that caused flooding past analyzed. By combining these factors, able predict this basin severe area is located island Samos, Eastern Greece, where flood events usual pose a risk areas rivers. In runoff intermittent, occurring mainly during there lack discharge or other instrumental measurements. applying SCS-CN method two largest Samos Island, through construction Synthetic Unit Hydrograph (SUH). examined record historic area, selecting large (November 2001) then obtained daily data, which used SCS for calculations. We applied methodology various parameters (e.g. lag time, time concentration, maximum discharge), also required calculation Curve Number (CN) each watershed. During (136 mm rainfall), calculated direct (excess rainfall) 44%-48% watersheds. This can be particularly useful simulating introduce better strategies management whole drainage basin.