Natural hazards, on a national and international scale, have increased in the last years as a consequence of climatic changes and human activity resulting in an unfavourable impact on socio-economic conditions. Catastrophic phenomena related to river floods as well as, from erosional and meteorological events, and

human intervention. The Vulnerability being particularly high in the regions intensely populated, like the analyzed case study, high is the Risk. The importance of geomorphological studies in assessing natural hazards due to river floods was brought into focus with recent floods event that occurred in urban areas in NW Peloponnesus, Greece. During the autumn and winter months intense rainfalls persisted for several hours producing severe flash flood

mainly in the alluvial playing of same urban streams - river. There were some loss of life and damage to buildings, transport infrastructure and agricultural crops. The damages are mainly due to absence of good alluvial playing

management practices in recent decades, concretely after the year 1960 during the urban growth of towns. The most commonly visible consequences of the land-use change are flash floods observed in urban areas after high precipitation events. As important as the value of runoff formed from the watershed, is the process of reconstruction of the shape of the runoff hydrograph, especially the estimation of the time and value of the peak flow.