Flood risk modelling with LiDAR technology

Abstract

Floods are one of the most serious, common and costly natural disasters that many countries are facing. Climate change and growing urban areas have dramatically increased the frequency and the severity of flood events. This has enhanced the interest of the Scientific Community and of public institutions into creating more accurate studies regarding the delineation of possible flood areas. In mountain and hill areas, it is much easier to mark the flood areas even with a one-dimensional scheme, while in lowlands the accurate delimitation of flood areas becomes much more difficult requiring a more detailed description of the territory. In particular, the definition of flood areas in coastal zones is extremely difficult because of the small changes in the land surface elevation and because of the presence of manmade structures that may significantly modify flood distribution. The area of study is the Ionian coastal plain of the Basilicata region (Southern Italy) crossed by five of the six main rivers of the region (Bradano, Basento, Cavone, Agri and Sinni). This work aims to: analyze the capacity of LaserScan data for the description of coastal morphology and to model flood risk areas; define a DTM able to describe the channel and floodplain morphology working on high resolution laser altimetry data and topographic data; define the most effective strategy for the delineation of flood areas using the comparison of the one dimensional model (Hec-Ras developed by the Hydrologic Engineering Center of USACE) versus the two dimensional scheme (MIKE 21 HD by the Danish Hydraulic Institute, FLO-2D by O'Brien (FLO-2D User Manual.