On the basis of the recent experience over the perifluvial areas of the Arno river (Italy), a cost effective approach is proposed to make a preliminary assessment of the flood susceptibility along urbanized rivers. This method encompass two operative phases: a rapid mapping of all the most important natural and artificial elements connected to the hydraulic risk and a reasoned analysis of the collected information with some topographic data that are usually stored in the public offices. The first step includes a field survey using a GPS (global positioning system) device in Real Time Kinematic (RTK) mode and the developing of a local geoid model whose application allows to convert the measured ellipsoidal heights in orthometric heights affected with errors ≤5 cm. Consequently a properly structured GIS geodatabase can be built in order to visualize the spatial distribution of the mapped elements and to store the most important technical data. The second step includes some analyses that allow to define all the most detailed implications for the hydraulic risk in urban and suburban areas. In particular the combination of the previously obtained orthometric heights with the available flow levels data for various return periods is able to produce the preliminary evaluation of the most dangerous dikes in terms of overflowing. Such result, joined to the surface water flow model of the urbanized perifluvial areas which relies on the processing of digital terrain data coming from LIDAR acquisitions, provides significant flood susceptibility scenarios.
A cost effective methodology for the rapid evaluation of the flood susceptibility along anthropized rivers
Morelli S.;Segoni S.;
2015
Abstract
On the basis of the recent experience over the perifluvial areas of the Arno river (Italy), a cost effective approach is proposed to make a preliminary assessment of the flood susceptibility along urbanized rivers. This method encompass two operative phases: a rapid mapping of all the most important natural and artificial elements connected to the hydraulic risk and a reasoned analysis of the collected information with some topographic data that are usually stored in the public offices. The first step includes a field survey using a GPS (global positioning system) device in Real Time Kinematic (RTK) mode and the developing of a local geoid model whose application allows to convert the measured ellipsoidal heights in orthometric heights affected with errors ≤5 cm. Consequently a properly structured GIS geodatabase can be built in order to visualize the spatial distribution of the mapped elements and to store the most important technical data. The second step includes some analyses that allow to define all the most detailed implications for the hydraulic risk in urban and suburban areas. In particular the combination of the previously obtained orthometric heights with the available flow levels data for various return periods is able to produce the preliminary evaluation of the most dangerous dikes in terms of overflowing. Such result, joined to the surface water flow model of the urbanized perifluvial areas which relies on the processing of digital terrain data coming from LIDAR acquisitions, provides significant flood susceptibility scenarios.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
