Research Project in Strengthening Local Authority in Risk Management. By

In the frameworks of the ITC Projects (SLARIM) Strengthening Local Authorities in Risk Management, a case study was carried out on hazard assessment on Lower Bicol floodplain. The floodplain is located in four provinces in the Philippines. It is an area frequented by Typhoons accompanied with floods. This study was carried out in collaboration with Naga City Municipality, the Philippines, In order to assist the Local authorities in the flood management. 2D flood model Delft-FLS was used to reconstruct one of the flood events caused by the Typhoon Yonning. The Model parameters were the DEM of the floodplain, the DEM of the riverbed, the floodplain and riverbed roughness, and the artificial structures. The model hydrological boundaries were the discharges at the upstream and the tidal fluctuations at the Bay. The model results were compared with water depth information, obtained from the local people, during the fieldwork that was carried out in September 2003 and previous Reports. Then several Scenarios were constructed to simulate other flood events. A methodology was then developed to transform the modelled results into hazard indicators. It was finally concluded the 2D modelling approach is useful for reconstruction of past events. The model results suggest that the flood parameters water depth and flow velocity are not very sensitive to variations in surface roughness. However physical barriers, like embankments so affect flooding significantly. V Acknowledgments The research related to this thesis and the writing process benefited from many people around the globe. Although words are not enough they appear weak and insufficient considering the contributions and strong support, nevertheless, I would like to express my sincere gratitude. First and fore most I thank ..