Risk Assessment and Hazard Mapping Technique in the Project for Strengthening National Strategy of Integrated Natural Disaster Risk Management

摘要

In January 2011 the mountainous region of Rio de Janeiro state was devastated by the greatest sediment disaster recorded in Brazil. In July 2013 the Government launched GIDES Project for Strengthening National Strategy of Integrated Risk Management to provide the transfer of Japanese sediment disasterrelated technology and knowledge regarding recognition, prevention and early warning in order to reduce the risk of social-economic losses. This paper describes hazard and risk assessment development carried out for 4 main sediment related phenomena : slope failures, landslides, debris flows and rockfalls. The work involved bibliographic conceptual alignment, inventory of natural disasters data and statistical data analysis. The studies allowed the definition of potential triggering angles and maximum reach distances. When these data were confronted with the Japanese parameters some adjustments were necessary to frame a more realistic synergic method, due to Brazilian field peculiarities. These procedures permitted to define hazard sediment disaster prone areas and assessment of risk. The method has been applied in five Brazilian municipalities and showed good results.