"Catastrophic Risk Assessment, Using Integrated Multi-Criteria Flood Vulnerability Index for Various Spatial and Temporal M ining Scales : A Case Study of Kosi Flood Affected Five Districts"

Abstract

Human population worldwide is vulnerable to natural disasters, which are increasing due to the consequences of socio-economical and land-use developments and due to climate change. In recent years the impacts of floods have gained importance because of the increasing amount of people who are affected by its adverse effects. In this study a methodology to compute a flood vulnerability index, based on indicators, is developed, aiming at assessing the conditions which favour flood damages at various levels: river basin, sub-catchment and urban area. This methodology can be used as a tool for decision making to direct investments at the most needed sectors. Its implementation could guide policy makers to analyse actions towards better dealing with floods. The methodology involves two concepts. First, vulnerability, which covers three related concepts called factors of vulnerability: exposure, susceptibility and resilience. The other concept concerns the actual flooding; understanding which elements of a system is suffering from this natural disaster. Three main components of a system are recognized which are affected by flooding: social, economical and environmental The interaction between the vulnerability factors and the components serves as the base of the proposed methodology. The methodology has been applied in various case studies spatial and temporal scales, which resulted in interesting observations on how vulnerability can be reflected by quantifiable indicators. The testing results indicate that the FVI of a river basin as a whole can be better reflected by the average FVI of its sub-catchments, thereby improving decision-making processes at regional levels. However, the average FVI of urban areas does not reflect the FVI of the sub-catchment or river basin in which they are located.