Flood risks in a dynamic urban agglomeration: a conceptual and methodological assessment framework

The analysis of risk and its causes is a crucial prerequisite for the development of risk prevention and mitigation measures in the scope of disaster risk management. This paper investigates on the problem of annually occurring floods in Santiago de Chile applying a framework for risk assessment, especially developed for the usage in a large urban area. A case-specific set of variables and indicators was compiled to show the relevant components and their interrelations influencing the flood risk and to provide a tool for monitoring and evaluating their changes over time. Methods for gathering information about the three components of risk, that is, hazard, elements at risk, and vulnerability, comprise the interpretation of very high resolution satellite data, the analysis of GIS, and census data as well as household surveys and expert interviews. The work shows how the assessment framework can be applied in practice to derive a geodata-based flood risk map at the scale of the administrative unit of a building block that can be used as a local decision-making tool.