Introduction

As demonstrated by well-known disaster statistics (e.g. EM-DAT, 2008), the world is confronted with a rapidly increasing impact of disasters, many of those derived from geomorphological extreme events. The possible impact of hazardous events can no longer be ignored and there is an urgent need to include the concepts of disaster risk management into spatial planning, environmental impact assessment (EIA) and strategic environmental assessment (SEA). Tools need to be developed to evaluate the possible losses given different scenarios of development and climate change, which may lead to different patterns of risk than those that are prevalent today (IPCC, 2007). The Hyogo framework of action 2005–15 of the United Nations International Strategy for Disaster Reduction (UN-ISDR) indicates a number of priority actions for disaster risk reduction in the coming decade. One of these is to ensure that disaster risk reduction is a national and a local priority with a strong institutional basis. Another one is to identify, assess, and monitor disaster risks and enhance early warning. Disaster risk management requires the assessment of risk, which is a multi-disciplinary endeavor embedded in a good culture of risk governance involving all stakeholders (UN-ISDR, 2005).

The evaluation of the expected losses due to hazardous events requires a spatial analysis, as all components of a risk assessment differ in space and time. Therefore hazard, vulnerability, and risk assessments can only be carried out effectively when use is made of tools that handle spatial information, such as geographic information systems (GIS).