Evaluating cartographic design in flood risk mapping

Abstract

In order to mitigate flood hazards and to minimize associated losses, technical protection measures have been additionally and increasingly supplemented by non-technical mitigation, i.e. land-use planning activities. This is commonly done by creating maps which indicate such areas by different cartographic symbols, such as colour, size, shape and typography. Hazard and risk mapping is the accepted procedure when dealing with natural hazards and is therefore required in the European Member States in order to meet the demands of the European Flood Risk Directive. However, available information is sparse concerning the impact of such maps on different stakeholders, i.e. specialists in flood risk management, politicians and affected citizens. The lack of information stems from a traditional approach to map production which does not take into account specific end-user needs. In order to overcome this information shortage the current study used a circular approach such that feedback mechanisms originating from different perception patterns of the end user would be considered. Different sets of small-scale as well as large-scale risk maps were presented to different groups of test persons in order to (1) study reading behaviour as well as understanding and (2) deduce the most attractive components that are essential for target-oriented communication of cartographic information. Therefore, the method of eye tracking was applied using a video-oculography technique. This resulted in a suggestion for a map template which fulfils the requirement to serve as an efficient communication tool for specialists and practitioners in hazard and risk mapping as well as for laypersons. Taking the results of this study will enable public authorities who are responsible for flood mitigation to (1) improve their flood risk maps, (2) enhance flood risk awareness and, therefore, (3) create more disaster-resilient communities.