Examining GIS decision utility for natural hazard risk modelling

The research examines the incompatibility between resolution and scale of spatial data in a spatial modelling environment and the resolution and scale of human spatial decision-making. This incompatibility is rarely considered when a geographic information systems (GIS) is applied to natural hazard risk assessment. However, the ultimate success of a risk management project should be assessed in the context of improved decision-making. Decision utility is an emerging theme in GIS literature that focuses on cognitive issues of GIS and human interactions. The research presents a technique for flood risk modelling using GIS and digital elevation models to map relative risk in urban communities. The study is based on Cairns located in far northern Australia. The risk model accounts for uncertainties inherent in the elevation data by adapting an existing error simulation technique. Techniques for making spatial model assumptions and model error explicit to flood risk managers are introduced and evaluated for risk management decision-making.