Three dimensional modeling for flood communication : an exploratory case study using flood extent data from the Testebo River in Gävle, Sweden

Sammanfattning: Residents of high-risk flood areas are often unaware and unprepared for extreme flood events. In order to raise awareness and improve preventative measures, methods of communicating the potential hazards, vulnerabilities, and risks associated with flood events need to enhanced. Geovisualizations that incorporate three-dimensional (3D) models of urban environments are being applied more frequently to improve communication of potential flood events to members of the lay-public. Recent studies suggest that the interactive and explorable environments provided by 3D geovisualization tools allow users to visualize complex geospatial data in a manner that is more easily understood than traditional 2D maps. The aim of this study was to examine the use of a 3D model for the purpose of communicating predicted flood levels in residential areas. An exploratory case study was conducted to construct and evaluate a 3D model of previously calculated data from the Testebo River in Gävle, Sweden. Methods for creating the model were developed with information obtained from in-depth literature reviews, and consultations with GIS professionals. To evaluate the communicative ability of the model, usability tests were conducted on a small sample size of participants. Through these processes, an explorable 3D model that represented the 100-year and highest probable flood scenarios in the residential areas of Varva, Strömsbro, Forsby and Stigslund was created. The results of the usability tests indicated the model was an effective visualization and provided appropriate tools for exploration. Although the study identified some limitations of the model and 3D models in general that should be considered, it also provides a valuable foundation on which to develop further studies of 3D models for flood communication purposes along the Testebo River and in other flood-prone areas.