Decision Support Framework Integrating Spatial Information for Building Flood Retrofit

Abstract

As the climate changes, raising the frequency of stronger thunderstorms, the flood risk that metropolitan cities face will only intensify. With ongoing informal settlements and ever-increasing changes in the land use, building assets that are not exposed to flooding will eventually find themselves within floodplains. As an attempt to adapt buildings to withstand future events and decrease their vulnerability, researchers and government agencies have developed various flood retrofit strategies. However, the implementation in urban areas is not always feasible or appropriate due to insufficient geospatial consideration in the decision-making process.

The present research aims to provide a decision support framework combining spatial aspects, along with all influencing factors to derive suitable retrofit solutions for homeowners. Through Geographic Information Systems (GIS), spatial characteristics are first extracted as data prerequisite, then inserted into the analytic hierarchy process (AHP) for an efficient evaluation of appropriate structural measures against flood. To ensure the effectiveness of the framework process, a study of a residential house is conducted in Kinshasa, the capital city of Democratic Republic of Congo, which regularly endures severe inundation.

As research results, digital maps of exposed buildings are provided, as well as recommendations of most suitable retrofitting options for the case study. Not only the simplified GIS-based calculation approach can be used to generate flood impacts without specialist knowledge, but also government authorities and managers can take advantage of the framework process to suggest tailored solutions for homeowners, actively involved in the process.