6. Geo-Information Technology for Infrastructural Flood Risk Analysis in Unplanned Settlements: A Case Study of Informal Settlement Flood Risk in the Nyabugogo Flood Plain, Kigali City, Rwanda

The main objective of this research was to improve flood mitigation within Rwanda’s rapidly growing Kigali City using Geo-Information Technology (GIT) to identify flood hazard zones, analyze flood exposure and vulnerability, and suggest planning interventions. Multiple sources of data and methods were utilized including a very high resolution Quickbird image, Global Positioning Systems, interviews and a survey that aided flood hazard zone delineation, flood depth interpolation and mapping. The flood exposure analysis incorporated vulnerable infrastructure, buildings, population and economic activities and revealed that 27% of buildings were located in flood prone areas. Additionally, two sensitive sectors of infrastructure, four sensitive economic sectors and approximately 500 people were identified as vulnerable. The results influenced policy because Kiruhura’s major market was relocated to a new site and new urban developments were restricted from building within the flood way. The study developed a model for flood risk analysis adapted to the specificity of Kigali City, demonstrating the need to explicitly incorporate these risks into the recently developed Kigali City Master Plan. The research stresses the importance of the integration of flood risks (and natural risks, in general) into major national development strategies, policies and laws related to Rwanda’s urbanization.