Fire detection in informal settlements

Multi-dwelling fires in informal settlements in South Africa are devastating for residents resulting in loss of life, homes and belongings. The aim of the IRIS-Fire project is to develop innovative methods of assessing and modelling fire risks with the goal of increasing informal settlement fire resilience. This paper outlines a new approach to mapping historic and ongoing fires in informal settlements using satellite imagery. A theoretical informal settlement fire curve for albedo is proposed based on the predicted reflectance of roof materials pre- and post-burn. Landsat OLI imagery in Google Earth Engine is used to map time series of albedo and the method is tested for a pilot site in Masiphumelele, South Africa. Results indicate that the detected albedo time series matches the theoretical informal settlement fire curve to some extent. Further research will investigate using (1) higher spatial resolution satellite data to reduce the impact of the mixed pixel effect, (2) higher temporal resolution satellite imagery such as Sentinel-2 to increase the revisit time and thus increase the number of high quality images, and (3) dark object subtraction to minimise scene noise, (4) use of statistical quality control charts to detect statistically significant change.