Damage assessment in townships using VHSR data; The effect of Operation Murambatsvina / Restore Order in Harare, Zimbabwe

Operation Murambatsvina, also known as Operation Restore Order, has been a country wide operation carried out by the Zimbabwean Government of forced mass evictions, the demolition of homes and informal businesses. This paper presents first steps towards a transferable and robust change analysis approach for detecting and quantifying damages. The method used for damage detection combines object-based image analysis and GIS analysis. We use a workflow for information delivery, which is built upon (1) a transferable urban feature extraction scheme using very high spatial resolution (VHSR) before and after images, and (2) spatial aggregation of the results for comparative change detection and analysis. The aggregated change of urban area between 2004 and 2005 was calculated for 90 raster cells (500 * 500 m). Six cells could be identified with a standard deviation > 3 as areas with significant change. Visual inspection revealed four cells indicating destruction sites, two cells referring to an industrial area with high variation in industrial activity. This approach is expected to significantly improve rapid mapping and the detection of affected areas that require further interpretation and critical review.