As identified in the objectives, we examined the potential of OOA to map complex gully erosion features and established the topographical and image thresholds for a given area, to develop a generic method for semi-automatic gully detection to map the gully extent. Initial classification of all background classes eliminated areas of non-interest, thus improving the performance of classification processes by limiting subsequent steps to the unclassified region. Segmentswith SCA≤40 m2 and areaswith slope gradientsb3°,where surface runoff generation and accumulation are assumed to be insufficient for gully initiation, were removed.