A method for classifying a terrain type in an area is provided, which comprises the steps of obtaining a plurality of overlapping aerial images of the area, calculating at least one terrain type index for each part of each of the aerial images which lies in the area, where the at least one terrain type index represents the terrain type, determining at least one terrain type index for each part of the area based on the calculated at least one terrain type index for each part of each of the aerial images, and classifying the parts of the area for which at least one pre-determined conditions is met as containing the terrain type, wherein at least one of the at least one predetermined condition relates to a value of the determined at least one terrain type index. Also provided is a system and a computer program product.