Within the Prachensko national project GIS is used for different scopes. First, an information system of the area is being built, using a raster topographical map 1:25,000 as background and displaying the positions of both the earlier finds in the area and the new field walking results. Through selecting a point or polygon on screen all the basic information on the find units is obtainable. Second, GIS is used as an analytical tool within a sort of location analysis or predictive modeling. So far, streams have been reconstructed and the relation between archaeological sites and water sources has been studied. In a similar way, it has been looked for patterns caused by geology, soil quality (18th cent. data) and the altitude. In the end, new algorithms for the automatic identification of landscape features (hilltops, areas surrounded by nature barriers, etc.) have been presented.
Fig.1. DEM of the North Prachen region with reconstructed water streams. Two categories of streams are considered according to the size of their water catchment area (1 sq. km; 0.05 sq. km). The map shows clearly that even small streams were important from the point of view of the prehistoric settlement location (black dots).