THE GREAT HUNGARIAN PLAIN IN THE SHEETS OF THE HABSBURG MILITARY SURVEYS AND SOME HISTORICAL MAPS - A CASE STUDY OF THE KOROS/CRIS DRAINAGE BASIN

In this paper old historical maps and the sheets of the Habsburg Military Surveys are analyzed to distinguish different terrace levels in the Great Hungarian Plain (GHP), and particulary in the Koros/Cris river system. The GHP is located in the Pannonian Basin, in the eastern part of Hungary, which is a very flat area. Prior to the river regulations, its meandering rivers (eg. the Tisza and Koros Rivers) flooded the lower areas and created marshlands. The method of the integrated analysis of these different maps was the georeference; to geometric fit the sheets from different sources. While the First Military Survey shows the original extents of these areas the Second Survey displays the situation of the environment at the time of the flood control works in the second half of the 19th century, also with the planned cutoffs. The maps show not only the rivers, but the settlements as well. During this period, these villages and towns became bigger, so they needed more and more agricultural area. They cleared the forests and dried out the marshlands to have more ploughlands. These land types can also be separated easily in the survey sheets. Two study areas were selected to show the effectiveness of environmental reconstruction at some local engineering surveys and the Military Surveys, too. The extents of the different elevation terraces are mapped with striking accuracy.