Spatial and temporal analysis of land cover data in the Odra River catchment
Elzbieta Bielecka, Institute of Geodesy and Cartography, Poland
The Odra River with its floodplain forests and wet meadows constitutes one of the most important ecological corridors in Europe. Most of the river was regulated in the past but it still has many valuable forest and meadow ecosystems all along its course. The most valuable areas are the floodplain forests; their size and quality makes them one of the most unique floodplain forest ecosystems in Europe. The Odra River is 854 kilometres long; its catchment is over 118 thousand square kilometres and almost all of it (90 per cent) is situated in Poland.
The results of investigation of land cover in the Odra River catchment in various historical periods has been presented in this paper. It was mainly done by the means of GIS techniques and methods. Analysis of monographs and archival cartographic material points that the area of the Odra Valley having been managed by humankind around the end of the first millennium and the beginning of the second. It was in this period that settled lands developed, and around them agriculture. Forests and arable land were the most important land cover categories in the Odra River Basin throughout the ages. At the turn of 9th and 10th century forests occupied almost 90% of the territory. Colonisation of the area and spreading of agriculture has been achieved at the expense of forests. In the middle of 18th century the forests occupied only about 30% of the area. This situation has remained almost unchanged till the end of 19th century.
Analysis of land cover based on information obtained from historical maps and satellite images acquired in 1975, 1992 and 2000 suggests that both the means of using the land and the distribution of the main types of use (forests, arable lands, meadows, built-up areas, waters and marshes) in the Odra River catchment had not undergone major change. This confirms the supposition that land cover and land use in the area - as looked at on the regional scale and shaped hundreds of years ago (in the 13th - 15th centuries) - is an exceptionally stable configuration. While the increasing population and industrialisation did of course bring major land-use changes, these were very much confined to certain limited areas.
Keywords: land cover, Odra River, GIS