Classification and multitemporal monitoring of rangelands in the watershed of torrent Bogdana, prefecture of Thessaloniki

In the framework of the program “Environment-Archimedes ΙΙ”, remote sensing technology and Geographic Information Systems (G.I.S.) were used for monitoring, classification and mapping of changes in the grazing forest lands of the torrent Bogdana basin. As sources of data proportional and digital thematic maps, management plans, rangeland studies and satellite digital pictures were used. The modern technologies were used for the creation of an information bank, which constitutes the source of elements for the continuous follow-up and management of the region. The torrent Bogdana basin belongs to the group of basins of Koronia and Volvi Lakes in Lagadas region and covers a total area of 17.900 ha. The study area was distinguished in different land cover categories. The rangelands constitute the largest category of land cover in the total area of the basin. In this work the diachronic changes of rangelands in period of 1989-2000 are presented. The diachronic study showed a reduction of grasslands to other categories, with more important the increase of evergreen shrublands and of agricultural land. The results indicated that remote sensing is indicated method for producing geographic data for the study of diachronic changes of grazing areas in the basin of torrent Bogdana and its use can help in better management of the environment.