期刊名称：Acta Geographica Debrecina. Landscape and Environment Series
印刷版ISSN：1789-4921
电子版ISSN：1789-7556
出版年度：2009
卷号：3
期号：1
出版社：University of Debrecen
摘要：Land-use changes and their effect on overbank sediment accumulation wereinvestigated on the floodplain of Middle-Tisza River.Military survey maps (1783, 1860, 1883 and 1890) and aerial photos (1950, 1965, 1980 and 2000) were used to evaluate land-use changesand to calculate the vegetational roughness of the area. To determinate the rate of overbank sedimentation sediment samples were collected from a pit, the grain-size, content of organic matter, heavy metal content (Pb, Cu, Zn, Ni and Cd) and pH weremeasured.Until1950 meadows and pastures were typical on the floodplain, gallery-forest was along the river, the oxbow-lake and the artificial levee. Notable land-use changes were detected inthe second half of the 20thcentury, as the aerial photo taken in 1965shows extensive forestry in thearea. These land-use changes affected the average vegetational roughness, as it has been doubled since the disappearance of grasslands. Land-use changeshighly affect the aggradation, as the increased roughness decreases the flood velocity on the floodplain, causing accelerated aggradation. Using Pb marker horizonsand grain-size changes the studied sediment profile was compared to dated profiles(Braun et al. 2003), thus, the sediment accumulation rate could be determined for the periods of 1858-1965 and 1965-2005. According to our measurements the accumulation rate was doubled since 1965, very likelyin connection with thedoubled vegetationalroughness
