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001-es BibID:BIBFORM065989
Első szerző:Bertalan László (geográfus)
Cím:Soil degradation induced by lateral erosion of a non-regulated alluvial river (Sajó River, Hungary) / Bertalan László, Szabó Gergely, Szabó Szilárd
Megjegyzések:The aim of this study was to reveal the spatial and temporal changes of the lateral migration of Sajó River and reveal their impacts on the rates of soil degradation that affects the surrounding agricultural lands.Sajó (in Hungarian) or Slaná (in Slovakian) is a Slovakian-Hungarian river with a total length of 229 km, of which 124 km is situated in the Hungarian territory. In Slovakia it is the main river of the southern part of Slovenské Rudohorie Mountains, part of the Cerová vrchovina uplands and the Rimavská kotlina hollow basin. Its source is situated in the Stolica Mountains range of the Slovak Ore Mountains. It flows through the Slovak town Ro?z?nava and the Hungarian city Miskolc. According to the rate of regulated sections the Sajó River is unique since only the one third of the Hungarian section has anthropogenic intervention. Long term morphological changes of Sajó River were evaluated on the basis of maps, aerial photographs (1952, 1956, 1972, 1988, 2000, 2005 and 2011) and the 1:10.000 scale topographic map of Hungary (1980). In every investigated periods the bank edges were vectorized in ArcGIS then variables (i.e. centerline length, width, chord length, amplitude, sinuosity, radius of curvature) of channel planform morphometry were calculated for each bend. Overlaying banklines in each consecutive periods allowed us to calculate lateral migration polygons with the purpose of analyzomg the spatio-temporal changes in the rates of erosion and accretion. In 4 selected bends and meanders detailed UAV surveys were performed between April 2014 and August 2016 to identify the rate of bank retreat. The centerline analysis of Sajó River shows an outstanding shortening between 1952 and 1980 related to the regulation works at few bends performed by several industrial purposes. After 1980 the centerline-length started to increase and we suggested that it could be a reason of new meander-development along the river. Our results showed that the channel width had a decreasing trend; while the bend length increased as well as the sinuosity since 1980 due to meander development. However, the number of bends increased in every sections but their evolutionary state increased with a lesser rate. It turned out, based on the analysis of the long-term lateral migration polygons, that the rate of erosion and the soil degradation of agricultural lands had fluctuated and there is an increase in the trend from 2000 (9 ha/year was measured between 2005 and 2011). Mainly the higher rate of erosion is connected to the free-forming meanders and these bends are in agricultural use; thus, this process cause substantial damage of property.According to the results of UAV monitoring the short term development of the selected bends and meanders and the rate of lateral erosion was very active, 4.5 meters/year (1952-2016) and in some places about 2.4 meters/month while the maximum was 31 meters in 14 months. Outstanding bank failure events also occurred, especially in Sajószentpéter when the spring flooding of 2016 resulted approx. 400 m3 material displacement from one bend in a 6 months long interval.
ISBN:976 80 86407 65 4
Tárgyszavak:Természettudományok Földtudományok előadáskivonat
lateral erosion
fluvial geomorphology
soil degradation
Megjelenés:Aktuální environmentálni hrozby a jejich impakt v krajiné = (Current environmental threats and their impact in the landscape Brno): Sbornik abstraktu z mezinárodniho workshopu / ed. Jana Zapletalová, Karel Kirchner. - p. 8-9. -
További szerzők:Szabó Gergely (1975-) (geográfus) Szabó Szilárd (1974-) (geográfus)
Pályázati támogatás:RH/751/2015
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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