RECENT DEVELOPMENT OF JELENÍ POTOK BROOK CHANNEL AND FLOODPLAIN

Recent morphologic development of channel and floodplain of Jelení potok brook (left side tributary of the Opava river) was analyzed in thesis. Anthropogenic-modified channel (more than 80% of total channel length) is distinctively altered by erosional flood-induced landforms (bank failures, flood channels) that were predominantly created during flood in 1997. Some landforms, however, emerged during precedent flood events (1995, 1996). This fact was confirmed by dendrochronological research. An analysis of exposures of alluvial sediments shows higher dynamics of channel shifts in the past, followed by period of fine-grained sediment accumulation. Dating of charcoal deposed in flood-loams (depth 59 cm, age 820±30BP) enables to estimate dynamics of floodplain accrecion. The beginning of floodloams deposition is thus dated to medieval ages. An analysis of landscape cover changes between 1840 - 2002 shows that current forest area (58%) and permanent grasslands (18%) are achieving its maximum extent during last 160 years. On the other side, the extent of arable land (19%) has gradually falled to current miminum area. In long-term period, this fact could lead to channel incision. Powered by TCPDF (www.tcpdf.org