 |
| Titel |
Reconstruction of a Holocene average catchment denudation from the landslide-dammed lakes in the Outer Western Carpathians |
| VerfasserIn |
Tomáš Pánek, Veronika Smolková, Jan Hradecký |
| Konferenz |
EGU General Assembly 2010
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250040110
|
|
|
|
|
|
| Zusammenfassung |
| In the mid-mountain region of the Outer Western Carpathians, fossil landslide-dammed lakes
with preserved sedimentary sequences are the key sources of information about the Holocene
geomorphological conditions. Importance of the landslide-dammed lakes as data sources lies
particularly in i) dating of the related landslides, ii) study of the palaeoenvironmental
conditions, iii) quantification of the sediment budgets and iv) understanding risks
connected with landslides. Most of the studied sedimentary records contain frequent
variations in sediment genetic type (e.g. lacustrine anorganic clay and silt, organic
gyttja and peat of swampy facies with often minerogenic intercalations, fluvial
sub-rounded gravel, etc.), which well document dynamic changes in the type of
geomorphic processes in the contributing catchments. Radiocarbon dating together
with the palynological and sedimentological analyses detect the repeated changes
in the depositional conditions connected with the palaeoenvironmental changes
during the Holocene. Results of the radiocarbon dating of the lake sediments’ basal
parts show that landslides causing the valley damming originated throughout the
whole Holocene with significant increase of landslide activity in the Subatlantic
chronozone. For the understanding of the relief development dynamics throughout
the Holocene, linear lake sedimentation rates and minimum average catchment
denudation for selected contributing catchments in different time spans were calculated.
Minimum mean mechanical denudation of landslide-dammed catchments varies
between 2.5-13.4 mm.ky-1. Obtained denudation rates well correspond with the other
researches on erosion rates in the studied region: mean total denudation rates = 39-79
mm.ky-1, 79-158 mm.ky-1, 120 mm.ky-1, 280 mm.ky-1 for the Outer Western
Carpathians; mean mechanical denudation rate = 15-30 mm.ky-1 for the Central Europe,
respectively.
This research was supported by a project from the Grant Agency of the Czech Republic,
No. P209/10/0309: “The effect of historical climatic and hydrometeorological extremes
on slope and fluvial processes in the Western Beskydy Mts. and their forefield”. |
|
|
|
|
|
|