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| Titel |
Upland catchment response to base level lowering, climate and dam events. A combined field and modelling approach. |
| VerfasserIn |
Wouter van Gorp, Jeroen Schoorl, Arnaud Temme, Tony Reimann, Jan Wijbrans, Darrel Maddy, Tuncer Demir, Tom Veldkamp |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250115059
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| Publikation (Nr.) |
 EGU/EGU2015-15916.pdf |
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| Zusammenfassung |
| Combining field reconstruction and landscape evolution modelling can be useful to
investigate the relative role of different drivers on catchment response. The Geren Catchment,
a small (~45 km2) upland catchment in western Turkey is a suitable catchment for such
a study. This catchment endured gradual Quaternary uplift-driven incision of its
trunk river, the Gediz. Additionally, fieldwork and dating results show that its outlet
has been dammed repeatedly by lava flows since ~300 ka, resulting in infrequent
base level rise and fall. Incision of the Geren trunk gully has been delayed until at
least the end of MIS 5, after which an incision phase lowered the Gediz by around
30 m. Subsequent erosion and aggradation sequences demonstrate how the Geren
Catchment has responded to base level lowering at least since MIS 4 by stepped net
incision. Field reconstruction left us with uncertainty about what the main drivers of
terrace formation were, therefore, possible scenarios were simulated using landscape
evolution modelling. Three scenarios of landscape evolution in the Geren Catchment
were investigated: i) uplift with climate (rainfall and vegetation based on arboreal
pollen), ii) uplift, climate and short damming events and iii) uplift, climate and long
damming events. Output was evaluated for erosion-aggradation evolution in trunk
gullies at two different distances from the catchment outlet. Climate influences
erosion – aggradation activity in the upstream reach, although internal feedbacks
influence timing and magnitude. Lava damming events leave an aggradation signal in
the downstream reach, while complex and lagged response to these dams obscure
correlations with climate and leave a legacy on current landscape evolution. Catchment
response to long damming events correspond best with field reconstruction and
dating. The combination of climate and base level explains a significant part of the
landscape evolution history of the Geren Catchment. By combining model results
with fieldwork, additional conclusions on landscape evolution could be drawn. |
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