Kim M. Cohen
Kim M. Cohen PhD
visiting scholar 2003-2004from January 2005 at:
Department of Physical Geography
PO Box 80.115
3508 TC Utrecht
- Activities (2003-2004) for Global database of Fluvial activity in Last Glacial and Holocene
- Previous work : Late-glacial and Holocene of the Rhine-Meuse delta in the Netherlands.
- Current activities (2005-present)
In this first year, focus is on the development of a database that has both a bibliographical component, a site-data component and a pathway component for 21 ka BP, covering Eurasia.
Fig. 1: Typical field data
The database in principle allows for systematic evaluation of climate model output versus field-evidence for selected time frames over continental scales. The approach also is a strong test of the internal consistency of local fluvial reconstructions over larger stretches of river.
A project report has been produced and delivered to co-workers within the bigger climate model evaluation projects. It is expected to become online-on-request via PMIP's site in the near future. We are currently (January 2005) still deciding on how to continue this project.
1. The number of geomorphological/geological channel units
that are generally identified within a middle-lower valley reach of the river, spanning the last 50.000 years. Usually there are 3-6 identified units, e.g. "Pleniglacial river bed/terrace", "Tardiglacial river bed/terrace", Early-Middle Holocene river bed, Modern (historic) river.
|2. For each of these units, we need estimates of|
o Channel bed (terrace) palaeo-width [ e.g. 6.5 – 6.8 km ]
|3. For each of these units, we need estimates of|
o The age of abandonment of this deposit
|4. Bibliographic references to the original data-sources on which this record is based.|
This webpage serves as a project outline summary. The results of the pilot-project described above are further document in:
Cohen, K.M. (2004) Global Continental Drainage project report: A database on field records of rivers of the last 50 ka, for palaeo-discharge estimation and GCM intercomparison. Palaeoclimatology group, Max Planck Institute for Biogeochemistry, Jena, Germany / PMIP-2 Paleoclimate Modelling Intercomparison Project Phase II / DEKLIM project Past Climate Sensitivity and Variability Project. 86 pp.
The project as such was not actively continued.
Elements of the proposed approach have found continuation in the setup of a database for the Lower Rhine system:
Cohen, K.M., Wallinga, J., Busschers, F.S., Hoek, W.Z., Kasse, C., Jones, A., Rhodes, E., Macklin, M.G., Benito, G. (2009) Regional database of Lower Rhine OSL dates in sedimentary context: Can we unravel preservation and sampling bias from climatic depositional overprints? 27th Meeting of the International Association of Sedimentologists, Alghero, Sardinia, Italy. Oral presentation.
GIS-based palaeoenvironmental reconstruction
From 1998 on Kim worked on the late Quaternary of the Rhine-Meuse delta (the Netherlands) at the Physical Geography department of Utrecht University. From 1998-2001, he worked with colleages Berendsen & Stouthamer, to implement their palaeo-geographic reconstruction of Holocene distributary channel belts in a GIS. This GIS was then used to cross-check the reconstruction and to produce a geological map and a series of 16 palaeo-geographical maps of the Rhine-Meuse delta , published as poster-sized coloured maps by Berendsen & Stouthamer (2001, Add. 1 & 2).
Since 2000 the GIS database has proved to be useful in many projects by third parties (e.g. to produce indicative maps of archeological value and in prospecting studies for new railways and highways). Kim has continued to manage this GIS at the Utrecht department of Physical Geography during his time as a PhD student (1999-2003).
|Geological - geomorphological map (fragment)||Palaeogeographic maps (same area)|
Holocene delta distributaries colored by their age of abandonment. Result of GIS implementation of reconstruction by Berendsen & Stouthamer (2000, 2001).
Depicted are 5 out of 16 maps that were created using the same GIS-data as were used for the map to the left. Timeframes shown: 10,000 - 7,000 - 6,500 - 6,000 - 5,500 ka BP (14C ages)
Green: 7-4 ka BP. Yellow: 4-2 ka BP. Red: 2 ka BP-present (all 14C ages)
Orange: active channel belts. Green: abandoned channel belts
Lighter tones: later eroded/reworked parts. Darker tones: preserved parts.
Central Rhine-Meuse delta: detailed mapping of alluvial architecture
Fragment of Addendum 2 to Ph.D.-thesis (c) Cohen, 2003 . A full version is for download via Utrecht University library (as a PDF) .
full description in Cohen, 2003 : Ch. 5
||Floodbasin peats, gyttjas and strongly humic clays of Holocene age: Distal floodbasins and residual channels|
||Eolian sand of latest Weichselian Lateglacial age: Younger Dryas inland source-bordering dunes.
||green :||Fluvial clays of Holocene age: Distal floodbasins, distal crevasse-splays .
||Clays with admixed sand of Weichselian Lateglacial and early Holocene age: Floodplain overbank areas .
|Fluvial sandy and silty clays of Holocene age: Proximal floodbasin levees, crevasse-channels and -splays .
|Gravels and gravelly sands of Weichselian Pleniglacial and Lateglacial age: Burried terraces and incised channel belts.
||Fluvial sands of Holocene age: Channel belts of Meuse (left) and Rhine (right) .|
Selected publications related to the 1999-2003 work described above:
Berendsen & Stouthamer (2001) Palaeogeographic development of the Rhine-Meuse delta, The Netherlands. Assen: Van Gorcum 268 pp + addendums. ISBN: 90 232 369 5. Containing:Berendsen, H.J.A., K.M. Cohen, E. Stouthamer (2001) Maps and cross-sections. p. 49-55.
Berendsen, H.J.A, K.M. Cohen & E. Stouthamer (2007). The use of GIS in reconstructing the Holocene paleogeography of the Rhine-Meuse delta, The Netherlands. Int. J. of GIS, 21, 589-602.
Cohen, K.M. (2003) Differential subsidence within a coastal prism. PhD-thesis. Dept. Physical Geography, Utrecht University. Published as: Netherlands Geographical Studies 316 176 pp. ISSN: 0169-4839.
Cohen, K.M. (2005) 3D geostatistical interpolation and geological interpretation of palaeo-groundwater rise within a Holocene coastal prism. In: L. Giosan, J.P. Bhattacharya (eds). River Deltas - Concepts, models, and examples. SEPM Special Publication 83, p. 341-364.
Cohen, K.M., E. Stouthamer, H.J.A. Berendsen (2002) Fluvial deposits as a record for neotectonic activity in the Rhine-Meuse delta, the Netherlands. Geologie & Mijnbouw / Netherlands Journal of Geosciences 81 (3-4), 389-405.
Cohen, K.M., M.J.P. Gouw, J.P. Holten (2005) Fluvio-deltaic floodbasin deposits recording differential subsidence within a coastal prism (central Rhine-Meuse delta, the Netherlands). Chapter 11 in: Blum, M.D., S.B. Marriott & S.F. Leclair, eds. (2003), Fluvial Sedimentology VII. Special Publication 35, International Association of Sedimentologists. Blackwell Scientific.
An up to date overview of activities (2005-2008: Post doc; 2009 - present: Assistant Professor Utrecht University)
- River databasing activities are continued, amongst others in FLAG / GLOCOPH context.
- Paleohydrological activities are continued, with shifted focus to the Rhine delta apex and focusing on the rare-high magnitude individual events as recorded in the sedimentary record. PhD Candidate W. Toonen (UU and Deltares, in cooperation with TNO)
- Holocene Rhine-Meuse delta activities are continued, extending the covered area in upstream and downstream directions, aiming at integration of understanding of the delta environment and its internal variation to the coast and valley environments downstream and upstream. Includes supervision of PhD candidates G. Erkens, M.P. Hijma (both defending in December 2009).
- Projects connecting the Pleistocene Rhine record, the Southern Bight erosion record and the glaciation history of the North Sea Basin in the last 500.000 years have been launched. Includes cooperations with F.S. Busschers (VU Amsterdam, now at TNO Geological Survey of the Netherlands) and P.L. Gibbard and co-workers here at Cambridge, and E. Bregman (Province Drenthe, UU) and MSc students at UU. Includes projects linking geology, geomorphology and paleolithic archaeology, offshore and onshore.
- Database and GIS expertise to deal with mapping information, to weed through vast amounts of shallow subsurface data and assemble subsurface models is build out, in close cooperation with 3D Geomodelling group at TNO Geological Survey of the Netherlands.
- I combine research with teaching the sedimentary side of Quaternary Geology to BSc, MSc and PhD students.
Discharge data of the river Allier at Moulins (central France) related to M.Sc.-thesis (1998, Physical Geography, Utrecht University). MS-Excel graph, created in 1998 for Antoine Wilbers.