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![sedimentation rate [mm/yr]
floodplain sedimentation
Increase of mean SR
since approx. 2000 BP
strong human impact
baseline SR: 0.5 mm/yr
Hoffmann et al. (2009, Catena)](https://image.slidesharecdn.com/geocensthomashoffmanpresentation-101008095757-phpapp02/75/GeoCENS-presentation-on-The-need-of-spacial-data-in-geoscience-and-GeoCENS-by-Thomas-Hoffman-in-Banff-September-23-2010-11-2048.jpg)
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GeoCENS presentation on The need of spacial data in geoscience and GeoCENS by Thomas Hoffman in Banff, September 23, 2010
The document discusses several topics related to environmental systems and human impacts: 1. It describes the nature of fluvial (river) systems and how they are variable over time and space from the watershed to habitat scale. 2. It discusses human impacts on sediment levels in the Rhine River catchment and the need for time-dependent spatial data on drivers like land use and responses like sediment flux. 3. Salmon populations are linked to river geomorphology, and there is a need for more data on this relationship to understand declines using tools like GeoCENS for visualization.
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Similar to GeoCENS presentation on The need of spacial data in geoscience and GeoCENS by Thomas Hoffman in Banff, September 23, 2010
GeoCENS presentation on The need of spacial data in geoscience and GeoCENS by Thomas Hoffman in Banff, September 23, 2010
- 1. Thomas Hoffmann Banff, Sep.18th 2010
- 2. Kananaskis River (RockyMnts.)
- 3. contents 1. Nature offluvial (environmental) systems 2. Human impact on sediment in the Rhine catchment – Scientific problem – Data needs GeoCENS 3. Salmon and geomorphology – Scientific problem – Data needs GeoCENS 4. Summary
- 4. contents 1. Nature offluvial (environmental) systems 2. Human impact on sediment in the Rhine catchment – Scientific problem – Data needs GeoCENS 3. Salmon and geomorphology – Scientific problem – Data needs GeoCENS 4. Summary
- 5.
- 6. time & space Environmentalsystems are systems that are: • variable in time and space • physical systems with a history • self organizing • hierarchical • response is dependent on spatial scale
- 7. time & space Environmentalsystems Timescales of adjustment of channel form component with given length dimension are systems that are: • variable in time and 107 Watershed 106 physiography space Valley Time (years) 105 • physical systems with 104 morphology, river profiles a history 103 Channel reach morphology, sediment • self organizing 102 routing, channel width and depth • hierarchical 101 Habitat unit morphology, grain • response is dependent 100 size, bedforms on spatial scale 101 102 103 104 105 106 107 108 109 Space (m²) modified after Montgomery (2004)
- 8. contents 1. Nature offluvial (environmental) systems 2. Human impact on the Rhine catchment – Scientific problem – Data needs GeoCENS 3. Salmon and geomorphology – Scientific problem – Data needs GeoCENS 4. Summary
- 9. problem: soil degradation • Globally, nearly 2 billion hectares of land are affected by human induced degradation of soils (UN, 2000) • Main driver of soil degradation: soil erosion • Old world: long human impact (several 1000 years) Grabenerosion auf einer gerade bestellten Rapsfläche long term perspective needed M. Firelinghaus
- 10. source to sink Floodplainsas proxies of environmental change Floodplains as major sinks Grabenerosion auf einer gerade bestellten Rapsfläche M. Firelinghaus Sources Fluss Regen in der Oberpfalz hat beim Augusthochwasser 2002
- 11. sedimentation rate [mm/yr] floodplain sedimentation Increase of mean SR since approx. 2000 BP strong human impact baseline SR: 0.5 mm/yr Hoffmann et al. (2009, Catena)
- 12. floodplain sedimentation Uniformincrease of mean sedimentation rate Increase of erosion Increase of human impact Problem: link between erosion and deposition rates? Hoffmann et al. (2009, Catena)
- 13. source to sink Floodplainsas proxies of environmental change Floodplains as major sinks Grabenerosion auf einer gerade bestellten Rapsfläche M. Firelinghaus Sources Fluss Regen in der Oberpfalz hat beim Augusthochwasser 2002
- 14. source to sink CoonCreek (Trimble 1999, Science) • Cause: Decreased soil erosion due to conservation measures • Affects: constant sediment delivery
- 15. source to sink connectivity Rhine catchment (Lang et al. 2003, Hydrological Processes) • Cause: Long human impact on hillslope erosion, with varying degree of deforestation • Affects: Buffered and delayed response of floodplains
- 16. what is needed? •Time dependent spatial information of external drivers – human impact • Location of agricultural areas at different scales: – large scale population distribution – small scale terrain position: slope/valley • Agricultural practice: – non plough, plough – size of agricultural fields – climate/hydrology • temperature • precipitation • discharge (magnitude & frequency) • Time dependent spatial information fluvial response – Sediment flux connectivity hillslope channel – Channel type + morphology (meandering/braiding)
- 17. land use historyin Germany Neolithic population (~7 ka BP) Roman population (~2ka BP) North Sea European Alps Zimmermann at el (2009)
- 18. what is needed? •Time dependent spatial information of external drivers – human impact • Location of agricultural areas at different scales: – large scale population distribution – small scale terrain position: slope/valley • Agricultural practice: – non plough, plough – size of agricultural fields – climate/hydrology • temperature • precipitation • discharge (magnitude & frequency) • Time dependent spatial information fluvial response – Sediment flux connectivity hillslope channel – Channel type + morphology (meandering/braiding)
- 19. human impact onthe Rhine before 1850 AD today
- 20. data types Vector Raster • Area: • Topography (DEMs) – land use • Climate data – geology – temperature – sediment storage location – precipitation • Line: time dependent – sediment transport paths (e.g. river network) – breaks of sediment transport (e.g. field edges) • Point: – Stratigraphical record (slope, floodplain) – Dating (e.g. 14C ages)
- 21. data types Vector Raster • Area: Necessary meta information! • Topography (DEMs) – land use • Time scale • Climate data – geology • Spatial representativeness – temperature – sediment storage location Upscaling of point data – precipitation • Line:Changing conditions! time dependent – e.g. changing land use in catchment of a gauging station sediment transport paths • Connectivitynetwork) points/objects extrapolation (e.g. river between – breaks of sediment transport • Quality evaluation!!! (e.g. field edges) • Point: – Stratigraphical record (slope, floodplain) – Dating (e.g. 14C ages)
- 22. GeoCENS application • TemporalGoogleEarth • Visualization of time dependent spatial data – Point data, line data and areal data e.g. visualization of changing land use (areal maps), 14C data of dated hillslope and fluvial sediment Time scales: ~10³ years From sensors to palaeo archives
- 23. Salmon & Geomorphology © http://www.thinksalmon.com
- 24. Fish habitat andgeomorphology Strong decline of salmon populations 60000 Chinook Coho Columbia River Commercial Landings Sockeye Chum 50000 Steelhead Total (in Thousands of Pounds) 40000 30000 20000 10000 0 1860 1880 1900 1920 1940 1960 1980 2000 years © http://www.thinksalmon.com Source: WDFW (2002)
- 25. the big four(five) H´s Harvest Habitat (overfishing) Salmon Hatcheries Hydropower (dams) History Assessment if restoration is possible © http://www.thinksalmon.com
- 26. salmon live cycleand habitats spawing: clean gravel of buried in appropriate size to spawn streambed + pools to rest shelter to grow, forage and hide from predators deep sheltered pools to rest ocean: food supply off channel wetlands + floodplains: summer rearing habitat and protection from winter floods Picture source: http://www.fishex.com/seafood/salmon/salmon life cycles.html
- 27.
- 28. changes of salmonhabitat Montgomery (2004) 1870 1990 Snohomish River (Washington) Snohomish River (Washington)
- 29. changes of salmonhabitat
- 30. changes of salmonhabitat Agricultural Deforestation Urbanization land use loss large woody high input of fine loss of wetlands & debris input into sediments into floodplains channels channel decreasing hetero siltation of geneity of channel bed channel beds morphology Loss of salmon habitat
- 31. restoration Understanding of: – Watershed processes (not only channel) • Water, sediment and large wooded debris flux – Hillslope channel connectivity – Transport within channel • Coupling of system components and processes – Coupling between processes and channel morphology – Coupling between biology and geomorphology/hydrology Spatial context – Disturbance history • Land use history • Channel morphology today and before human impact Temporal context
- 32. which data needed? • High resolution digital elevation models (DEMs) (esp. LIDAR = Light Detection + Ranging) – Extraction of channel networks – Mapping of geomorphological landforms identification of sediment transport processes – Classification of channel morphology Hillshade of LIDAR DEM (1m resolution) – Reconstruction of former Kananaskis country channel courses • Aerial photographs – Mapping of changing channel pattern – Reconstruction of land use history – Identification of sediment sources and storages
- 33. which data needed? step pool casacade plane Hillshade of LIDAR DEM (1m resolution) bed Kananaskis country Pool riffle pool riffle plane bed step pool cascade Classification based on Montgomery & Buffington (1997), data source 5m DEM (rescaled 1m LIDAR DEM)
- 34. which data needed? •Sediment size = most hs D50 * * important channel ( s )g c ( s ) c characteristic for spawning • Availability of suitable sediment dependent on: – Channel hydraulics (shear stress) – Sediment supply (volume and grain size) Estimation of sediment size based on DEM derived plane bed channels channel slope and wood poor pool riffle channels wood forced pool riffle channels drainage area increasing roughness / resistance
- 35. which data needed? • High resolution digital elevation models (DEMs) (esp. LIDAR = Light Detection + Ranging) – Extraction of channel networks – Mapping of geomorphological landforms identification of sediment transport processes – Classification of channel morphology – Reconstruction of former channel courses • Aerial photographs – Mapping of changing channel pattern – Reconstruction of land use history – Identification of sediment sources and storages. Orthophoto, 1m resolution (2008)
- 36.
- 37. summary Restoration of salmonhabitat only possible if we have a good understanding of: • ecological and geomorphological processes in salmon bearing rivers • how these rivers evolved in time
- 38. GeoCENS application • TemporalGoogleEarth • Visualization of time dependent spatial data – Point data, line data and areal data e.g. visualization of changing land use (areal maps), changing river habitat (linear features) and salmon populations Time scale: 10² years (since air photos are available)
- 39. take home message geospatial data is not just xyzt but information in a geographical context
- 40. take home message •If we want a large geoscientific community to use GeoCENS we need to integrate spatial and temporal, e.g.: – Geological, geomorphological maps – Digital elevation models – Time dependent land use maps – ……and derivatives • However: quality concerns must be met • Visualization tool of spatial temporal data important for every paleo environmental study
- 41.