Lecture Overview - · PDF file1 1 Lecture Overview Definition: geomorphology Geomorphic...

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Lecture Overview

Definition: geomorphologyGeomorphic mappingReview: Landslide terminology & classification systemsCharacteristics of landslidesMapping of landslide typesExamples of geomorphic mapping in landslide studies

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Linkages

Form

Material

Process

Geomorphology is the science of relief forms, forming materials and the changing processes.

Rotmoostal /Gurgler Tal

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Iceland - Photopraphs

Aerial photography of Bíldudalur, viewto North

Bíldudalur,Westfjords

(Photo: Matz Wibelund)

Glade & Jensen 2002

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Geomorphological map

Glade & Jensen (2004)

Geomorphic mapping

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Sediment origin

Soil creep / solifluction

Appl. Model

Assumption: 25mm/yr with 0.5m

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Example: Geomorphic mapping in the Turtmannvalley, Switzerland

Otto

& D

ikau

, 200

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Thematic components of the geomorphologic map of the Turtmann valley

Otto

& D

ikau

, 200

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Field observationHatched polygonsNot specifiedSubsurface Material

Field observation,topographic maps

Line symbols and polygons

Not specifiedHydrology/Glaciology

Field observation,process recognition,material properties, inferring of past processes based on landform geometry and material.

Coloured polygonsAll scales (active and past processes)

Process Domain

Field observation, analysis of DTM and topographic maps

Line symbolsNot specifiedGeomorphography(steps and breaks of slope, valleys and drainage ways)

Field observationLine or point symbolsPartly specifiedSingular Landform

Field observation,state of activity according to indicators (see text)

Point symbols (red or black)

Activity 1 in the last 5 years (red)No Activity in the last 5 years (black)

GeomorphologicProcess

Information sourceMap legend symbolTemporal scaleThematic layers

1Types of activity: continuous, intermittent, episodic, singular

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Qualitative sediment flux model of the Brändjitälli hanging valley

Otto

& D

ikau

, 200

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Otto & Dikau, 2004

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Otto & Dikau, 2004

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Otto & Dikau, 2004

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Otto & Dikau, 2004

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Otto & Dikau, 2004

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Otto & Dikau, 2004

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Otto & Dikau, 2004

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Example: Sediment storage - Rain valley, Germany

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Linking storage – process / Activity of storages

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Geomorphic mapping in landslide studies

Mös

sing

en-Ö

schi

ngen

GMK 25Leser 1972

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Landslide terminologyCrownMain scarpTopHeadMinor scarpMain BodyFootTipToe

Surface of ruptureSurface of separationZone of depletion

Zone of accumulationDepletionDepleted massAccumulationFlank

Adopted from Cruden & Varnes, 1996

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Landslide classifications

Material: Rock, Soil, Lithology, structure, Geotechnical properties

Geomorphic attributes: Weathering, Slope formLandslide geometry: Depth, Length, Height etc.Type of movement: Fall, Slide, Flow etc.Climate: Tropical, Periglacial etc.Water: Dry, wet, saturatedSpeed of movement: Very slow, slow etc.Triggering mechanism: Earthquake, rainfall, etc.

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Landslide classifications (1/3) – Sharpe 1938

Material: earth, rockMovement: flow, slipVelocity: slow to very rapidWater/ice content

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Landslide classifications (2/3) – Varnes 1978

Material: bedrock, debris, earthMovement: fall, topple, slide, flow, complexSecondary: water content, velocity

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Landslide classifications (3/3) – Wieczorek 1984

YESF:Y = Dormant-YoungE = EarthS = SlideF = Flow

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Landslide characteristics: Morphology

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Landslide characteristics: Vegetation

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Landslide characteristics: Drainage

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Landslide characteristics: Active vs. Non-active

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Mapping Landslide Types

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Mapping Landslide Types

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Field methods – topographic measurements Tachymeter

Petrahn 1996

Petrahn 1996

Großmann 1983

Keaton & de Graff1996

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Field methods – topographic measurements Tachymeter

Petrhn 1996

Keaton & de Graff 1996

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Natural Hazards/Risk & Geomorphology

Geomorphologic mappingIdentification of distributions of processesEstimation of temporal occurrenceAnalysis of materialAssessment of sediment storageBasic information for process modeling

Geomorphologic process studiesVerification of assumptionsEstimation of sediment production

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Mapping

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GPS

Demoulin & Glade 2004

Period: Okt 01 – Mai 02Okt-Dez: no movementJan: 3cm – snow meltingFeb: ~30cm – heavy rainfallsMarch: no movement

Field methods – topographic measurements

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Geomorphic mapping

Legend of Terhorst (2001)

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Geomorphic mapping

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Geomorphic mapping

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General geomorphological Mapping with focus on landslides1:50,000(Kallinich 1999)

Only cuesta and landslide heads were mapped


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Geomorphic mapping in landslide studiesM

össi

ngen

-Ösc

hing

en

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Geological profile derivedfrom geomorphologicalmapping

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össi

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-Ösc

hing

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Mös

sing

en-Ö

schi

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össi

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-Ösc

hing

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Elements at risks - Houses

Mös

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ngen

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Elements at risk – Classified regionsM

össi

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Elements at risk – Classified regions

Mös

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Mapping of Rockfall impact – (1/2)

Wieczoreck et al. (2000)

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Mapping of Rockfall impact – (2/2)

Wieczoreck et al. (2000)

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ConclusionForm – Geomorphometric features• Approximation of age• Topographic measurements (Tachymeter, GPS)

Material – Near subsurface material• 1m drillings

Process domains• Dominant process – spatially distributed• Grade of activity

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ReferencesCruden, D.M. and Varnes, D.J. 1996: Landslide types and processes. In Turner, A.K. and Schuster, R.L., editors, Landslides: investigation and mitigation,Washington, D.C.: National Academey Press, 36-75.Demoulin, A. and Glade, T. in prep.: Recent landslide activity in Manaihan, Belgium. Landslides.Glade, T. and Jensen, E.H. 2004: Landslide hazard assessments for Bolungarvíkand Vesturbyggð, NW-Iceland. Reykjavik: Icelandic Meteorological Office.Glade, T., Kadereit, A. and Dikau, R. 2001: Landslides at the Tertiary escarpement of Rheinhessen, Southwest Germany. Zeitschrift fürGeomorphologie, Supplement Band 125, 65-92.Kallinich, J. 1999: Verbreitung, Alter und geomorphologische Ursachen von Massenverlagerungen an der Schwäbischen Alb auf der Grundlage von Detail-und Übersichtskartierungen.Knödel, K., Krummel, H. and Lange, G., editors 1997: Geophysik. Berlin: Springer Verlag.Reynolds, J.M. 1997: An Introduction to Applied and Environmental Geophysics. Chichester, UK: John Wiley & Sons.

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ReferencesSharpe, C.F.S. 1938: Landslides and Related Features - A Study of Mass Movements of Soil and Rock. New York. pp. 137.Selby, M.J. 1993: Hillslope materials and processes. Oxford: Oxford University Press.Otto, J.-C. and Dikau, R. 2004: Geomorphic system analysis of a high mountain valley in the Swiss Alps. Zeitschrift für Geomorphologie N.F. 48, 323-341.Terhorst, B. and Kirschhausen, D. 2001: Legends for mass movements in the MABIS-Project. Zeitschrift für Geomorphologie, Supplement Band 125, 177-192.Varnes, D.J. 1978: Types of slope movement.Wieczorek, G.F. 1984: Preparing a Detailed Landslide-Inventory Map for Hazard Evaluation and Reduction. Bulletin of the Association of Engineering Geologists21, 337-342.Wieczorek, G.F., Snyder, J.B., Waitt, R.B., Morissey, M.M., Uhrhammer, R.A., Harp, E.L., Norris, R.D., Bursik, M.I. and Finewood, L.G. 2000: Unusual July 10, 1996, rock fall at Happy Isles, Yosemite National Park, California. GSA Bulletin no.1, 75-85.

Lecture Overview - · PDF file1 1 Lecture Overview Definition: geomorphology Geomorphic...

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