EGU General Assembly 2014
May 2nd, 2014, Vienna
Using the TRIGRS Model to
Predict Rainfall-Induced
Shallow Landslides Over
Large Areas
Gioia, E.1, Speranza, G.2, Ferretti, M.2, Marincioni, F. 1,
Godt, J. W.3, and Baum, R. L.3
(1) Department of Life and Environmental Sciences, Marche Polytechnic University, Via
BrecceBianche, Ancona, 60100, Italy, e.gioia@univpm.it;
(2) Regional Forecast Center, Marche Region, Via del ColleAmeno 5, Ancona, 60126, Italy;
(3) U.S. Geological Survey, Box 25046 MS 966, Denver, CO 80225-0046
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1. Introduction
(pictures
courtesy of the
Marche Civil
Protection)
99% municipalities affected
91%
9%
Landslides
Floods
(Ministry for the Environment, Land and Sea - Report 2008)
USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
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1. Introduction
FORECAST
PREVENTION
WARNING
SYSTEM
EVENT
EMERGENCY
MANAGMENT
RECOVERY AND
RESTORATION
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
1. Introduction
LANDSLIDES FORECAST
EMPIRICAL
MODELS
(STATISTICAL)
PHYSICAL
MODELS
(DETERMINISTIC)
•Antecedent rainfall (A) ;
• Rainfall intensity (I) ;
• Rainfall duration (D) :
• Probability
• Hydrological features;
• Hydrogeological features;
• Geomorphological features;
• Geotechnical features;
• Structural features.
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
1. Introduction
TRIGRS
(Transient Rainfall Infiltration and Grid-based Regional Slope Stability)
RANGE
c [kPa]
c≥0
φ [deg]
φ>0
ϒs [N m-3]
ϒs > 0
D0 [m2 s-1] D0 > zmin
Ks [m s-1]
Ks > 0
θr [-]
θs > θr ≥ 0
θs [-]
θs > 0
α [m-1]
α>0
𝒓𝒆𝒔𝒊𝒔𝒕𝒊𝒏𝒈 𝒇𝒐𝒓𝒄𝒆𝒔
𝑭𝒔 =
𝒅𝒓𝒊𝒗𝒊𝒏𝒈 𝒇𝒐𝒓𝒄𝒆𝒔
USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
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2. Study area
THE POST-OROGENIC COMPLEX OF THE ESINO RIVER BASIN
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
3. Data collection
LANDSLIDES (82) OCCURRED DURING THE PERIOD 1990-2012
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
3. Data collection
RAIN GAUGES USED FOR THE STUDY
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
3. Data collection
LANDSLIDES TEXTURE CLASSES
LANDSLIDE FREQUENCY
44
29
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CLAY
SANDY-CLAY
LOAM
3
GRAVEL
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
3. Data collection
BOX PLOT CHARTS OF CENTRAL TENDENCIES
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
4. Method
SETTINGS
STEP 1: TRIGRS calibration
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
4. Method
SETTINGS
STEP 1: TRIGRS calibration
STEP 2: Outline test cases, choose the rainfall event, select the rain gauge and the rainfall
intervals
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
4. Method
SETTINGS
STEP 1: TRIGRS calibration
STEP 2: Outline test cases, choose the rainfall event, select the rain gauge and the rainfall
intervals
STEP 3: Evaluate an “Antecedent Water Index”
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
4. Method
SETTINGS
STEP 1: TRIGRS calibration
STEP 2: Outline test cases, choose the rainfall event, select the rain gauge and the rainfall
intervals
STEP 3: Evaluate an “Antecedent Water Index”
STEP 4: Construct input grids of slope from a 20m DEM, property zones, rainfall input,
soil depth and water table depth
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
5. Results
OCTOBER 1996 CASE STUDY
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
5. Results
RECEIVER OPERATING CHARACTERISTICS (ROC) ANALYSIS
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
6. Conclusion
We presented an innovative methodology for the application of a
physical model (TRIGRS) for rainfall-induced shallow landslides
forecasting over broad areas.
 TRIGRS well predicts the instabilities, thus can be used to build an
accurate susceptibility map;
 Rainfall-induced landslides over large regions may be predicted
even where geotechnical and hydraulic properties data as well as
temporal changes in topography or subsurface conditions are not
available.
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USING THE TRIGRS MODEL TO PREDICT RAINFALL-INDUCED SHALLOW LANDSLIDES OVER LARGE AREAS
… Thank you
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