The rainfall intensity-duration control of shallow landslides and debris flows : an update Guzzetti, F., Peruccacci, S., Rossi, M., and Stark, C.
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Slide 1
The rainfall intensity-duration control of
shallow landslides and debris flows : an update
Guzzetti, F., Peruccacci, S., Rossi, M., and Stark, C. P., 2008. The rainfall intensity-duration
control of shallow landslides and debris flows: an update. Landslides, 5(1), 3-17.
指導教授：李錫堤 教授
學生：邱奕勛
報告日期：100.6.16
1
Slide 2
Outline
Introduction
Rainfall and landslide information
Rainfall intensity–duration data
Objective identification of rainfall thresholds
Global rainfall ID thresholds
Conclusions
2
Slide 3
Introduction (1/3)
In 1980, Nel Caine published a paper entitled “The rainfall intensity–
duration control of shallow landslides and debris flows”.
I 14.82 D
0.39
(0.167 D 500)
I：rainfall intensity in millimeter per hour (mm/h)
D：rainfall duration in hours (h)
3
Slide 4
Introduction (2/3)
Rainfall ID thresholds are used to forecast the occurrence of
shallow landslides and debris flows based on continuous rainfall
measurements.
To account for climatic effects, the rainfall intensity is normalized
by the mean annual precipitation (MAP) and the rainy-day
normal (RDN ,Wilson and Jayko 1997).
Rainfall thresholds can be defined physically or empirically.
Regional thresholds and Local thresholds.
4
Slide 5
Introduction (3/3)
Rainfall and climate variables used in the literature for the definition of rainfall thresholds for the initiation of landslides
5
Slide 6
Rainfall and landslide information (1/6)
The collected information was organized in a catalogue
listing 2,626 landslide events covering the 89-year period
between 1917 and 2005.
areas for which rainfall characteristics resulting in shallow landslides
6
Slide 7
Rainfall and landslide information (2/6)
Geographical precision for the
location of the rainfall and
landslide events.
Proportion of landslide events
for which antecedent rainfall
information is available.
7
Slide 8
Rainfall and landslide information (3/6)
Proportion of different shallow
Landslide types.
Number of reported landslides
for each rainfall event.
8
Slide 9
Rainfall and landslide information (4/6)
Accuracy of the temporal
information.
Information on the exact
or approximate time, date
, or period of failure.
Information on lithology.
9
Slide 10
Rainfall and landslide information (5/6)
Climate classification, based on
the Köppen climate classification
system.
10
Slide 11
Rainfall and landslide information (6/6)
Frequency of rainfall events for classes
of mean annual precipitation (MAP).
Frequency of rainfall events for classes
of average number of rain days (RDs)
11
Slide 12
Rainfall intensity–duration data (1/3)
moving-average filtering
Raw ID data.
48 hr
Percentile estimates of rainfall ID
conditions.
12
Slide 13
Rainfall intensity–duration data (2/3)
48 hr
Normalized rainfall
intensity-duration
conditions (MAP).
Normalized rainfall
intensity-duration
conditions(RDN).
13
Slide 14
Rainfall intensity–duration data (3/3)
Climate information for the 15 climate regions considered in this work.
14
Slide 15
Objective identification of rainfall
thresholds (1/1)
In general, a rainfall threshold is drawn visually as the (apparent) lower
boundary for the rainfall conditions.
New method
A. threshold curve of the form I D was selected to describe
the threshold.
B. Bernoulli probability approach was used to find the scale (intercept) α
and the shape (slope) β of the power law curve.
P ( I , D )~ dbern [( ( I , D )] , 0 P 1
( I , D ) {(1 ) [ z ( I , D )] } exp[ z ( I , D ) ]
w here z ( I , D ) 1 D
/ I.
set to 0.1 and 0.5
1 / ~ dunif (0.001,10)
~ dunif [0.1, 2]
15
Slide 16
Global rainfall ID thresholds (1/4)
MAP
Global rainfall ID thresholds
for the initiation of shallow
landslides and debris flows.
Raw data
RDN
0.25 mm/hr
17
Slide 17
Global rainfall ID thresholds (2/4)
Raw
data
Validation of obtained ID
and normalized-ID rainfall
thresholds.
MAP
RDN
18
Slide 18
Global rainfall ID thresholds (3/4)
Comparison with existing global thresholds
1. Caine (1980)
2 .Innes (1983)
3 .Clarizia et al. (1996)
4. Crosta and Frattini (2001)
5. Cannon and Gartner (2005)
6.Threshold inferred from
the entire set of ID rainfall
data (this work)
7. Thresholds for two
different rainfall periods
(D < 48 h, and D ≥ 48 h)
(this work)
19
Slide 19
Global rainfall ID thresholds (4/4)
24hr
80hr
Climatically subdivided
thresholds
20
Slide 20
Conclusions (1/1)
New statistical treated outliers in an unbiased way and reduced
interpretation errors.
Collection of a large number of ID rainfall data through a literature
search.
Results of the normalization indicate that MAP and RDN did not
reduce significantly.
A global landslide warning system could contribute to mitigate
landslide risk.
21
Slide 21
Thank for your attention
22
The rainfall intensity-duration control of
shallow landslides and debris flows : an update
Guzzetti, F., Peruccacci, S., Rossi, M., and Stark, C. P., 2008. The rainfall intensity-duration
control of shallow landslides and debris flows: an update. Landslides, 5(1), 3-17.
指導教授：李錫堤 教授
學生：邱奕勛
報告日期：100.6.16
1
Slide 2
Outline
Introduction
Rainfall and landslide information
Rainfall intensity–duration data
Objective identification of rainfall thresholds
Global rainfall ID thresholds
Conclusions
2
Slide 3
Introduction (1/3)
In 1980, Nel Caine published a paper entitled “The rainfall intensity–
duration control of shallow landslides and debris flows”.
I 14.82 D
0.39
(0.167 D 500)
I：rainfall intensity in millimeter per hour (mm/h)
D：rainfall duration in hours (h)
3
Slide 4
Introduction (2/3)
Rainfall ID thresholds are used to forecast the occurrence of
shallow landslides and debris flows based on continuous rainfall
measurements.
To account for climatic effects, the rainfall intensity is normalized
by the mean annual precipitation (MAP) and the rainy-day
normal (RDN ,Wilson and Jayko 1997).
Rainfall thresholds can be defined physically or empirically.
Regional thresholds and Local thresholds.
4
Slide 5
Introduction (3/3)
Rainfall and climate variables used in the literature for the definition of rainfall thresholds for the initiation of landslides
5
Slide 6
Rainfall and landslide information (1/6)
The collected information was organized in a catalogue
listing 2,626 landslide events covering the 89-year period
between 1917 and 2005.
areas for which rainfall characteristics resulting in shallow landslides
6
Slide 7
Rainfall and landslide information (2/6)
Geographical precision for the
location of the rainfall and
landslide events.
Proportion of landslide events
for which antecedent rainfall
information is available.
7
Slide 8
Rainfall and landslide information (3/6)
Proportion of different shallow
Landslide types.
Number of reported landslides
for each rainfall event.
8
Slide 9
Rainfall and landslide information (4/6)
Accuracy of the temporal
information.
Information on the exact
or approximate time, date
, or period of failure.
Information on lithology.
9
Slide 10
Rainfall and landslide information (5/6)
Climate classification, based on
the Köppen climate classification
system.
10
Slide 11
Rainfall and landslide information (6/6)
Frequency of rainfall events for classes
of mean annual precipitation (MAP).
Frequency of rainfall events for classes
of average number of rain days (RDs)
11
Slide 12
Rainfall intensity–duration data (1/3)
moving-average filtering
Raw ID data.
48 hr
Percentile estimates of rainfall ID
conditions.
12
Slide 13
Rainfall intensity–duration data (2/3)
48 hr
Normalized rainfall
intensity-duration
conditions (MAP).
Normalized rainfall
intensity-duration
conditions(RDN).
13
Slide 14
Rainfall intensity–duration data (3/3)
Climate information for the 15 climate regions considered in this work.
14
Slide 15
Objective identification of rainfall
thresholds (1/1)
In general, a rainfall threshold is drawn visually as the (apparent) lower
boundary for the rainfall conditions.
New method
A. threshold curve of the form I D was selected to describe
the threshold.
B. Bernoulli probability approach was used to find the scale (intercept) α
and the shape (slope) β of the power law curve.
P ( I , D )~ dbern [( ( I , D )] , 0 P 1
( I , D ) {(1 ) [ z ( I , D )] } exp[ z ( I , D ) ]
w here z ( I , D ) 1 D
/ I.
set to 0.1 and 0.5
1 / ~ dunif (0.001,10)
~ dunif [0.1, 2]
15
Slide 16
Global rainfall ID thresholds (1/4)
MAP
Global rainfall ID thresholds
for the initiation of shallow
landslides and debris flows.
Raw data
RDN
0.25 mm/hr
17
Slide 17
Global rainfall ID thresholds (2/4)
Raw
data
Validation of obtained ID
and normalized-ID rainfall
thresholds.
MAP
RDN
18
Slide 18
Global rainfall ID thresholds (3/4)
Comparison with existing global thresholds
1. Caine (1980)
2 .Innes (1983)
3 .Clarizia et al. (1996)
4. Crosta and Frattini (2001)
5. Cannon and Gartner (2005)
6.Threshold inferred from
the entire set of ID rainfall
data (this work)
7. Thresholds for two
different rainfall periods
(D < 48 h, and D ≥ 48 h)
(this work)
19
Slide 19
Global rainfall ID thresholds (4/4)
24hr
80hr
Climatically subdivided
thresholds
20
Slide 20
Conclusions (1/1)
New statistical treated outliers in an unbiased way and reduced
interpretation errors.
Collection of a large number of ID rainfall data through a literature
search.
Results of the normalization indicate that MAP and RDN did not
reduce significantly.
A global landslide warning system could contribute to mitigate
landslide risk.
21
Slide 21
Thank for your attention
22