Ability of the GIS to incorporate the spatially varying data of ground elevation, soil properties, slope, etc. in the engineering analysis of the slope stability. gis

1. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
M.Sc. GIS Program – GEOG 587 class
Presented by: Edmundo M. Zevallos
April 3rd. 2011

2. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
 A Landslide is a Mass movements under influences of gravity.
 Occurs as a result of diverse disturbing and destabilizing
Introduction processes, for example of climatic or anthropological origin.
 The stability of slopes is determined by the geometry of surfaces
and slip-horizons.
p
In regard to spatial landslide analysis, GIS is an important tool to carry out data input,
handling, visualization, combination, query, analysis.
Ability of the GIS to incorporate the spatially varying data of
Hypothesis: ground elevation, soil properties, slope, etc. in the engineering
analysis of the slope stability.

3. GIS LANDSLIDES ANALYSIS
USC MARINE CAMPUS-TWO HARBORS
Roadway between USC Wrigley Institute and Two Harbors
ROADWAY Catalina Island, CA.
• An analysis of landslide in an specific area of the Catalina Island.
• Study Area located in the north west part (section, third) of the island.
(section island
• In the East-West existing roadway between the USC Wrigley Institute facility and the
town of Two Harbors.
Research following a
spatially-distributed data with
a geo-reference to real world.
USC Wrigley Institute
Existing
Roadway
Area of
y
Analysis
Two Harbors

4. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
 Raster-based GIS was applied in order to analyze the spatial
distribution of landslides.
landslides
 Parameters established in a map: 1.- slope
2.- Geology
3.- Geomorphology
4.- drainage/scour network
5.- Road network
Abstract  Four possible landslides spot were inventoried in the study.
 Followed by a field work inventory in the North East side of the
existing roadway.
 Three types of landslides were identified in the study area
1.- scour
2.- rock falls
3.- flows
 The landslides are distributed:
1.-
1 on a wide range of slope (15% t 50%) gradient ( f 1)
id f l to di t (ref.1)
2.- Two constant geological (ref 2) setting: - Catalina Schist
- Volcanic.
 This paper will demonstrates the ability of the GIS to incorporate
the spatially varying data of: - ground elevation, soil properties, etc.
p y y g g , p p ,
in the engineering analysis of the slope stability.

5. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
The management of spatial-data is pivotal for this analysis, due:
1. - The unique capability of GIS: to work
To capture
To store
GIS and
Landslide Manage the data
analysis 2. - The handle of data referenced: by vast spatial
Or
O geographic coordinates
hi di t
3. - Its ability to incorporate appropriate engineering models
In the case of the landslide analysis in here, this analysis demands:
1. - Collection of data,
2. - Storage of data
3.
3 - Use of the data for the analysis handled in the GIS
environment.

6. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.

7. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
GPS device Reported Number of Description
accuracy points taken of points
Nomad 5 mt 5 points Drainage
(Trimble) Structures and
Collection
Possible Slide
of data
land location
630 point
GPS devices were GPS Setup to
used and their logging
results different interval every
accuracy. 5 seconds
2,120 points
GPS setup to
logging
interval every
1 meter
Geo XH 45 cm 18 points
(
(Trimble)
)

8. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
Storage of data and processing
ArcMap Layers:
ArcMap storage of Data and analysis
g y
spatially-distributed data and
geo-reference to real world.
Critical area
along road
Typical Drainage structure
+
Typical possible Landslide spot

9. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
GPS Pathfinder Office
Creation of Data Dictionary editor
Data Collector
device
ArcMap storage of Data
and spatial analysis
Storage of data
and processing
(cont.)
Thickness
Sratigraphy thickness Slope
4,521 polygons
US Geological Survey
Metadata of Catalina Island

10. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
Formulation of Typical landslide analysis
F l ti f T i l l d lid l i
 A slope stability analysis combined with risk
analyses is proposed to carry out.
 The area under investigation is geoprocessed in
ArcMap, and marked with more than 4,000 point
elevations.
elevations
 It could observe that the hill is sloping downward
towards northwest.
 The slide has occurred at the upper regions.
 Various man-made features are also present, like
roads and only three drainage structures, a
stream f lli in the d
t falling i th downslope.
l

11. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
Formulation of Typical
landslide analysis (cont.)
 The steps involved in the
landslide hazard it
generates a mapping
given as flow chart.
 The formulation of the
work is described.
 The methodologygy
proposed would be able to
develop the hazard map,
and perform decision
analysis

12. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
Colored
Contours Triangles
Triangles DTM
surfaces
Digital
Terrain
Model
Plan View of Existing Road
Profile of Existing Road

13. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
Conclusions
1) I studied the distribution / characterization of landslides in the study area through:
- Photointerpretation
- Geomorphologic survey
2) This area of study is characterized by two stratigraphic-structural units:
- Mostly Miocene volcanic rocks
- Tertiary subvolcanic rocks
3) This research shows that in the area of the analysis there are two types of landslides:
- slow earth flow their landslide masses are quite small
- rock f ll  occur i limestone formations
k falls in li t f ti
4) Morphometric characteristics, play an important role in landsliding processes.
5) Can be determined through the analysis of the digital terrain model.

14. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
Conclusions (cont.)
6) The application of this method would be useful to locate potential unstable areas,
and so to predict the occurrence of future landslides.
7) Since the slides has occurred at the upper regions and hence short-term
remediation will be an immediate solution in the form of relief wells.
8) The analysis using:
- Hydrologic models could be incorporated in the Arc View
- Stability models
9) GIS-based techniques are the best approach to the study of landslide
susceptibility because they allow the management of several themes concerning
tibilit b th ll th t f l th i
instability factors.
10) Geographic Information Systems (GIS) is being exploited widely in many
engineering problems which involves spatial data management
problems, management.

15. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
Thank you for your attention
Any questions?

16. GIS LANDSLIDES ANALYSIS
Roadway between USC Wrigley Institute and Two Harbors
Catalina Island, CA.
References
 Soil Survey of Catalina Island, California. USDA (2008)
 USGS - Soils data for the Conterminous United States
Derived from the NRCS State Soil Geographic (STATSGO)
Data Base. (2001)
D t B
 Landslide analysis in Geographic Information Systems, G.L.
Babu (1998)
 Soils data for the Conterminous United States Derived from
the NRCS State Soil Geographic (STATSGO) Data Base.
(1995) USGS.