2. Landslide Hazard Modeling
Table of Contents
1. Chapter 01
04
a. Introduction to Hazard
04
b. Types of Hazards
04
c. Hazard Identification
04
d. Hazard Modeling
05
i. Steps for Hazard Modeling
05
ii. Reasons for Hazard Modeling
05
2. Chapter 02
07
a. Objective
07
b. Study Area
07
c. Data Sources
07
d. Data Format
07
e. Software
07
f. Methodology
07
g. Results
08
h. Comparisons
13
3. Issues and Problems
16
4. Conclusions
17
5. Reference
18
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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3. Landslide Hazard Modeling
Figures List
Figure 1: Steps to conduct Hazard Modeling
06
Figure 2: Shape file of Dewal_2008
09
Figure 3: Shape file of Dewal_2012
09
Figure 4: Raster of Dewal_2008
10
Figure 5: Raster of Dewal_2012
10
Figure 6: Profile Graph_2008
11
Figure 7: Profile Graph_2012
11
Figure 8: Results in Arc GIS
12
Figure 9: Results in Auto-cad
13
Figure 9: Shape files Comparison
14
Figure 10: Raster Comparison
15
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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4. Landslide Hazard Modeling
Chapter 01
Bbefore dealing with hazard modeling, firstly understand the true meaning of hazard. What is
actually a hazard is?
Hazard is defined as:
“A hazard is a source of potential danger or adverse conditions.”
Types of Hazards
The type of hazard has been classified into two major categories:
1. Natural
2. Man Made
Natural Hazards:
It includes:
Floods,
Hurricane,
Earthquake,
Tornadoes,
Wildfires,
Landslides.
Viruses,
Weapons of mass destructions,
Chemical
Explosions,
Chemical and biological agent,
Terrorism.
Man Made Hazards:
It includes:
split,
Hazard Identification
The most important task in hazard modeling is to identify the areas that are:
1. The sources of hazards, and
2. More affected by the hazards.
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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5. Landslide Hazard Modeling
According to FEMA (Federal Emergency Management Agency),
“Hazard identification is a process of defining and describing a hazard, including its physical
characteristics, magnitude and severity, probability and frequency, causative
factors,
and
locations/areas affected.”
(Schwab et al. 1998)
Consider the Effects of Hazard Before Disaster Happens
It is important to keep eye on the cause of hazards before the disaster happens from previously
tracked or recorded data. The most meaningful steps are taken by the state and local level
officials that have a personal contact with the community.
1. It cost too much to address the effects after the disaster,
2. One can prevent some of the damage from hazard if one knows where and how the
natural phenomenon occurs,
3. Most probably federal aid after disaster does not cover all portions and costs effectively.
Hazard Modeling
During hazard modeling, one uses the current knowledge and pre-existing structures to identify
the areas that are prone to disasters. In additions to that, the community growth plan or flat map
super imposed with the hazard map will help us to identify the areas that are more vulnerable to
natural hazards.
Steps to Conduct Hazard Analysis:
Few of the steps are mentioned below used to conduct the hazard analysis:
1. Analyze each potential event from beginning to end.
2. Estimate the probability of the events occurring.
3. Analyze potential human effect on each disaster. (e.g. death or injury)
4. Assess the potential property impact on losses and damages.
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Institute of Geology (Session: 2013-15)
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6. Landslide Hazard Modeling
Fig 1: Steps to conduct Hazard Modeling
Reasons for Hazard Analysis:
The few of the reasons for hazard analysis are as follows:
1. Identify the areas that are most at risk,
2. Identify the risks for built/ natural environment,
3. Assess capability to response/recover,
4. Provide data for economic analysis,
5. Provide base for decisions,
6. Helps to apply cost-benefit approach.
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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7. Landslide Hazard Modeling
Chapter 02
Objective
The objective is to find out the areas that are more susceptible to hazards due to its topological
structure.
By making comparison of data of different times, we can estimate the cut/fill area.
Study Area
The study area is Dewal, Murree, Pakistan located at 33°59'0N, 73°28'0E with an altitude of
1712 meters and UTM zone 43N. It is a Union Council of Murree Tehsil (a sub division), of
Rawalpindi District in the Punjab province of Pakistan.
Data Sources
The data is acquired by the help of the total stations.
Data Format
The data is in Excel format with elevation values of Dewal side of the year 2008 and 2012.
Software
The software used is:
1. Arc GIS 9.3
2. Auto cad 2007 & 2010
Methodology
The performed step by step procedure is as follows:
STEP: 01
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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8. Landslide Hazard Modeling
1. Open Arc Map 9.3.
2. Add Excel File.
3. Display XY Data.
4. Export the shape file.
5. Create a shape file of Polygon. And edit the boundary of the exported Points shape file.
6. Create Raster:
a. Spatial Analyst Tool – Interpolation – Topo to Raster
b. Add Shape file of points and polygon.
c. For Point Shape file: Use “Point Elevation” and “ZC” under filed tab.
d. For Polygon Shape file: Use “Boundary” under filed tab.
e. Use “No Contour” under the field of Drainage.
f. Click OK.
7. By using 3D Analyst: pick “Interpolate Line” and draw a line over the raster.
8. By using 3D Analyst: pick “Profile Graph” and calculate the Vertical Profile.
9. By Right clicking the graph, Export the graph to Data type Excel.
10. Repeat the procedure for both year data.
11. Create Map Layout for each data.
STEP: 02
1. Open Auto cad.
2. In Command Line, type: “pl” and Enter.
3. From the Exported Excel file of Profile Graph, Copy the XY data and Paste in the
Command line, and press Enter.
4. Press Esc to cancel.
5. Decorate the graph for Save and Display.
Results
The results are shown in the form of Maps as follows:
1. Exported shape file of year 2008.
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Institute of Geology (Session: 2013-15)
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9. Landslide Hazard Modeling
Fig 2: Shapfile_2008
2. Exported shape file of year 2012.
Fig 3: Shapefile_2012
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Institute of Geology (Session: 2013-15)
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10. Landslide Hazard Modeling
3. Raster date of year 2008.
Fig 4: Raster Data_2008
4. Raster data of year 2012. (Fig 5: Raster Data_2012)
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Institute of Geology (Session: 2013-15)
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11. Landslide Hazard Modeling
5. By using Profile Graph, calculate the Vertical Profile of the Dewal area of year 2008.
Fig 6: Vertical Profile_2008
6. By using Profile Graph, calculate the Vertical Profile of the Dewal area of year 2012.
Fig 7: Vertical Profile_2012
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Institute of Geology (Session: 2013-15)
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12. Landslide Hazard Modeling
7. The final output of cut/fill result in the arc GIS is as follows: (Fig 8: Results in Arc GIS)
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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13. Landslide Hazard Modeling
8. And the same output in the Auto-cad is as follows: (Fig 9: Results in Cad)
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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14. Landslide Hazard Modeling
Comparisons
By comparing the results, it is clear that overall elevation increases from the year 2008 to 2012.
Following comparison map is showing the area of Dewal and surveyed points for the year 2008
and 2012, up and down, respectively. (Fig 10: Shape files Comparison)
In the survey of 2012, two prominent points have been captured on upper and lower side,
showing decrement and increment in elevation.
Following showing map of DEMs is showing the accuracy of above mentioned results.
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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16. Landslide Hazard Modeling
Issues and Problems
This is going to be the most important part of the assignment, as this makes its harder and time
consuming.
1. First, the arc GIS is not always generating the raster accurately. Sometimes, it shows that
results of that data which have been done previously.
2. Secondly, in Auto-cad, I am completely unable to generate graph. But, don‟t know the
error is. I have tried so many ways, defined as follows:
a. Firstly, type „pl‟ in Command line, and paste the XY values. NO result.
b. Then tried by, typing „MULTIPOINT‟ in Command line, and paste the XY
values. NO result.
c. At the end, copy XY values in notepad. Types „LINE‟ on the start, followed by
values. And save it with „Name.scr‟. This will generate „Auto-cad Script‟ file.
Now open the Cad, in the Tool bar, Select „Run Script‟ and navigate to the saved
file with extension „.scr‟. Still NO result.
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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17. Landslide Hazard Modeling
Conclusions
By performing the whole practical, and comparing the results from different sources and ways.
It is cleared that in the year 2012, the study area, near the high elevations, is more prone to
excavation. There exists a much deeper but a gentle cut in the higher elevated areas. While the
lower areas were generally like a regular hilly area.
While in case of year 2008, the area was having steep dip at the elevated portion as compared to
the lower portion.
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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18. Landslide Hazard Modeling
Reference
1. http//: training.fema.gov E IWeb E ICourses E
Atiqa Ijaz Khan
Institute of Geology (Session: 2013-15)
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Unit
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