hazard modeling

Landslide Hazard Modeling

Atiqa Ijaz Khan Institute of Geology (Session: 2013-15)



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



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



Chapter 01

before 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.

Man Made Hazards:

It includes:

Viruses, Weapons of mass destructions, Chemical split,

Explosions, Chemical and biological agent, Terrorism.

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.

B



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.



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.



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



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.



Fig 2: Shapfile_2008

2. Exported shape file of year 2012.

Fig 3: Shapefile_2012



3. Raster date of year 2008.

Fig 4: Raster Data_2008

4. Raster data of year 2012. (Fig 5: Raster Data_2012)



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



7. The final output of cut/fill result in the arc GIS is as follows: (Fig 8: Results in Arc GIS)



8. And the same output in the Auto-cad is as follows: (Fig 9: Results in Cad)



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.



Fig 11: Raster Comparison



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.



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.



Reference

1. http//: training.fema.gov E IWeb E ICourses E C Unit .pdf

hazard modeling

Education

hazard analysis

hazard map

effects of hazard

type of hazard

hazard modeling052

hazard modeling05ii

hazard identification04d

hazard modeling06 figure