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GISC9312 – Geospatial Visualization
Assignment 1- 3D Analysis in ArcGIS
19 Tasker Street• Saint Catharines• Ontario• L2R 3Z9 Phone# 905-246-6683•Email: [email protected]
April 16, 2016 GISC9312-D1
Mrs. Janet Finlay GIS-GM Program Coordinator Niagara College 135 Taylor Road Niagara-on-the-Lake, ON L0S 1J0
Dear Mrs. Finlay,
RE: GISC9312 D1- 3D Analysis in ArcGIS
This letter serves as a formal submission of Assignment 1 (3D Analysis in ArcGIS) for the course Geospatial
Visualization.
Assignment 1 serves as an introduction to creating and analysing three-dimensional data utilizing tools
available in ArcMap and ArcScene. The purpose of assignment 1 is to gain practical experience analysing
TIN models and subsequently utilizing the 3D Analysis extension to execute Slope, Aspect and Hillshade
analysis for the study area.
On completion of this assignment, I was able to understand and interpret the results of various terrain
analyses; also create and interpret the results of the line of sight tool available. The knowledge gained
would be useful in further developing my skill set as an aspiring GIS professional.
Please feel free to contact me anytime at (905)-246-6683 or [email protected], if there are any
questions or concerns with regards to this assignment. I look forward to your comments and feedback.
Kindest Regards,
Jonathan Jn Baptiste B.Sc. GIS-GM Certification Candidate J.J.B Enclosure: 1. JNBAPTISTEJGISC9312D1.docx 2. JNBAPTISTEJGISC9312D1.jpg
April 16, 2016 GISC9312-D1
19 Tasker Street• Saint Catharines• Ontario• L2R 3Z9 Phone# 905-246-6683•Email: [email protected]
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Table of Contents 1.0 Introduction ............................................................................................................................................ 1
2.0 Questions and Discussion ....................................................................................................................... 2
2.1 East Facing Slope ................................................................................................................................. 2
2.2 Aspect.................................................................................................................................................. 3
2.3 Slope Ranges ....................................................................................................................................... 4
2.4 Line of Sight A ..................................................................................................................................... 8
2.5 Line of Sight B .................................................................................................................................... 10
2.6 Hillshade Analysis .............................................................................................................................. 13
3.0 Conclusion ............................................................................................................................................. 18
4.0 References ............................................................................................................................................ 19
List of Tables Table 1: Slope Values .................................................................................................................................... 6
List of Figures Figure 1: Area of Interest- Slope Value ......................................................................................................... 2
Figure 2: Area of Interest- Aspect Value ....................................................................................................... 3
Figure 3: Slope Ranges-Entire Area ............................................................................................................... 4
Figure 4: Slope facing Glendale Campus ....................................................................................................... 5
Figure 5: Line of Sight Illustration ................................................................................................................. 8
Figure 6: Line of sight from Vantage Point A ................................................................................................ 9
Figure 7: Line of sight from Vantage Point B .............................................................................................. 10
Figure 8: Vantage Point B elevation Value .................................................................................................. 11
Figure 9: Vantage Point B target Elevation Value ....................................................................................... 12
Figure 10: Vantage point A Elevation Values .............................................................................................. 13
Figure 11: Sun Angle Calculation ................................................................................................................ 14
Figure 12: Fully Shaded- NOTL, ON ............................................................................................................. 15
Figure 13: NOTL-3D ..................................................................................................................................... 17
April 16, 2016 GISC9312-D1
19 Tasker Street• Saint Catharines• Ontario• L2R 3Z9 Phone# 905-246-6683•Email: [email protected]
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1.0 Introduction The contents of this report seeks to highlight the use of ArcGIS’s 3D Analyst Extension,
to undertake three dimensional data analysis of the Niagara Escarpment and its
surroundings. A Triangulated Irregular Network (TIN) will be created from Ontario Base
Map data of the study area. Subsequently, TIN surface analysis tools namely aspect,
slope and hillshading, to name a few, are to be executed to perform various surface data
queries.
April 16, 2016 GISC9312-D1
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2.0 Questions and Discussion
2.1 East Facing Slope What is the slope (in degrees) and the aspect (also in degrees) of the east facing slope at the
Glendale Avenue interchange of the QEW.
As seen in Figure 1 below, the Slope (in degrees) for the east facing slope at the Glendale
avenue interchange of the QEW is 8.072965.
Figure 1: Area of Interest- Slope Value
April 16, 2016 GISC9312-D1
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Figure 2 below displays the Aspect (in degrees) of 102.528809 for the east facing slope
at the Glendale avenue interchange of the QEW.
Figure 2: Area of Interest- Aspect Value
2.2 Aspect What does aspect mean? What is an aspect of zero degrees?
Aspect is the slope direction on a terrain surface. Aspect is measured clockwise starting
North as 0° to 360°. (GIS Dictionary – Geospatial Definition Glossary, 2016). An aspect
of zero degrees suggest the terrain is facing North however, an aspect of -1 is considered
flat terrain.
April 16, 2016 GISC9312-D1
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2.3 Slope Ranges What range of slopes is found on the Niagara Escarpment that faces the Glendale Campus,
immediately south of the campus?
Figure 3 below shows the range of slope values for the entire area being between 0 and
57.09%. Areas in green represent flatter terrain whereas red represent steeper terrain.
Figure 3: Slope Ranges-Entire Area
However, the range of slopes for section of the Niagara Escarpment facing the Glendale
Campus as identified in Figure 4 below are between 5.63 % and 41.73%.
April 16, 2016 GISC9312-D1
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Figure 4: Slope facing Glendale Campus
Table 1 below shows the slope values at various points along the section identified in
Figure 4 above.
April 16, 2016 GISC9312-D1
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Table 1: Slope Values
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2.4 Line of Sight A From a point atop the Conservation area, create a line of sight that proceeds (approximately)
through the Glendale Campus. Why can the areas that are indicated as not in the line of sight
not be seen?
A line of sight is a graphic line between two points on a surface that shows where along
the line the view is obstructed. The color of the line indicates the locations where the
surface is visible and where the surface is hidden. (ESRI, 2008)
(ESRI, 2008)
Figure 5: Line of Sight Illustration
April 16, 2016 GISC9312-D1
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Figure 6 below shows the line of sight from Vantage Point A through the Glendale
Campus. The black dot signifies the observation point which was offset by 1.67 m
(observer’s height). The small line of green indicates what can be seen by the observer.
The blue dot indicates an obstruction point in the observer’s line of sight and the red
shows the obstructed area between the observation and target point identified as a red
dot. The areas indicated as not in the line of sight cannot be seen by the observer
because these areas are at a lower elevation than that of the observer, considering the
observer is determining what is visible by looking straight ahead. From this vantage point
the target cannot be seen.
Figure 6: Line of sight from Vantage Point A
April 16, 2016 GISC9312-D1
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2.5 Line of Sight B From a point atop the Conservation Vantage Point B, create a line of sight that proceeds through
the QEW/Glendale Highway interchange berm. Why can the areas that are indicated as not in
the line of sight not be seen?
Error! Reference source not found. shows the line of sight from vantage point B through
he QEW/Glendale Highway interchange berm. The observer offset was also set at 1.67m
(observer’s height). As previously indicted, red indicates areas obstructed from the
observer’s point of view and green areas are those visible to the observer. The blue dot
is an obstruction point.
Figure 7: Line of sight from Vantage Point B
Although the target is not visible to the observer from vantage point B, there is more
visibility from this point. This is due to the fact that vantage point B is at a lower elevation
value of 147.688 as seen in Figure 8 Error! Reference source not found.below.
April 16, 2016 GISC9312-D1
19 Tasker Street• Saint Catharines• Ontario• L2R 3Z9 Phone# 905-246-6683•Email: [email protected]
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Figure 8: Vantage Point B elevation Value
April 16, 2016 GISC9312-D1
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Figure 9 below shows the elevation value of the target from vantage point B.
Figure 9: Vantage Point B target Elevation Value
Compared to vantage point A, where the observer’s elevation is 170.734 and the target
elevation is 120.20, as seen in Figure 10, there are more features with the same elevation
value as that of the observer from vantage point B, therefore more green areas are seen
in the line of sight.
April 16, 2016 GISC9312-D1
19 Tasker Street• Saint Catharines• Ontario• L2R 3Z9 Phone# 905-246-6683•Email: [email protected]
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Figure 10: Vantage point A Elevation Values
2.6 Hillshade Analysis Create a hillshade analysis for the two OBM tiles you have been working with. The sun specs
should be estimated given the following: March 21st, noon (eastern standard time). Determine
only those areas that experience full shade at this date/time.
Hillshading is the hypothetical illumination of a surface according to a specified azimuth
and altitude for the sun. (ESRI, GIS Dictionary, 2016). To determine the Azimuth and
altitude for the sun at the specified date and time, the Sun Angle Calculator,
http://www.susdesign.com/sunangle/ was utilized. Figure 11 below shows the output of
April 16, 2016 GISC9312-D1
19 Tasker Street• Saint Catharines• Ontario• L2R 3Z9 Phone# 905-246-6683•Email: [email protected]
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the sun angle calculation based on the date and time specified in the terms of reference.
(Gronbeck, 2009)
Figure 11: Sun Angle Calculation
As a result the Azimuth of 153.53 degrees and Altitude of 43.51 will be used when creating
the hillshade for the area of interest. Figure 12 below show the locations in Niagara-on-
the-Lake, ON which experienced full shade on March 21, 2016 at 12 noon.
April 16, 2016 GISC9312-D1
19 Tasker Street• Saint Catharines• Ontario• L2R 3Z9 Phone# 905-246-6683•Email: [email protected]
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Figure 12: Fully Shaded- NOTL, ON
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To obtain a 3D view of the area of interest, the datasets were viewed in ArcScene and
exported as a JPEG. Figure 13 below shows the formal layout of the area in 3D.
April 16, 2016 GISC9312-D1
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Figure 13: NOTL-3D
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3.0 Conclusion The analysis capabilities of these tools make them applicable in so many aspects in
geomatics. Using the study area as an example, it was possible to determine using the
slope tool, where the steepest parts of the study area were and the aspect tool allowed
the determination of which direction the slopes of the study area faced. It was also
possible to determine what targets were visible or not, from a specific vantage point using
the line of sight tool. The 3D Analyst Extension and its tools are very powerful, useful,
and easy to use set of tools.
April 16, 2016 GISC9312-D1
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4.0 References ESRI. (2008, February 29). Creating a line of sight. Retrieved from ArcGIS Desktop 9.2 Help:
http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?id=2946&pid=2941&topicname=Creating
_a_line_of_sight
ESRI. (2016). GIS Dictionary. Retrieved from http://support.esri.com/:
http://support.esri.com/en/knowledgebase/GISDictionary/term/hillshading
GIS Dictionary – Geospatial Definition Glossary. (2016). Retrieved from GIS Geography:
http://gisgeography.com/gis-dictionary-definition-glossary/
Gronbeck, C. (2009). Sun calculator. Retrieved from sustainable by design:
http://www.susdesign.com/sunangle/
Finlay, J. (2015). GISC9312 – Geospatial Visualization, Assignment 1, Terms of Reference
ArcScene Logo
www.gi-geoinformatik.de
Accessed: April 17, 20016
ArcMap Logo
www.waterscc.com.au
Accessed: April 17, 20016
ESRI Logo
nordpil.com
Accessed: April 17, 20016
