Faculty of Environmental Studies
Final WATgreen Report:
Comprehensive Manual on
GPS and Campus Tree Mapping
For ERS 285
Table of Contents
7.1 Systems Diagram Explanation
Appendix I: International Comparative Reports and Software
Appendix II: Hazard Tree Evaluation Form
Appendix III: Where in the World is Waterloo? (1998)
Appendix IV: Microsoft ACCESS database
Appendix V: PathFinder GPS Differential Correction Software
Appendix VI: AutoCAD Software, Digitized Campus Map and Tree Label Points
Appendix VII: Moving Points in AutoCAD
Appendix VIII: Linking Microsoft ACCESS and AutoCAD
f) Sections of the final report were contributed by:
- Executive Summary Aaron
- Introduction to Project Diane
- Background Diane
- Comparative Reports and Projects Diane
- Introduction to Manual Aaron
- Actors Analysis Aaron
- Systems Diagram Explanation Aaron
- Conceptual Framework Aaron
- Methodology Diane
- Qualitative Analysis Aaron and Colleen
- Quantitative Analysis Diane and Nick
- Acquired Knowledge and Skills Aaron and Nada
- Effectiveness of GPS Surveying Method Aaron
- Impact of GPS Aaron
- Limitations Aaron and Costas
- Conclusions Aaron and Diane
- Recommendations Diane
- Acknowledgements Aaron
partially attend most meetings.
h) Aaron mapped the trees, while Colleen and Diane worked on other tree analysis.
2.0 Executive Summary
The ERS 285 Tree Mapping Group had three goals for this project, they were: (i) to complete a working, readily accessible tree database for the Physics and Needles Hall buildings at the University of Waterloo, (ii) to initiate this project and to permit others to replicate it and eventually complete a campus-wide tree database for the University of Waterloo, and to (iii) further the University of Waterloos sustainability goals through the ERS 285 Greening the Campus initiative. Quantitative data in the form of GPS locations and qualitative data such as physical attributes and health status was to be collected for the trees on campus. The final product was to be a spatially referenced map with the location of the trees around a particular area of campus and to begin the campus-wide tree database.
Two groups, consisting of three ERS 285 students each, chose the Physics Building and Needles Hall buildings to map. The Needles Hall tree-mapping group was successful in mapping the trees around their building but the Physics group was not. Instead of producing the anticipated final product, the Physics group decided to prepare a Comprehensive Manual on GPS and Campus Tree Mapping. This manual will provide a framework for future students who will attempt to map another part of campus. The manual provides a detailed methodology, major limitations to the project, and recommendations for future groups.
3.0 Introduction to Project
WATgreen: Greening the Campus is an educational initiative meant to have students, faculty and staff collaborate on ideas about how to make "a positive contribution to the resolution of environmental issues" facing the University of Waterloo campus (University of Waterloo, 1999). The underlining focus for these 'ideas' is the improvement of the campus environment quality, while decreasing the University operating costs, particularly to the Plant Operations Department. An instrument facilitating the WATgreen goals is the course ERS 285: Greening the Campus, which encourages the sustainable development (economic growth which maintain the livelihood and integrity of the campus environment and surrounding area) of the University. This type of 'environmental stewardship' is also a goal of the University's Master Plan (1992).
The Comprehensive Manual on GPS and Campus Tree Mapping provides a step-by-step review of the procedures needed to complete a readily accessible on-campus tree database (including spatial location as referenced by a Global Positioning System and attributal information). The completed database proposes to help improve University of Waterloo's air quality, by implementing a long-term information system containing information regarding campus trees. The issue of air quality in the Kitchener-Waterloo region, and even more localized at the Waterloo campus level, is a significant component in the Universitys attempt to achieve sustainable development (Lamb, 2000).
An objective of the completed database is that the collected information will permit analysis of the "campus environment quality" (a form of sustainable development), with the specifics regarding tree health and consequential air quality improvement (or degradation). This information can also be used in evaluating the presence of diseases and potential for spreading to neighbouring trees and whether the documented trees need to be removed (Amorosi et al., 2000).
Campus trees can both provide and indicate campus health (Lamb, 2000). Trees provide health by fixing carbon to oxygen during the photosynthesis cycle, and indicate campus health by their vitality and resulting longevity (Art, 1993).
The scope of the project includes background information regarding WATgreen projects and other comparative international reports. The scope also includes the steps required to complete a tree database, and recommendations for future tree-mapping groups.
The location of the trees will be determined by using the Global Positioning System. Global Positioning Systems (GPS) was created by the United States Department of Defense for an estimated cost of $16 Billion (McKenzie, 1998). The system uses the NAVSTAR system of 24 satellites at very high altitudes (18 000 km), with each satellite orbit designed for maximum efficiency (Treitz et al., 1993). In order to achieve GPS co-ordinate readings, the GPS unit transmitter must detect a minimum of four satellites (Campbell, 1998). As such, the orbits are designed so that this minimum number of satellites can be obtained from any point on the earth, at any time
A GPS co-ordinate is obtained when the transmitter measures position, velocity and time from the recorded satellites (McKenzie, 1998). It should be noted that the more satellites detected by the GPS transmitter, the more accurate the readings tend to be. Once calculated, GPS units must undergo differential correction. This is when the obtained GPS co-ordinate values are compared to other GPS values. This is explained further in the Quantitative Analysis section of the Methodology.
The location of a particular tree from the GPS system will give a general area of approximately 143m by 75m. Using equations, the accuracy can be increased to 15m by 8m. Using the equation to correct the readout once more will offer an accuracy of up to ± 1.0 metre from the actual location (Elliot, 2000).
A Geographical Information System (GIS) is an information system (like Microsoft ACCESS), but has an added spatial component (Campbell, 1998). A GIS is a multipurpose tool used in "data management, mapping and analysis" (Campbell, 1998). A Computer Aided Design (CAD) system works to "improve the speed and accuracy of map production" (Campbell, 1998).
University of Waterloo Plant Operations Department uses AutoCAD software, and as such already has a digitized map of the campus available for use. This is the software that will be used to display the label points, which will be displayed in a layer that will be overlayed with the digitized campus map. The campus map is included on the attached cd-rom disc.
The completed tree-mapping database is unlike any documented project done for (or by) the University of Waterloo (Elliot, 2000), and as such, previous WATgreen projects are of minimal utility. However, there is extensive background material available in the WATgreen database regarding forms of environmental stewardship such as alternatives in campus landscaping, and improving landscaping through the use of a GIS system.
The previous WATgreen reports examining landscaping and campus sustainability include the project titled Herbicide Use at the University of Waterloo: Practices, Attitudes and Perceptions (1992), and the research work completed by Cento et al. (1991) which examined "concepts of sustainability and alternative landscaping" (Hassan, 2000). Geographic Information System: A Turf Management Implementation (1993) involved addressing the reduction of synthetic chemicals used on campus turf through the use of a Geographical Information System (GIS). A WATgreen report concerning campus trees includes a campus-wide tree inventory that was completed in 1994.
These reports examined University of Waterloo's Plant Operations Department landscaping practices. As such, the aforementioned reports are useful when indicating outcomes such as potential longstanding factors that may be affecting campus tree vitality. The tree inventory report completed in 1994 can be compared with the current inventory (as yet undetermined), which would indicate which trees/species have been removed and/or planted.
An international comparative research company by ACRT, Inc. examines ways of completing street and park tree inventories through the use of GPS and laser survey equipment, as shown in Appendix I (ACRT, Inc., 2000). This is done through the use of different software, and will be discussed further in the Recommendations section.
The Comprehensive Manual on GPS Campus Tree Mapping was created in response to several limitations noted in this project, some within the project members control and others beyond their control. These limitations resulted in GPS data not being collected for the trees around the Physics Building. Needles Hall was the only successfully mapped area of campus for Spring term 2000. The "Physics" project group decided that if the original goal of completing GPS mapping for the Physics Building could not be accomplished, then the final deliverable project would be a "reference guide" to help future groups in mapping areas of the campus.
7.0 Conceptual Framework
This project came to fruition when Lynne Elliot, the GIS and instruction manager, came to the Spring 2000 ERS 285 Greening the Campus class and asked for help with a project involving GPS to map the trees on a particular area of campus. The project suggested by Lynne Elliot was appropriate because it would make "a positive contribution to the resolution of environmental issues" (Elliot, 2000) facing the University of Waterloo, which is a criterion for an ERS 285 Greening the Campus project. When completed, the project will help to improve the air quality not only on campus but in the region of Kitchener-Waterloo as well. Additionally, the qualitative and quantitative data collected about the trees on campus would permit an analysis of the overall campus environmental quality.
There was no actual conceptual framework for this project. The project group was given a tool and told to use it to accomplish a particular task. The group already knew the outcome of the project before it had even begun. To prepare for the project, the project group had to organize time and human resources as well as learn to use GPS, PathFinder, ACCESS, and AutoCAD.
The project group was not only to learn how to use quantitative research tools, such as computer programs and GPS, but qualitative research methods as well, such as tree identification and health and the importance that each tree has on campus.
There were 3 general goals of the ERS 285 Tree-Mapping Project Group:
A methodology was subsequently developed that would allow the project group to collect all of the data that the database and the spatially referenced map required. The methodology had to take the limitations of the project into account.
7.1 Systems Diagram Explanation:
The system that pertains to this project contains biophysical, anthropocentric and technological aspects. In environmental studies, a system is "a set of components and their interrelationships" (Murphy, 1998). It is essential to analyze the system that the project is a part of so that the entire scope of the issue can be distinguished. As well, it is important to look at the project systematically to see how things interact and relate to each other.
The physical boundary of our study area is around the Physics Building on the University of Waterloo Campus, which is considered the "UNIVERSE". The group is analyzing all of the trees around the building therefore the entire universe will be sampled. There is another boundary referred to as the PROJECT BOUNDARY. Within the PROJECT BOUNDARY is the UNIVERSE. Everything within the PROJECT BOUNDARY is considered an internal factor.
Internal factors include the trees that are being studied. The trees are the focus of the system because all other factors are stemmed from the trees. First, the University Arborist Tim Ernst gave the project group input to what the database must include and then Larry Lamb gave input to what the database should include. This leads to the problem statement being established "Locating and collecting information about trees using GPS and identifying the type of species and their health can improve air quality on campus". This lead to the methodology which is outlined in the systems diagram (see Systems Diagram on next page). When the data was collected, it was recorded on field notes then input into electronic resources such as Access.
There are also external factors that are involved in the system. These are primarily biophysical factors such as biogeochemical cycles as well as animals, insects, and disease. There are, however, many anthropogenic factors that affect the trees. Human factors such as roads that are close to trees, soil compaction around the base of trees from paths, infrastructure such as lamp posts and building structures, and removal of soil around trees all compromise tree health. University of Waterloo Plant Operations does landscaping work and applies road salt, which can also damage trees. Air pollution is another consideration because Kitchener-Waterloo has a reputation for poor air quality. If we think of things as a whole, then we can manage what we have and only then can sustainability be achieved.
It is important to identify the key actor groups involved and the type of issue at hand to fully understand the different perspectives of a project. First, the type of issue must be addressed. The issue that this project addresses is an Advocacy issue. Such issues are characterized by certain groups who feel strongly about it, but the issue itself is not very publicly visible and does not generate a strong public response.
Next, the actors involved in the project study must be identified. In the context of this particular project, there are a number of actors involved. There are three categories of actors; their definitions and the stakeholders involved are outlined below:
Core Actors (continuously and intensively involved)
Supporting Actors (less involved but still have a significant impact)
Shadow Actors (affected by what happens but do not get involved)
A tree-mapping project utilizes both qualitative and quantitative data collection techniques in order to create a database containing the spatial location and attributal information of the trees. As a formal statement of research was aforemetioned, the data collection techniques involve deductive logic (Palys, 1997). This type of reasoning entails specifying a formal statement of research, only after a theory has been developed about the phenomenon. The phenomenon is then observed to indicate whether the theory is valid, and after which the study topic can either by subjected to another theory (if it proved to be invalid) or to empirical generalization (if the theory proved to be valid).
Palys (1997) indicates that a universe "is a theoretical aggregation of all possible sampling elements", to which a tree-mapping group must specify a particular area to map-out. An example of a set universe would be that of University of Waterloo's Physics building. The universe could then have its borders defined by the sidewalks that surround the perimeter of the building. All trees within this border would then be examined qualitatively and quantitatively.
This project defines a tree as having a diameter at breast height (d.b.h.) of 7cm or greater (Lamb, 2000). Any species having a d.b.h. less than 7cm is considered a sapling (Lamb, 2000). Depending on the defined universe, there may be some discrepancy when determining which tree or sapling to map.
The University Arborist, Tim Ernst, will aid the group in identifying qualitative characteristics of trees such as maintenance history, health, site conditions, target (what built features surround the tree), defects, hazard rating, and hazard abatement (see Appendix II). As well, the ecology lab manager, Larry Lamb will assist the group with measuring tree height and diameter, identifying the species (botanical and common name) as well as pests/diseases. Other factors that must be noted are site location, date of inspection, date of last inspection, and inspector.
There were four basic categories that were observed and the health identified:
This category includes roads and pathways, soil compaction, buildings close by, soil removal, landscaping, salt use (winter), frequency of use, and proximity to bike racks.
Some of the common characteristics
of branches that were identified are:
Some common characteristics of the trunk that were identified are:
Some of the common characteristics of
the roots that were identified are:
The Ecology Lab Manager, Larry Lamb, aided the group in identifying qualitative characteristics of trees such as maintenance history, health, site conditions, target (what built features surround the tree), defects, hazard rating, and hazard abatement (see Appendix II). As well, Larry Lamb assisted the group with measuring tree height and diameter, identifying the species (botanical and common name) as well as pests/diseases.
All of the information was recorded into an Access database created by Lynne Elliot (GIS and Instruction Manager) (see Appendix IV) and on field notes (see Appendix II). The database was created with input from Tim Ernst and this project group. Tim Ernst will be using the completed Access database with a digitized map of the University in AutoCAD format (See Appendix VI) for further analysis. The aforementioned field notes consisted of the Hazard Tree Evaluation Form (see Appendix II) as well as an extensive other comments area reserved for observations that are not included in the Hazard Tree Evaluation Form.
This section will include a step-by-step manual of how to proceed with a tree-mapping project. It should be said that there is other software available to complete this project, but by using the mentioned software no extra training is required for the Plant Operations staff as they currently use Microsoft ACCESS and AutoCAD software. As such, the quantitative analysis uses ACCESS, PathFinder and AutoCAD as the key actors are already familiar with the software.
To obtain a GPS co-ordinate reading, locate to the tree area to which the desired reading is for. Turn on the GPS transmitter and select Data Capture from the menu items. Select Satellite Status and try to obtain a PDOP (shown in the lower right corner of the GPS transmitter screen) to a reading of less than 4. The PDOP value indicates the level of accuracy, where a value of 4 or less indicates good accuracy, a value of 5 to 8 indicates an acceptable accuracy, and a value of 9 or greater indicates a poor GPS co-ordinate reading (Elliot, 2000). The GPS transmitter user may need to move away from the object (as buildings and trees can interrupt the satellite signal) to obtain a good or acceptable reading. This is where section 9.2.4 Moving Co-ordinate Points in AutoCAD comes into place. So if the GPS co-ordinate is obtained away from the object, measure the distance and direction through the use of a compass and measuring tape (See Appendix III).
Once the PDOP readings are organized and acceptable, select Open Rov. File from the main menu. By opening this file, the transmitter will automatically record values. Allow the transmitter to record values for one minute and stop the recording by selecting Close File. Record the File name for future use.
This step must be completed within 24 hours from the time of the first recorded GPS co-ordinate reading. In order to correct the data points using the MAD Lab laptop computers, complete the following steps:
a) Open AutoCAD and select Open a Drawing and select the AutoCADUWMap.dwg included on the cd-rom disc. Overlay this drawing with the export file from PathFinder (See Appendix VI).
This is a step that may not be applicable to all or any of the obtained tree co-ordinate points. This step may be necessary depending on how close (or far) the transmitter was from the trunk of the tree when the GPS tree co-ordinate reading was obtained. This is explained further in Appendix VII.
This is a complex step, but is explained in Appendix VIII. This step permits easy display of tree attribute information (from the ACCESS database) by simply clicking on a tree co-ordinate label point in AutoCAD. The linking of ACCESS and AutoCAD produces a GIS type file, but through the use of software the Plant Operations staff are familiar with.
This project had a lot to offer the students that initiated its implementation. Project members have gained knowledge of computer/technical skills such as GPS, Pathfinder, Access, and AutoCAD as well as different surveying skills. Qualitative tree identification techniques were also learned and how humans have an influence on trees. Project members were also exposed to group logistics such as organization, communication, work ethic, co-ordination, and co-operation. The project group is now increasingly aware of the importance of campus environmental health and its current state.
This project not only was used to create a spatially referenced map of the trees on campus; it was also used to evaluate the effectiveness of using GPS for a project such as this. GPS is more effective than other methods of mapping trees such as surveying. GPS is straightforward, easy to use and efficient. Surveying the trees on campus would require more students to partake in the project and would require considerable more time in training on how to use surveying equipment. Using GPS for a project such as this also offers the opportunity for students to learn this valuable application and apply it in a workplace setting in the future.
This project has an impact at many different levels. The goal of the ERS 285 course is to further sustainability on campus with this particular semester focussed on air quality. This project will indicate environmental quality and will also help to improve the air quality on campus. If the database is used to assess the health of the trees on campus and to manage them, then air quality should improve. On a larger scale, trees are important because they fix carbon to oxygen during photosynthesis, which promotes environmental health in all communities in all parts of the world.
Accuracy of GPS:
Further to the limitations that the project has, there are weak links in the system. These weak links are outlined in red on the "Tree Mapping System Weak Links" diagram on the next page. Explanations of the weaknesses are as follows:
Communication Links Tim Ernst and Larry Lamb wanted particular things to be
included in the database. Tim Ernst was the principle "client" therefore his specifications were considered most important. More communication between the Tim and Larry and the project group could have resulted in a database that both could more effectively utilize.
Universe The universe selected was too large for the time frame.
Project Boundary Either more time or more group members or fewer trees would be
required to successfully complete the project.
Lynne Elliot (and M.A.D. staff) This was a project like no other in the history of
WATgreen at the University of Waterloo. The project was just as new to the M.A.D. staff as it was to the project group. Because of the uniqueness of this project, the M.A.D. staff had to learn many new functions of the software applications that were used for this project. The quick turn-around time from learning the new functions and then teaching them to the project group members was quite short and may have caused unnecessary time mismanagement difficulties. In addition, there were times when the competing demand for resources prevented us from getting the help that we needed.
Field Notes The Hazard Tree Evaluation Form was too in-depth to be used as a
qualitative checklist for tree evaluation. Either Tim Ernst would have to go out with us or an information seminar on what to look for when evaluating the trees would have been useful. The project group did not have the expertise to fully complete the Hazard Tree Evaluation Form. If the therefore there would be an overlap of work because someone will still have to go out and do that.
GPS The accuracy of GPS is questionable. More accuracy would occur if the GPS
could be used at the base of trees instead of outside of the area below the trees crown. As well, the data must be corrected within twenty-four hours of collection therefore there is not much leeway for technical difficulties.
This group project concludes by stating that the most effective and efficient method for mapping trees on campus is through the use of a GPS system. The creation of the Comprehensive Manual on GPS Campus Tree Mapping indicates that a spatially referenced map of campus and a campus-wide tree database is possible to accomplish and has utility in determining campus tree health.
This group also concludes by stating that there are various limitations to a project such as this, many of which may be out of the students control. As such, this project requires organization, dedicates support staff from M.A.D and other actors that are intensely involved in the completion of this database. The presence of these various limitations, and the need for very knowledgeable support staff is why this group decided to complete a ready-to-use manual with hopes that this project will follow through to completion.
This tree-mapping group recommends that this report be used as a comprehensive manual (a framework) when implementing a campus tree-mapping project. However, this group does recommend that the campus tree-mapping projects be implemented during the winter months. This will help in eliminating the high (i.e. low accuracy) PDOP readings from the GPS transmitter by eliminating the interference obtained from the tree foliage. This will also help in minimizing the amount of tree co-ordinate label points that need to be moved in AutoCAD.
Another recommendation would be to make sure that all of the project actors are prepared for the campus tree-mapping inventory. This refers to ensuring that the MAD staff, University Arborist and Ecology Manager all have similar views about the project, and that they know how to get to the final report (either through knowledge of all applicable software or through knowledge of qualitative tree information).
This tree-mapping group also recommends that future groups set universe boundaries that are viable. This group set the boundary too large (which contained approximately 50 trees), resulting in not completing the project.
Another recommendation would be to investigate the usage of more user-friendly GPS and GIS software (examples of this are shown in Appendix I). This could only be implemented if the Plant Operations staff are willing to learn how to use this software, other than their preferred Microsoft ACCESS database and AutoCAD systems.
The ERS 285 Tree Mapping Project Group would like to thank:
ACRT Environmental Services. 2000. Urban Forest Technology [Online]. Available:
http://www.acrtinc.com/uf_tech.html [July 19, 2000].
Amorosi, Aaron, Nickolas Bartok, Colleen Ditner, Costas Farassoglou, Diane Redekop,
and Nada Sutic. "Tree Mapping at UW Using GPS." U of Waterloo, Waterloo, Ontario. 13 July 2000.
Art, Henry W. 1993. The Dictionary of Ecology and Environmental Science. New York: Henry Holt and Company.
Bamford, T., and J. Franssen. 1994. Preliminary Tree Inventory of the UW Campus. Waterloo: University of Waterloo WATgreen Report.
Berridge, Levinerge, Greenberg Ltd. 1992. Campus Master Plan: Framework for
Development. Waterloo: University of Waterloo.
Campbell, John. 1998. Map Use and Analysis. 3rd Ed. Boston, MA: WCB/McGraw-
Chao, S., Malcolm Chiu, Rene Ho, Grace Wong and Gerry Yen. 1993. Geographic Information System - A Turf Management Implementation. Waterloo: University of Waterloo WATgreen Report.
Cento, G., C. McLaughlin, J. Proud, T. Rehder and P. Smith. 1991. A Rationale for the Establishment of Alternative Landscape Practices at the University of Waterloo. Waterloo: University of Waterloo WATgreen Report.
Elliot, Lynne. Personal Interview. 18 May 2000.
Elliot, Lynne. 2000. Moving Trees in AutoCAD. Mapping and Design Lab: University
Hassan, S. 2000. Campus Landscape Study: The conversion of Turf Areas to
Alternative Forms of Ground Cover. Waterloo: University of Waterloo.
Lamb, Larry. Personal Interview. 30 May 2000.
McKenzie, Ian. 1998. Where in the World is Waterloo? University of Waterloo:
Faculty of Environmental Studies.
Murphy, Stephen. 1998. ERS 100 Course Notes. Waterloo: Coursewares.
Palys, Ted. 1997. Research Decisions: Quantitative and Qualitative Perspectives. Toronto: Harcourt Brace & Company, Canada.
Treitz, P. et al. 1993. Differential Global Positioning System: potential for geographical information system database management. Waterloo: University of Waterloo.
Tripp, C., and S. Keith. 1992. Herbicide Use at the University of Waterloo: Practices, Attitudes and Preceptions. Waterloo: University of Waterloo WATgreen Report.
University of Waterloo. 1999. WATgreen: Greening the Campus [online]. Available:
http://www.adm.uwaterloo.ca/infowast/watgreen/WATgreen [May 26, 2000].
Unknown. 1998. Where in the World is Waterloo? Waterloo: University of Waterloo.