Field Activity #4: Creation of a Digital Elevation Surface using critical thinking skills and improvised survey techniques

Introduction

Sampling is a technique used to investigate a population by gathering data from a small portion of the entirety. Sampling is used to save both time and money and is used for many studies. Sampling provides an overall look at the spatial variations of a phenomena within a study site. There are three sampling methods; 1) random ,2) systematic, 3) stratified. The objective of the lab was to create a landscape containing a wide range of elevation and collect and record the elevation through systematic point sampling. This means that samples were collected evenly throughout the study area. In our case, the samples were in form of centimeters and represent elevation.

Methods 

               Figure 1: The landscape was created
with all of the parameters needed. 

The elevation of the landscape was collected by taking measurements through a systematic point sampling technique. In order to accurately portray the topography of the landscape measurements had to be taken fairly often at a regular interval. The landscape was created in a 45 by 45 in  (114 by 114 cm) sandbox located east of Philips Hill. Designing the landscape involved several parameters. It was required for the landscape to have a hill, ridge, valley, depression, and a plain. Creation of the landscape was done by hand (Figure 1). Materials given to us was string, wall tacs, tape, measuring tape, and a meter stick. Using the wall tacs and meter stick, every 5 cm was marked on all 4 sides of the sandbox. After placement of the tacs, the string was used to create a grid over the top of the landscape (Figure 2). Our sea level or zero elevation was the actual ground. This was chosen to ensure that negative values would not be measured.

         Figure 2: The string was wrapped around the
 tacs to create a grid over the landscape

To collect the elevation points a metal hanger was straightened and stuck into the ground within one of the grid squares (Figure 3). Once ground was met, the hanger was taken out and placed against a meter stick to read the measurement in centimeters (Figure 4).

Figure 3: The grid helped keep the measurements
 organized and at set increments of 5 cm

Figure 4: Elevation collection

The elevation points were placed in an excel file with 3 columns (Figure 5). The grid had a column for X, Y, and Z so that each point could be plotted on a grid with the elevation. This will help in later visualization of the landscape within ArcMap.

Figure 5: Excel table showing set
 up of elevation measurements 

Results

The overall table consisted of over 400 sample points taken of the to show the elevation change (relief) of the landscape we created. The excel table is the most important result of the project. Using the correct formatting that can be read in ArcMap, the goal for future work is to input the table to create a topography model of the landscape through various processing procedures.

After running statistical measurements of the Z column (which holds the elevation in cm) various statistics were found...
- Maximum elevation = 23.3 cm above sea level
- Minimum elevation = 6.6 cm above sea level
- Mode= 14 cm above sea level

These statistics show the wide range of elevation. the areas that were taken for the plain resulted in less sample values because of the extremely low elevation change. The mode shows that many of the areas was relatively high above sea level which could indicate thick lithosphere in the real world.

Conclusion

Gaining an understanding in sampling (in particular the systematic point sample method) both time and money can be saved. this was witnessed first hand during the collection of the data which lasted 4 hours.  To show even more detail, which might be needed, in areas of great elevation change the data points for that area can increase. The more data the more likely it will be accurately portrayed.  

Field Activity #3: Creation of a GIS for Hadleyville Cemetery using field data

Introduction 

The Hadleyville Cemetery is located in Eau Claire County off of County Road HH. This cemetery contains 120 lots with burials dated back to 1865 and is a total of 1.5 acres. The major challenge faced for the county is the lack of original records and maps of the cemetery. Other issues include the chemical weathering that has occurred to multiple gravestones, the removal of gravestones, and destruction to a large portion of multiple stones. Lack of identifying markings of grave sites is a major issue in the cemetery and creates a risk of disturbing a grave during a future burial. The overall goal of this project is to use various geospatial techniques to accurately map out the cemetery, particularly the occupied grave sites and create a detailed spreadsheet of important information regarding each grave.

The reason this will not just be a simple map or spreadsheet is because there is a lot of other information that should be known regarding the graves. Information can be stored in GIS and tied to a specific location and feature (in this case the feature is the grave sites) and used by management of the cemetery. This information will help in record keeping and buying and selling of plots within the Hadleyville Cemetery. As mentioned, the issues with the cemetery are mainly due to the lack of record and information about each grave. Applying attributes, such as name, date, and condition of gravestone will help solve this problem.

Information needed would be a highly accurate survey grade GPS system. The accuracy is important because the scale of the area is not very large and therefore accurate locations are critical to ensure that issues do not arise (such as the buying and selling of occupied graves or the accidental exhumation of a body). GPS combined with the study of aerial imagery of the area will allow the gravestones and obvious graves to be accurately mapped. As mentioned, a major issue is the absence or destruction of headstones.

Overall, the objective of using GPS along with aerial imagery would be to georeference the aerial image and locate the grave sites based on the image. Using the GPS, we would then be able to just upload the points into GIS and not have to manually place the grave site locations.

Study Area

As mentioned, the Hadleyville Cemetery is located in the city of Eleva, just south of Eau Claire, off of County Road HH (Figure 1). Overall, the cemetery has been maintained except the issue of the destruction of gravestones. This allowed for adequate data collection with the UAV imagery. The data was collected in the late summer and therefore the southwest and southeast corner of the cemetery has a large canopy covering several gravestones. This would not have been as much of an issue if the data was collected in the late fall but that was not the case. Initially the data was collected around 3:00pm which led to a large amount of shadow cast by the gravestone and surrounding trees. Data was then collected around noon the second time. This imagery was used in the map-making process. 

Figure 1: Hadleyville Cemetery location

Methods

As a class, we used various geospatial tools to mark the locations of grave sites. These tools include a survey grade GPS to pinpoint the exact location of the grave sites within the cemetery which allows for precise locations. Another tool used was a UAS (unmanned aerial system) drone. With this technology, the entirety of the cemetery was imaged. The accuracy of the GPS unit was very important due to the small area in question. However, the time allotted to data collection was limited and therefore created an issue. To solve this issue, a UAS was used to capture imagery of the cemetery. Other information necessary to create an accurate database was collected as well. Before collecting data in the field, a set of attributes for each grave site was determined. As a class, these attributes were put into a normalized excel sheet (figure2). The data was collected on pen and paper because it was more efficient. Information collected about the cemetery included first and foremost whether or not the grave stone was legible. Depending on the answer, the rest of the information was collect. This data included last and first name along with a middle initial,  year of birth and year of death, if the statue was standing (if left blank it indicates that the stone was flat and in the ground purposefully), type of stone (marker type), whether is was a joint tombstone and number of people, and finally any additional notes. The PointID field was determined based on the layout which is explained further on.  This data was then uploaded into an excel sheet on GoogleDocs. By putting these attributes into an excel a potential table join could be made within ArcMap. This means that all of the class data was formatted the same. While in the field, the cemetery was split up into lines in order to ensure that all areas were collected(Figure 3).

Figure 2: Excel sheet showing the normalized data collected by class

Figure 3: Hadleyville class grid pattern

Using ArcMap, the aerial imagery was manually analyzed and each grave was digitized. To do so, the Hadleyville imagery was uploaded to a geodatabase within ArcMap. The geodatabase, jackiecemetery, was a file geodatabase created for this project only. After the Phantom image (RGB bands 3,2,1) was imported, digitizing of the gravestones had to be done. Creating a new feature class within the geodatabase allowed for a new layer to be created and edited. The feature class, Graves, was added to the geodatabase and given the same projection as the image was uploaded with and editing began. The feature type selected was point. Within each point, two fields were created. One field was the PointID (text type) and the second was Image (raster type). The PointID for each grave had to match the PointID within the excel spreadsheet. By doing so, a table join was created and all of the other information regarding the specific graves were added to the attribute table within ArcMap. This saved time by uploading the information at once rather than each field by each grave. Also seen in the image was ground control points. These had to be digitized as well to ensure no confusion by viewers. The same process was followed.

Results/Discussion

The newly formatted data allowed for a table join which saved a lot of time in the map-making process within ArcMap. Performing a table join resulted in all of the data within the excel sheet to be added as attributes within ArcMap. The table join conducted was done so by the use of the common field "PointID". The extra attribute created titled image portrays that there was an attachment of an raster. This field holds the image of the gravestone embedded in the map. 

Figure 4: Attribute table from ArcMap showing a table join was completed

The PointID attribute is important for both the location and the connected attributes. The following map was created to show the location of each grave stone (Map1). As seen, the map closely resembles figure3 which can be found in the methods.

Map 1: Indicates the PointID for each grave

Another important attribute was the Last Name. this is important to know when dealing with families wanting to be buried together. Map 2 shows the last name of the individual buried at each specific grave site. As seen, many families have already began to be laid to rest in clusters together. 

Map 2: Map showing the last names of the individuals buried at each location

In many cases, the amount of individuals within a certain cemetery is misinterpreted based on the number of tombstones that are visual. However, with high costs for tombstones, it is becoming more popular to share on tombstone for several people. This not only ensures that the individuals are buried near each other but it also saves surface space within the cemetery and leaves room for more family members to be buried nearby as well. Map 3 indicates the 

Map 3: Map showing the location of the joint tombstones

Despite the success of the maps and the table join, there are many possible errors that may have occurred. For starters, human error is often likely when the work is split up. At the beginning of the project the class was at a loss on how to begin, how to split the cemetery into sections and label them. In the end, data was collected for the same graves several times and had to be filtered out. Another possible error occurs where there are tree coverage. The placement of the graves are estimates of the actual location. This can cause issues in the future because of the importance on the accurate locations of all of the graves. Discussing how to enter the project and set up data should have been determined prior to heading into the field which would have saved the step and stress of then figuring out all of the notes later on after familiarity of the project decreased. The issue regarding the survey grade GPS should have been thought of prior to wasting large amounts of the data collection time trying to 1)figure out the system though the experience was useful and 2) triangulate under cover. Several members of the class ended up having to return to the site to collect the remaining needed data.

Conclusion

The methods of this project allow for the completion of an accurate map containing pertinent information regarding the cemetery. through the use of GIS, GPS, and aerial imagery locations of grave sites can be mapped. This work can help future management of the cemetery and provide historic record of the area. Because the class collaborated, the majority of us had a similar format for how to collect data. However, there was a large amount of frustration toward the beginning while deciding the best way to go about note taking and formatting. Overall, the project provided the cemetery management with accurate location and information necessary for the cemetery records. The location of the grave stones are highly accurate and should provide valid coordinates of  inhabited graves. 

Field Activity #2: Hadleyville Cemetery Data Collection

 Introduction

Provide background to the problem at hand. What are the problems and challenges facing Hadlyville cemetery?
        The Hadleyville Cemetery is located in Eau Claire County off of County Road HH (Figure 1). This cemetery contains 120 lots with burials dated back to 1865 and is a total of 1.5 acres. The major challenge faced for the county is the lack of original records and maps of the cemetery. Other issues include the chemical weathering that has occurred to multiple gravestones, the removal of gravestones, and destruction to a large portion of multiple stones. Lack of identifying markings of grave sites is a major issue in the cemetery and creates a risk of disturbing a grave during a future burial. The overall goal of this project is to use various geospatial techniques to accurately map out the cemetery, particularly the occupied grave sites and create a detailed spreadsheet of important information regarding each grave.

Figure 1: Hadleyville Cemetery; located South of the City of  Eau Claire, Wisconsin

Why is building a GIS of this project better than a simple map and/or spreadsheet?
 The reason this will not just be a simple map or spreadsheet is because there is a lot of other information that should be known regarding the graves. Information can be stored in GIS and tied to a specific location and feature (in this case the feature is the grave sites) and used by management of the cemetery. This information will help in record keeping and buying and selling of plots within the Hadleyville Cemetery
What equipment are you going to use to gather the data needed to construct the GIS; ie what is the     overall approach?
  Information needed would be a highly accurate survey grade GPS system. The accuracy is important because the scale of the area is not very large and therefore accurate locations are critical to ensure that issues do not arise (such as the buying and selling of occupied graves or the accidental exhumation of a body). GPS combined with the study of aerial imagery of the area will allow the gravestones and  obvious graves to be accurately mapped. As mentioned, a major issue is the absence or destruction of headstones.

What are the overall objectives of the method being employed to gather the data.
Overall, the objective of using GPS along with aerial imagery would be to georeference the aerial image and locate the gravesites based on the image. Using the GPS, we would then be able to just upload the points into GIS and not have to manually place the grave site locations.

 Methods

What combination of geospatial tools did the class to use in order to conduct the survey? Why?
              As a class, we used various geospatial tools to mark the locations of grave sites. These tools include a survey grade GPS to pinpoint the exact location of the grave sites within the cemetery. This allows for precise locations. Another tool used was a UAS (unmanned aerial system) drone. With this technology, the entirety of the cemetery was imaged. This allows for the class to manually analyze the image and mark the location of each grave. Further on in the project the use of GIS will be necessary to georeference the image and upload supplemental imagery and information regarding each grave site.

What is the accuracy of the equipment you are intending to use? (Be sure to cover each piece of equipment)
               The accuracy of the GPS unit, as mentioned, is very important because with such a small area in question the bigger the consequences of an error in location.
               It will be important to get multiple imagery of the area from as far back as possible (at least 1865). This is important because it will be up to date and many stones will be destroyed at this point in time.

How was data recorded? List the different methods and state why a pure digital approach is not always best. What media types are being used for data collection? Formats?
                 Data was collected and recorded both digitally and manually. For the digital aspect, the survey grade GPS system used allowed us to input various attributes regarding each site and also attach a  picture of the stone. Attributes included in the data collection process include if the grave stone was readable, the birth and death date listed on the stone, and finally the name of the individual buried a that location. This was very important to have. Manually, much of the class went through and took detailed notes about the following along with a picture to match each grave. This worked much faster than the survey grade GPS system because we did not have to wait on location to be marked.

How will you transfer the data you gather into a GIS
              Data will be transferred from the GPS unit to ArcMap through a USB port. The additional information will have to be added as an attribute under various fields. This, together, will create an accurate map of the area.
What equipment failures occurred if any? What was done to remedy the situation?
            There were several issues that occurred while using the survey grade GPS system. While a section or two of the cemetery was under tree coverage, the system had a hard time pinpointing the location and communicating with the satellites. This caused a large time issue because only 10 or so grave stones were collected in the 3 hours the class was there. Out of over 50 grave sites, we did not get very far in the cemetery. To fix this issue, the class decided to manually take notes and analyze the aerial imagery to find the locations of the stones.

What might have been done to facilitate data collection in terms of equipment and refining the method?
             In retrospect, it might have been better to only work on the sites out in the open that did not have any tree coverage. This would have made the GPS software a lot more efficient and the overall project move more fluidly. For the stones under the tree the use of manual note taking and pictures would have worked much better.

 Conclusion

How did the methods transfer to the overall objectives of the project?
             The methods of this project allow for the completion of an accurate map containing pertinent information regarding the cemetery. through the use of GIS, GPS, and aerial imagery locations of grave sites can be mapped. This work can help future management of the cemetery and provide historic record of the area.
How did the mixed formats of data collection relate to the accuracy and expediency of the survey?
              Because the class collaborated, the majority of us had a similar format for how to collect data. However, there was a large amount of frustration toward the beginning while deciding the best way to go about note taking and formatting.
Describe the overall success of the survey, and speculate on the outcome of the data.
               Due to the issues with the survey grade GPS a majority of the cemetery still needs to be marked and noted. The attributes of these sites are important for the later records of the cemetery and can help aid the management determine open and closed grave sites.

Field Activity #1: Hadleyville Cemetery Mapping Proposal

Introduction

o Provide background to the problem at hand. What are the problems and challenges facing Hadleyville cemetery?
           The Hadleyville Cemetery is located in Eau Claire County off of County Road HH (Figure 1). This cemetery contains 120 lots with burials dated back to 1865 and is a total of 1.5 acres. The major challenge faced for the county is the lack of original records and maps of the cemetery. Other issues include the chemical weathering that has occurred to multiple gravestones, the removal of gravestones, and destruction to a large portion of multiple stones. Lack of identifying markings of grave sites is a major issue in the cemetery and creates a risk of disturbing a grave during a future burial. The overall goal of this project is to use various geospatial techniques to accurately map out the cemetery, particularly the occupied grave sites and create a detailed spreadsheet of important information regarding each grave.

Figure 1: Hadleyville Cemetery; located South of the City of  Eau Claire, Wisconsin

o Why is the loss of original maps and records a particular challenge for this project?
             The lack of original records and maps of the Hadleyville Cemetery is the most prominent challenge for this project because their is no background information that can be used as a reference throughout the project. This also creates an issue because with time, many stones experience weathering, destruction, or human disturbances. Where there used to be a headstone, there may not be anything left of it and it may seem like an empty plot. With little knowledge regarding the cemetery, it is very important that this map be as accurate as possible in order to preserve the community history, identify graves, and confirm the absence of a grave site for future purchase.

o How will GIS provide a solution to this problem?
             One of the many solutions for this problem would be the use of geographic information system (GIS). This technology allows you to map locations. Headstones and possible grave sites can be located with a GPS and put into a map to visualize the cemetery. Using GIS, users are also able to add specific attributes or further information about a specific feature and not just the location.

o What makes this a GIS project, and not a simple map?
             The reason this will not just be a simple map is because there is a lot of other information that should be known regarding the graves. This information can be stored in GIS and tied to a specific location and feature (grave sites) and used by management of the cemetery. This information will help in record keeping and buying and selling of plots within the Hadleyville Cemetery

o What equipment are you going to use to gather the data needed to construct the GIS?
               Information needed would be a highly accurate GPS system. The accuracy is important because the scale of the area is not very large and therefore accurate locations are critical to ensure that issues do not arise (such as the buying and selling of occupied graves). GPS combined
with the study of aerial imagery of the area will allow the gravestones and  obvious graves to be accurately mapped. As mentioned, a major issue is the absence or destruction of headstones. A possible solution and method to be used to detect a grave is the use of ground penetrating radar (GPR). GPR is a noninvasive geophysical method that uses electromagnetic waves to detect subsurface features. Professor Harry Jol, at the University of Wisconsin- Eau Claire, is an expert in GPR. This method has been used to uncover ancient churches, synagogues, detect pipelines, and much more. With this technology it would be simple to map out subsurface feature and determine which would be a grave or not.

o What are the overall objectives of your proposal?
              Objectives of this project include learning to use GPS and coordinate systems to accurately plot grave sites, use aerial imagery to determine headstones, and possible use GPR to create a map with a set of attributes attached to each location with important information regarding each grave.

Methods

o What is the sampling technique you chose to use? Why?
               The sampling technique used for this project will be pragmatic because data collection will be done through practical reasoning. Where there is gravestone, a point will be collected. The idea of how most cemeteries are set up can help determine probable locations of gravesites.
               
o What is the accuracy of the equipment you are intending to use? (Be sure to cover each piece of equipment)
               The accuracy of the GPS unit, as mentioned, is very important because with such a small area in question the bigger the consequences of an error in location.
               It will be important to get multiple imagery of the area from as far back as possible 9at least 1865). This is important because it will be up to date and many stones will be destroyed at this point in time.
               If using GPR, it would be important to use a high resolution GPR antennae (a 450 MHz) which does not penetrate as deep but has a much clearer image of what lies beneath. Because graves are no more than 6 feet below the surface, it would be manageable to image.

o How was the data entered/recorded? Why did you choose this data entry method?
              This portion is yet to be completed.
o How will you transfer the data you gather into a GIS
              Data will be transfered from the GPS unit to ArcMap through a USB port. The additional information will have to be added as an attribute under various fields. This, together, will create an accurate map of the area.
o What drawbacks are there to the method you propose? How to the pros outweigh the cons of this method?

            Drawbacks include the lack of information that will be available from the headstones. The weathering or destruction will greatly alter the ability to be read. Another drawback is the possibility of an inaccurate GPS system could greatly influence the outcome of the map and lead to issues in the future for management. However, with the technology provided by the university, the ability for the project to be completed accurately is very likely and outweigh the drawbacks.

Conclusion

  o How do your methods transfer to the overall objectives of your proposal?
              the methods of this project allow for the completion of an accurate map containing pertinent information regarding the cemetery. through the use of GIS, GPS, aerial imagery, and GPR, locations of gravesites can be mapped. This work can help future management of the cemetery and provide historic record of the area.