Lab 3: Creating a GIS for Hadleyville Cemetery

Introduction

All previous maps and records of this cemetery were lost, and government officials wish to preserve the community history through the production of a new map.  This project is a GIS project because of the complex nature of the information being collected.  While a simple map could display general plot location and plot names, using GIS allows more specific location information, complex attributes such as the condition of the stone (broken/whole/missing), as well as embedded pictures of the plots.  For this exercise, a drone and survey-grade GPS unit were used.

The purpose of this project is to design an accurate map of the Hadleyville Cemetery that will be useful to government officials.  Information concerning plot location, plot occupancy/vacancy, plot names, plot birth and death dates, and condition of the stone should be accessible and understandable to map readers.

Study Area

The study area for this exercise was Hadleyville Cemetery, a small cemetery located in Eleva, Wisconsin (see Figure 1).  The data was collected during two late afternoons in Fall 2016. 

Figure 1: Locator map showing study area relative to Wisconsin

Methods

Data was recorded both digitally and manually for this activity.  Aerial imagery data was acquired by flying a drone over the study area on two different days.  Data about the graves was collected with the survey-grade GPS unit and recorded digitally by entering attribute data on the handheld device and then attaching a picture of the headstone to this data.  Additionally, data recorded manually was done so by hand in field notebooks.  Some class members took notes regarding headstone condition, inscriptions, number of headstones in the rows, etc. while others took pictures of each stone. A pure digital approach is not always best when considering aspects such as time constraints.  For example, in this activity, the survey-grade GPS took way longer to collect data than the manual method. 

After all of the data was collected, it was transferred into a GIS for future use.  The aerial imagery was transferred using cables and a USB port.  Since the data collected by the survey-grade GPS was incomplete (only data about the first two rows was acquired), the class ended up only using manually collected data about the graves.  This manually collected data was typed by hand into a shared, online Google Docs document.  Before entering all of the data, the class decided upon a set number of attributes such as first name, last name, date of birth, date of death, notes, etc.  The class also agreed upon a system of common identifiers for each grave, dividing the cemetery into rows and columns and assigning each deceased person a unique ID.  

Results & Discussion

After each class member had entered their data into the shared Google Docs document, each student went about creating their own GIS and map of the cemetery.  After downloading the document as an Excel file and making sure all of the data was normalized, creation of the GIS could begin (see normalized table in Figure 2).  This involved setting up a geodatabase, importing the drone imagery, digitizing the graves and attaching attribute data through a table join.  The resulting map can be seen below (Figure 3).  Since the entire table was too large to provide in a single picture, it is accessible online here. 

Figure 2: Attribute table with data about graves; complete table available here

Figure 3: Map illustrating grave locations; full size map here

The data collection process could have been refined by developing a class plan before collecting data.  This may have involved developing a common grid system for note taking, as some of the students did.  Additionally, the GPS unit could have been used in the areas of the cemetery where there weren't any tree coverage problems, leaving the areas with shadows to be documented via manual note taking.  Sources of error include human error when recording data, illegibility of grave markers, and equipment failures.  

Conclusion

The methods transferred fairly well to the overall objectives of the project, enabling the class to more or less effectively gather the data needed to produce an accurate map of the cemetery. The mixed formats of data collection were beneficial in terms of accuracy and expediency of the survey.  After determining that the GPS unit was taking too long to acquire location information, the class was able to utilize other formats of data to fill in the blanks.  While the GPS unit only collected information about the first two rows, the class was able to manually record data about the entire cemetery. Aerial imagery was collected of the entire cemetery as well. 

While the class was able to gather data about many of the graves at Hadleyville Cemetery, there were still many unknowns.  For example, type of stone was not recorded for many plots.  Since each student collected data slightly differently, it was difficult to consolidate the data into a cohesive spreadsheet for all to use.  Despite this, the maps that the students in this Field Methods class created will be useful to government officials in providing basic information about the cemetery.  At the very least, if anyone wanted to created a more detailed and accurate map, they could follow the methodology outlined in this blog to do so.  Furthermore, the city could take this data and incorporate it into an online GIS platform, allowing photos to be integrated more easily.