Field Activity 1, Terrain Creation and Survey

Introduction

In this field activity, we were divided into groups to accomplish two main objectives.

• Create a three dimensional terrain using garden planters.
• Survey this terrain to collect information on elevation that will be used for mapping.

Additional requirements in completing this activity were

• The terrain should include a hill, valley, ridge, depression, and plain.
• The survey should be recorded into an excel document with X,Y, and Z coordinates to be later imported into ArcGIS.

We had a fair amount of flexibility in this activity, being able to decide when, and how to build our terrain and complete our survey.  A large purpose of this activity was to work on critical thinking skills, and practice working together as a team.


Methods

Our methodology was largely based of the work of previous groups who did this activity.  We read over some of their blog posts and made several decisions about how we would go about this activity including

• The border of the garden planter would be the baseline, all of our terrain would exist below this line so that all of our Z coordinates would be negative, and easier to record.
• We would make a grid using thumbtacks and yarn, and the grid would be 10cm x 10cm (we saw groups that did smaller grid cell sizes report that it made the survey very tedious). 

Our group met on Friday January 30th at 11:00 AM to create the terrain and take the survey.  Weather conditions were overcast, -9°C, with southwest winds at 3mph.  We used snow to create the terrain, making sure to keep all of the features below the edge of the garden, so that all of the elevation data we collected would be negative.



Photo 1.  Creating the terrain




Photo 2. Completed terrain

  Our next step was to create a grid with a coordinate system to survey the elevation.  We placed thumbtacks on the edge of the garden planter every ten centimeters, we decided we would disregard the last row of cells on the edge of the planter that were less that 10 centimeters so that we could keep our surveying consistent for all of the cells.  Our next step was to use the yarn to make a visible grid out of the thumbtacks.  Unfortunately we ran out of yarn, so we improvised, using a combination of yarn and measuring sticks in order to see the grids that we were surveying.  This method was not ideal, but it worked with what we had available at the time.  For each grid cell we took an elevation measurement at the center of the cell.  We also had a diagram of the planter with the grid drawn in, so that we could reference the X and Y location of surveyed point as well.



Photo 3.  Improvised survey methods, for collecting data on elevation

We wrote down the Z coordinates on a piece of paper with a grid.  A picture of the original document is shown below.

Photo 4. Copy of field notes

 
The XYZ coordinates are shown in the photo below




Photo 5.  XYZ coordinates

Discussion

Despite some minor setbacks in the actual creation of a grid, our group was able to complete an elevation survey of the terrain we had made within approximately an hour.  Our group was successful in communicating with each other, and working towards a solution for the problems we faced.  Being able to critically think and work together was essential in collecting the data.

There were a couple of concerns that I had when collecting the data

• Whether the 10cmX10cm grid cell will give detailed enough information for the next activity.
• Whether our improvised methods will lower the quality of our data.

For each of the concerns, viewing other blog posts increased the confidence that I have that our collected data will be accurate and detailed enough for the next activity.  Our methodology matched closely with the methodology of other groups.  The 10X10 cm grid cell seemed to be a decent grid size that other groups chose.  A 5x5 grid cell would have given us more information, but it would have also been tedious work surveying all of the points and transferring it into an excel document. Other groups also dealt with an incomplete physical grid due to lack of yarn, and mention any concerns with the quality of their data.

We could have gotten more detailed information, and taken more precise measurements (rounding to the nearest half centimeter instead of the nearest whole centimeter), but for the most part I think that we did collect good enough data, and that we did so in an efficient manner.  The best way to evaluate our data will be in the next exercise when we create the DEM.  However, I think that our data will be accurate enough to make a good model.

Conclusion

The activity gave as practice with collaborative data collection, and critical thinking while solving problems.  The ability to choose our own methodologies made the project more challenging, but also gave us flexibility.  Our group was able to successfully work together to accomplish the objectives given in the assignment.  We produced a terrain with the necessary features, and we took a survey of this terrain to give us coordinates that can be used in the next exercise.  I found the lab useful, and thought that it was a good way to demonstrate what issues to be concerned with while collecting data for a project.