Lab 1: Creation of a Digital Elevation Surface

Introduction: The task was to develop a ridge, hill, depression, valley, and plain in a standardize snow filled planter, whose area was 3.5 by 7.5 feet. The professor, Joe Hupy, asked of us students to construct some form of coordinate system and survey method in which to later be able to map our landscapes in digital form.

Methods: In our planter we developed a 12 cm by 12 cm grid using twine and tacks. The data was recorded on the basis of the grid itself (which was easily transformed into an Excel spreadsheet) and the data that we recorded was the depth of the landform in relation to the top of the planter. Numerically, if the landform touched the twine, the data was written as 0 cm and so on. When recording the data into Excel, we changed the otherwise negative data, into its positive inverse and once the data is mapped, we will transform it back to its original state. The purpose of us doing this was for ease of data entry. Similar to most scientific data collection, the data were measured in metric units, specifically centimeters.

(Figure 1) Our planter with the various landscapes. 

The recording of the data itself began at the bottom left portion of the planter and finished at the top right. It was a 10 by 20 square grid in total. 

(Figure 2) Aaron measuring out 12 cm increments and placing the tacks to hold the twine.

(Figure 3) A closer look at the measurement process. 

(Figure 4) The basis of our 12 cm X 12 cm coordinate system.

(Figure 5) Measuring the z-coordinates with the ruler. The single vertical twine was moved for every column of measurement taken.

Discussion: As we did the creation of the landforms and the data collection in one day, there was no evidence of any change in the data due to weather conditions. However, there could have been errors in that in data collection, the person measuring could have sunken the measuring stick into the snow, creating a slighter deeper appearing landform in some locations. As a note, we ran out of having enough twine to be able to completely cover the planter with a grid. It was nearly complete running the long way except for the last line, in which we had to estimate the distance from the second to last twine over to the planter. For the long length, we moved a single piece of twine along the preset tacks after every row was complete, therefore still ensuring accuracy.

In addition, we tried to create an even plane to serve as the bottom of our model, but due to weather conditions and lack of tools it is likely that this surface was not even, thereby reducing the accuracy of the measurements.

Conclusion: Having this lab as an introduction to the course sets the mood in which a) the conditions are not always going to be the most pleasant which means that one should thoroughly develop a plan of surveying prior to the actual data collection and b) being thorough is key to being successful. Having this lab as the basis of the course will only help to get my mind in the process mode of geographic methods. I look forward to having a way in which I can see a problem, develop an accurate methodology in which to conduct the test and consider it overall with a scientific approach.