GIS 4035 - Module 3 - Land Cover and Area Classification

Process Summary Details

Exercise 1:

For this exercise, in addition to documenting your technical procedures, make note of your thought process in deciding where you draw boundaries and how you identify features. Your interpretation of the photograph is much more important than which tools you use to draw the map. That said, (1) your technical steps are still important, and (2) you do not need to record your processes for each and every polygon you create. Try taking notes on at least one of each type of LULC, as well as on features that are especially note-worthy or difficult to identify.

NOTES:

1.      When drawing polygons around the features, I wanted to select areas that would be large enough to be legible in the exported JPEG file. I did my best to interpret areas based on shape, and size, shadow and pattern of surrounding features. Because the list of criteria is vast (even at level II) I did not spend a whole lot of time distinguishing between what may be a river, and what may be a canal.

2.      I created the LULC shapefile, imported it to the table of contents and began creating features.

3.      I began by using the draw tool to create a polygon around large bodies of water. I followed this up with drawing polygons around bare land masses on surrounded by water. I opened the attribute table, and added two columns according to the directions. With each new polygon drawn, I would assign the appropriate code as well as a code description.

4.      When the entire map was completed, I right clicked on my shapefile in the table of contents, and selected properties. Then, I modified the key to all my features and selected a color scheme. After creating a map legend, the Code as well as the Code_Dscr fields would become apparent.

5.      I added the essential map elements to my map, and changed a few characters to make the map legend a little more aesthetic. I saved the map, and exported the JPEG file like last time.

Q: List all of your LULC codes, Code_Descr, and a full description of what each is, what features are included in it, why you decided to classify it as such, etc.

A: The codes and code descriptions I used for the module are as follows:

11- Residential: Much of the map was marked as a single large feature shaded in yellow. Residential land was roughly recognized by the pattern of what seems to be houses, lots of small side streets and sparse vegetation that seems more aesthetically dispersed than natural.

12- Commercial Services: The polygons that fit this criteria were selected based on the proximity to a highway, and the size of parking lots. They seem to fall close to residential areas and are easily accessed from bigger roads.

122- School: There are only two polygons present under this category. They are shaded in orange, and both fall on the right side of the major road feature. The features were determined to be schools based on the size and shape of the building, and the parking lots. Also, the driveway designed for school buses is very easy to tell on an aerial photograph.

13- Industrial: The polygons that were placed under this criteria, had the look of industrial parks or construction areas from the top. It was generally the size as well as the appearance of the smaller features contained within, that lead to this classification.

15- Commercial/Industrial Mix: Only a single polygon falls under this category, and it is mostly due to the proximity to another large industrial feature.

41- Deciduous Forest Land: Determined by the color of the trees in largely overgrown areas. There are two features along the shore which seem to fit the category, as well as three more which are deeper inland.

43- Mixed Forest Land: Only a single feature falls into this category. Mostly due to the context, and its proximity to a lake where I would expect a mixed variation in trees and brush.

51- Streams and Canals: Used to define the body of water to the left side of the map, mostly due to its many offshoots which cut around the islands. The body of water is very large when compared to features like residential properties, but it was much more convenient and consistent to throw the entire area into the same category instead of splitting it up more specifically.

52- Lakes: There are two very small lakes, easily distinguished by shape, uniformity of color and by their proximity to tree cover all around them. They seem to be exceptionally small, and could have been interpreted to be ponds as well, but I would expect denser vegetation when mapping a pond.

621- Marsh: The marsh category was applied to everything on the map, that is located close to a body of water and has a difficult to distinguish type of vegetation. Most on the marshes marked fall on the left side of the map, along the large river. Some of them, also fall on the shore of the mainland.