Arc GIS

Arc GIS

ArcView, or ArcGIS, is a Geographic Information System program that was used in 2008 by the Mapping Team students to store, analyze, and manage collected data. This data was presented on a map and was used as an easy visual representation. The team used an aerial photo of Monwabisi Park provided by the city, and digitized information collected by the students and resources, such as the Water & Sanitation Department, onto the image. This process takes time to execute, and without a strong understanding of the software, can be extremely difficult to master. The 2009 Planning Team used ArcView in a similar manner as the 2008 team. Because ArcGIS has a significant learning curve, the information below details how to use the program in an effort to aid students in the years to come.

Within ArcView, there are two programs that were used together to complete the maps. One is ArcMap and the other is ArcCatalog. ArcMap is where all the data is stored and where all the data can be accessed. It is where the original aerial photo is located and where the overlying data is organized. Since the data collected in the past year had been displayed in ArcMap originally, it can now be opened and utilized in the future on ArcMap by performing a few simple steps, as seen below. ArcCatalog is used to create the different shapefiles that are represented on the aerial photo in ArcMap. These shapefiles can represent three different types of data. First is a point, which represents a specific location, such as an address. The second is a line, which represents an area boundary, such as a contour line. The third is a polygon, which represents an area with similar characteristics, such as an area of land that was once a landfill. Once the data is created in ArcCatalog, it can then be managed and displayed in ArcMap. The following information includes steps taken by the 2009 Planning Team in order to open existing files, create new data onto the existing files, and edit and manage the data.

Opening the Monwabisi Park GIS Files

Figure 1

Figure 1

 

 

  1. Open ArcMap with a new template.
  2. Open aerial map with existing data (shapefiles and layers) from external hard drive in the GIS 2008 file (Figure 1).
    1. The main ArcMap file is called Monwabisi Park – WPI
  3. The shapefiles may not appear at first because they could be saved in different folders. In order to display these files, you must locate them on the hard drive.
    1. Click on the box next to the file which does not appear. There will be a red exclamation point also next to the box.
    2. An “Open” window will appear. Locate and open the file from the hard drive. You may have to connect to the hard drive first.
    3. Make sure all of the shapefiles are located and are open.
  4. Save all of the files (Monwabisi Park – WPI and all corresponding shape files) into one folder. This will allow all files to appear when the aerial photo is opened, and will prevent having to locate them again.

The files that were created in 2008 include locations of proposed roads, water taps and toilets, lighting fixtures, shebeens, redevelopment seeds, bus stops, etc. This year, we have collected a significant amount of new data to add on to last year’s.

Adding New Data

  1. Open ArcCatalog along with the Monwabisi Park – WPI file on ArcMap.
  2. Open the GIS 2008 file (all existing data and Monwabisi Park – WPI file) into ArcCatalog.
  3. Choose an existing shapefile layer that you would like to add to. For example, if you want to add in the water pipeline, you would choose the water & sanitation layer.
    1. Right click that chosen layer
    2. Click New – Shapefile (Figure 2)
    3. Name the new file and choose the type of file (dot, line, polygon).
    4. Edit the coordinate system by importing one off of an existing file. Under Spatial Reference in the “Create New Shapefile” window, click Edit, then Import, then specific file. Make sure the file chosen matches the coordinate system of the aerial photo (LO 19).
    5. Click apply. This new file will appear under the specified layer.
  4. Click on the newly created file and drag to the ArcMap.
  5. In ArcMap, start digitizing the new data by right-clicking on an existing tool bar and selecting the Editor tool bar.
    1. Click start editing
    2. Click the folder in which you had just added the new shapefile (Figure 3).
    3. Click Ok, then start editing.
    4. Make sure the first drop down bar in the Editor toolbar is set to “Create New Feature”.
    5. Choose the correct target (the new layer you had just created in ArcCatalog) in the second drop down bar.
    6. Click the pencil to draw the shapefile onto the aerial photo.
    7. Once you are done digitizing information, click Save Edits, and then Stop Editing in the Editor toolbar (Figure 4).



 

Figure 2

Figure 2

Figure 3

Figure 3

 

Figure 4

Figure 4

 

 

When data is collected by field observation or by having residents of Monwabisi Park locate certain things on a map, digitizing the information gathered in this method is relatively simple. It may take a long time if there are many points or lines, but it is very accurate. Once the data is recorded onto the map, it can then be managed and edited.

Editing Data

  • Changing data point shape/color/etc.
    • Double click on the point in the left column that you wish to change. There you can change all of the properties.
  • Edit layer or file properties
    • Right click on the file in the left column. Click on Properties at the bottom.
  • Label features
    • If a file has labels corresponding with it, such as contour lines and their measurements above sea level. Right Click on the file in the left column. Click on Label Features.
  • Deleting data
    • With Editor tool bar, click on the arrow in the toolbar, click specific data point, line, or polygon, and click delete on the keyboard. (Figure 5)
Figure 5

Figure 5

 

 

Arc GIS Data Available

As this data is contained in a very large file, our Arc GIS data is not available online. To request some or all of the information, please contact us at ctpc@wpi.edu.