Lab 4

  1. Do the points and lines represent the data with the same level of abstraction? Discuss in termsof their representation of the two data layers(cities, roads) that we have added so far, and interms of other types of data that they might represent.

When a point is used to represent a city, the many roads and buildings that make it up are lost. When a line is used to represent a road, very little is lost.

  1. What happens when you use the identify tool? Is the option to change the layer(s) beingidentified useful?

The identify tool allows for searching of the geographic dataset by location rather than attribute. For example, clicking on a city with the identify tool brings up the name and any other data associated with that city (population demographics, area, etc.). The option to change which layer is being identified is very helpful considering the level of overlap of layers.

  1. Why do you think the Field Definition requires that you differentiate between text and numericdata types? Why do you need to specify the field width?

Most types of data manipulation are possible with only one type of data. When the width of the field is specified, the program designates space on the hard disk for the entire table based on the size of the individual fields.

  1. What has changed in the table after joining?

The weather data is now present as a column in the attribute table for “states”. Most states have null values, since only data was only generated for ten states.

  1. How is the original attribute data from the States layer distinguished from the Weather data that you joined?

A second OID column is present at the start of the weather data, separating it from the rest of the states layer.

  1. What would happen if you tried to join the attributes from the States layer to the Weather data (rather than joining the Weather data to the States data as you just did)?

All of the states data that did not match with the 10 states in the weather table would be lost, and it is likely that the map would not display as such.

  1. Print screen of selected record

  1. Print screen of new attribute table

PART 2

  1. What does the reclassification step in Step 1 accomplish?

By reclassifying the data, we defined the number of categories and the range of data that would go into each. We then labeled each of these categories based on a predetermined scale. This resulted in an overall easier map to read.

  1. Please include a JPEG of roadscore (end of Step 1). This should be a completed map (i.e. ready for display), exported into your student folder, and inserted as a picture into lab report.
  1. Please include a JPEG of hydroscore (end of Step 2). This should be a completed map (i.e. ready for display), exported into your student folder, and inserted as a picture into lab report.

  1. At the end of Step 3, what does the map tell you in terms of the developer’s office building project? What do the highest scores represent? What do the lowest scores represent?

The highest scores represent desirable locations in terms of distance from roads and streams. These areas are not close enough to streams to be flood-prone, and close to major roads, enabling easy access by car or truck.

  1. What does Step 4 accomplish towards producing the final suitability data layer?

Step four adds what is in some ways the most important measure of suitability: zoning. Certain types of businesses are only allowed in certain zones, so there is no point in finding a desirable site for construction outside of the right zone.

  1. Please include a JPEG of final suitability layer (end of Step 4). This should be a completed map (i.e. ready for display), exported into your student folder, and inserted as a picture into lab report.
  1. Prepare a brief executive summary (~2 paragraphs) to the developer, summarizing your results. Include a short description of the analysis you performed and indicate the locations you think would be the best choices for her office project.

In order to determine the most suitable locations for your office building, we first created a map that rated areas of Chapel Hill from one to ten based on distance from major roads. We then combined this map with a similar map that rated distance from streams. The resulting map showed areas rated on a scale from two to twenty, with twenty being the areas closest to major roads and farthest from streams. The final step involved removing any areas that were not zoned for Office/Industrial use.

The resulting graph has a scale from 0 to twenty, where zero values represent unsuitable zoning. As is visible on the map above, there are many areas that rank at or near 20 on the suitability rating. Which of these areas you choose will depend largely on what type of business you plan to run and where you expect most of your employees to commute from. For example, if you expect many workers to commute from Raleigh, Durham, or elsewhere, a location in the upper right hand side of the map, near I-40, would be especially desirable. On the other hand, if you expect to fill positions locally, a location near airport road or even in downtown chapel hill would be better.