Geog 206
1. A data model is a set of regulations utilized in order to illustrate and represent features of the “real world” in a computer. The two most frequently used data models are Geometric/Geospatial Data and Attribute Data models.
2. Topology is the analysis of geometric properties, which do not alter even when the forms are twisted, stretched or experience related geometric transformations. Furthermore, it confines and records the relationship between features. Hence topology is important because it is new and more efficient, especially regarding processing, then for example Spaghetti Models, which are often times prone to redundancy, unwanted overlap and/or inaccurate analyses.
3. The raster data model would definitely be best for representing hillside slope given that it provides a more accurate representation of continuous data. Hillside slopes are surely an example of continuous data because one can find them in many different regions of the world.
4. The relationship between spatial detail and cell dimension with regard to raster models is: the bigger the cell, the lower the resolution and the less detail one can resolve. Therefore, cell resolution relates to its size on the ground, where every grid cell holds one value, even if it is in fact empty.
5. The four types of attribute data are first nominal data, which is descriptive and/or categorical data as for example race/ethnicity, which can be divided between Caucasian, African-American, Asian, ect. Then there is ordinal data that is ranked/ordered like it is often times in surveys, where 1=Strongly disagree; 2=Disagree; 3=Neutral; 4=Agree; 5=Strongly agree. Third, there is the interval data, which is ordered, yet with absolute differences in magnitude and arbitrary zero. A good example would be temperature in degrees Fahrenheit. Lastly, there is ratio that is ordered data, with absolute differences in magnitude and absolute zero as for instance a person’s weight.
6. Two types of vector data file formats are: shapefile and coverages.
7. Two types of raster data file formats are: grids and images (tiff, jpeg, etc.).
8. One can do all of the following in ArcCatalog EXCEPT, c.) Select features.
9. Yes, the World.mdb geodatabase contains four feature classes.
10. The names of the feature classes that are contained in the World.mdb geodatabase are: cities, countries, disapp_ area and world30.
11. The flight_path.lyr layers file references spatial data.
12. One way to add data to ArcMap is to drag it from ArcCatalog. When the data is there, one can look at it as a map display and table of contents. The other way to add date to an ArcMap document, when ArcCatalog is not open, is to use the Add Data button in ArcMap, which is located on the Standard toolbar.
13. There are 699 records in the dissap_area feature class. One can determine this by looking at the Attributes category under the dissap_area feature class in ArcCataalog.
14.
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