Exam 1 Essay Questions Part 2



One of the most frustrating, but prevalent, problems in discussion of information technologies generally, and geospatial ones specifically, is the wide range of terms used by different writers to describe the same or very similar things. Starting with the following terms provide as many terms that are used to mean the same or very nearly the same as each of these (and be aware of others!):

record, line, arc, attribute, entity, entity type, area, coverage
 

Create a ER diagram that shows the structure of the parcel data that was used in the earlier normalization exercise. Show the ER for the normalized structure you created.

Bernhardsen provides a well conceptualized approach to conceptual data base design. Present the nine "steps" in the procedure and a brief (brief) statement as to what each involves.

Draw a small (Small - just a couple or three simple polygons!!) example of two polygon maps. Place solid circles where there are nodes and open circles where there are "shape points" or vertices, label arcs and areas/polygons. Overlay the two maps and place solid circles where there are nodes and open circles where there are "shape points" or vertices in the resulting, label arcs and areas/polygons. Part 2: Create two small attribute tables that have some attributes for each polygon. Show the resulting tables that are generated by the operation. Part 3: Assuming that this is a georelational database show the various tables (populate just enough records in each to make the point) BEFORE the overaly and after. Whew!

With two small sketch maps show how polygon boundaries that may be similar but not exactly corresponding may lead to slivers and other errors. Discuss the ways in which this problem may be eliminated/reduced by actions taken BEFORE a map overlay or by operations performed AFTER the overlay.

There are a set of polygon overlay operations in the ArcView geoprocesing wizard list these and indicate which GeoMedia operation would be used to obtain the same geometric result.

What are the GeoMedia steps necessary to create the following DIFFERENT buffer results - given a single polygon called "city" where the boundary of the polygon is the city limits:

    1. create a polygon that includes all of the city and areas within 5 miles of it
    2. create a polygon that is all portions of the city that are five miles or greater from the city limits
    3. create a polygon that is all the area from the city limits out five miles.
In the graphic http://www.ncgia.ucsb.edu:80/education/curricula/giscc/units/u186/figures/figure1.gif there are sixteen possible combinations. You should be prepared to identify which areas would result from these different logical operators.