 | GIS |
1. Essay Questions
Limit each essay to two double-spaced typewritten pages plus references.
Most GIS are static systems. To what extent is this the result of the data sources that are available for database creation?
Given recent advances in GIS technology, to what extent is debate about the relative advantages of vector and raster formats an irrelevancy?
To what extent do proprietary data base structures limit the exchange of GIS data? Consider, for example, the difficulties of transferring data among ARC/INFO, GFIS, Atlas GIS.
Despite their errors, why are the 1990 TIGER files a major advance for GIS?
In assembling a municipal multi-purpose cadastre, how will the wide variety of data sources employed affect the accuracy of the combined database?
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2. Short Answer
Limit your answers to no more than 100 words.
What is the purpose of the Spatial Data Transfer Standard (SDTS) and how might it affect the development of GIS in the U.S.?
Why is correcting backup tapes for large databases an important consideration?
What is the smallest unit of aggregation used to report data from the 1990 US Census?
Distinguish among DLG, DEM, and DOQ formats developed by the US Geological Survey?
What are three important considerations in checking the pedigree of quality of digital data sources?
Why were TIGER files developed?
Why was the Spatial Data Transfer Standard developed? What are its major limitations?
GIS databases can be viewed as "abstractions, representations, or models" of reality. Apart from location, what are three of the several types of real-world relationships or properties that can be represented in such databases?
Topology or connectivity Functional relationships, say the dependency of check dams, gates, and drains in an irrigation system
Logical relationships, say where one phenomenon can only be added or changed if a certain condition holds true.
Others: proximity-neighborhood; Boolean spatial and attribute relationships
What is the principal advantage of an "object-oriented" database?
Object-oriented databases store information in ways that more closely mirror the real-world phenomena with which users are familiar. They can store and retrieve information about an entire object (such as a road, house, or stream) without searching for it by its intrinsic attributes.
No matter how inexpensive and wide-spread GPS technology becomes, why will it not entirely solve the problem of creating precise and accurate GIS datasets?
Define and explain the term "metadata."
What is the significance of the phrase" truth in labeling" as applied to GIS datasets?
According to William E.Huxhold (1991) in Chapter 1An Introduction to Urban Geographic Information Systems, what are two advantages of "data-base management systems" over their "transaction-based" counterparts?
How does the organization of hierarchical data files differ from the organization of relational data files?
Hierarchical files are grouped in a strict structural (parent-child) relationship to a master file (of IDs, for example). One file leads to another on the basis of relationships pre-programmed into the database using the master ID. Relational files are organized flexibly in terms of relationships between data shared by any two or more files.
What is the principal disadvantage of using "flat" files to store attribute information?
Flat files can waste much space since every data record must "carry" the same number of fields regardless of whether they are used.
This is a particular problem in large files containing a wide range of geographic entities that don''t all use the same data fields. Many redundant (empty) fields (or "cells") must be maintained in the database, wasting space.
Explain the difference between attribute data and cartographic data and give an example of each.
List three problems that arise in the management of very large GIS databases that are far less important for smaller projects?
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3. Multiple-choice questions
Choose the best or most appropriate answer(s) to the question.
What lessons were learned from the CORINE project?
GIS is still unsuited to regional environmental monitoring.
The quality of data sources is of prime importance in assembling international GIS datasets.
Map coverage varies radically by country, even in the developed world.
High quality environmental data is available for developed countries, but is time consuming to convert to digital format.
Which of the following are examples of non-spatial data?
The number of rooms in an office building.
The path of a highway between two cities.
The total population of Austin, Texas.
The intersection of two streets.
The site of the Lincoln Memorial in Washington, DC.
The 14th US Congressional District.
Which of the following are not characteristics of data quality?
completeness
attribute accuracy
coordinate jurisdiction
positional accuracy
timeliness
logical consistency
the size-shape ratio of irregular polygons
During database development, locational information may be input into a GIS using the following techniques:
photogrammetric digitizing
manual digitizing
standardizing geographic naming conventions
typing coordinates at a keyboard
adding map annotations to mylar map overlays
creating data directories
