Geographic Information Systems Flashcards
7 cards from real CEP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Geographic Information Systems flashcards as text
What is the main difference between a geographic coordinate system (GCS) and a projected coordinate system (PCS)?
Answer: GCS uses latitude/longitude on a sphere while PCS uses x/y coordinates on a flat plane
A GCS references locations on a curved earth surface using degrees of latitude and longitude, while a PCS uses mathematical transformations to represent those locations on a flat, two-dimensional surface.
An environmental planner uses GIS to merge two adjacent county-level datasets into a single seamless layer. Which operation achieves this?
Answer: Append
The Append operation combines multiple datasets of the same feature type into one output dataset, making it ideal for merging adjacent geographic areas.
Which interpolation method in GIS is considered an exact interpolator, meaning it honors all input data points exactly?
Answer: Spline
Spline interpolation is an exact interpolator that forces the surface to pass through all input data points while maintaining a smooth continuous surface.
In GIS-based environmental impact assessment, what does a viewshed analysis determine?
Answer: The area visible from one or more observer points based on terrain
Viewshed analysis uses a digital elevation model to calculate which areas can be seen from specified observer points, critical for assessing visual impacts of proposed projects.
What is the primary function of a spatial index in a GIS database?
Answer: To speed up spatial queries by organizing features by location
A spatial index organizes geographic features by their location, dramatically reducing query time when searching for features within a specific area.
Which GIS concept describes the minimum distance between two distinguishable features on a map, related to map scale and display resolution?
Answer: Minimum mapping unit
The minimum mapping unit (MMU) is the smallest feature that can be reliably represented at a given map scale, influencing decisions about what features to include in a dataset.
An environmental planner wants to model how pollutants spread from a point source across a watershed. Which GIS capability is most relevant?
Answer: Flow direction and accumulation analysis using DEM
Flow direction and accumulation analysis uses digital elevation models to trace the movement of water and associated pollutants across a landscape following terrain gradients.