Geographic Information Systems Flashcards
7 cards from real SAF 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
When using GIS to support a forest management plan, which type of analysis identifies areas where multiple constraints (e.g., steep slopes, wetlands, protected species habitat) overlap to exclude them from harvest?
Answer: Suitability or exclusion modeling using weighted overlay
Suitability or exclusion modeling uses weighted overlay to combine multiple constraint layers and identify areas that meet all exclusion criteria.
A forester exports GIS stand data to a KML file. What is the most likely intended use?
Answer: Viewing the data in Google Earth or another KML-compatible viewer
KML (Keyhole Markup Language) is designed for display in geographic browsers like Google Earth, making it useful for sharing spatial data with non-GIS users.
Which USGS product provides standardized 1/3 arc-second (approximately 10 m) elevation data widely used for terrain analysis in US forest GIS applications?
Answer: 3D Elevation Program (3DEP)
The USGS 3D Elevation Program (3DEP) provides high-quality, standardized elevation data including 1/3 arc-second DEMs across the conterminous US.
In GIS-based forest fragmentation analysis, which metric specifically measures the degree to which forest patches are connected to one another?
Answer: Connectivity or cohesion index
Connectivity or cohesion indices measure the physical connectedness of patches, which is critical for assessing habitat corridors and wildlife movement.
What is the primary purpose of using Web Map Services (WMS) in a forest GIS workflow?
Answer: To access and display map layers hosted on a remote server without downloading the full dataset
WMS allows GIS applications to request and display rendered map images from a remote server, enabling access to authoritative datasets without local storage.
A silviculturist wants to quantify how forest canopy closure has changed between two time periods using Landsat imagery. Which approach is most appropriate?
Answer: Multi-date image differencing or change detection analysis
Multi-date image differencing or change detection compares spectral values or classified maps between two dates to identify areas of canopy change.
Which GPS error source is largely eliminated by modern civilian GPS receivers through the use of dual-frequency signals or WAAS correction?
Answer: Satellite clock errors and ionospheric delay
Dual-frequency receivers and WAAS (Wide Area Augmentation System) corrections effectively remove satellite clock errors and ionospheric delay, the dominant GPS error sources.