Geographic Information Systems Flashcards
7 cards from real CFP 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
Which watershed delineation method uses flow direction and flow accumulation rasters derived from a DEM to define catchment boundaries?
Answer: D8 or D-infinity flow routing algorithm
The D8 (deterministic 8-direction) or D-infinity algorithms route flow across DEM cells to compute accumulation and delineate watershed boundaries.
A fisheries analyst overlays impervious surface data with stream buffer zones to assess urban stormwater impacts. What does high impervious surface coverage within the buffer indicate?
Answer: Increased runoff, flashier flows, and potential water quality degradation
High impervious cover increases stormwater runoff volume and flashiness, elevating pollutant loads, peak flows, and thermal stress in receiving streams.
In GIS-based stock assessment support, what is the advantage of using acoustic Doppler current profiler (ADCP) data integrated into a GIS?
Answer: It provides spatially explicit water velocity and discharge for habitat modeling
ADCP data integrated into GIS provides spatially referenced current velocity and discharge measurements that can be linked to fish habitat models.
A biologist creates a 100-year floodplain map by combining a DEM with FEMA flood zone data. What is the primary fisheries application of this product?
Answer: Identifying off-channel floodplain habitat available during high-flow events
Floodplain maps identify areas inundated during floods, which are important off-channel habitats for fish feeding, spawning, and refugia during high flows.
Which GIS interpolation method is most appropriate when stream temperature monitoring stations are sparse but spatially correlated?
Answer: Kriging
Kriging uses the spatial autocorrelation structure of sampled data to produce optimal unbiased interpolated estimates across unsampled locations.
What is the purpose of a 'snapping' operation when digitizing stream networks in GIS?
Answer: Ensuring vertices and endpoints connect precisely to form a topologically correct network
Snapping forces digitized vertices to connect exactly to existing features, preventing gaps or overshoots that break network connectivity.
A GIS analyst uses Strahler stream ordering on a river network layer. A 4th-order stream is formed when:
Answer: Two streams of the same order join
In Strahler ordering, a stream of order n is created only when two streams of the same order n-1 converge, so two 3rd-order streams form a 4th-order stream.