GIS For Engineering (Knowledge) 2 — Questions and Answers
Question 1: In GIS engineering, what is a Digital Elevation Model (DEM) primarily used for?
- Storing land ownership records
- Representing terrain surface elevations (Correct answer)
- Tracking vehicle GPS positions
- Mapping underground utilities
Correct answer: Representing terrain surface elevations
A DEM stores elevation values for terrain surfaces and is used in engineering for slope analysis, drainage modeling, and site planning.
Question 2: Which coordinate reference system is most commonly used for large-scale engineering surveys in the United States?
- WGS 84
- NAD83 / State Plane (Correct answer)
- UTM Zone 1N
- EPSG:4326
Correct answer: NAD83 / State Plane
NAD83 State Plane Coordinate System is widely used in US engineering surveys because it minimizes distortion within individual states.
Question 3: What is the purpose of a topology check in an engineering GIS dataset?
- To convert raster data to vector
- To ensure spatial relationships between features are logically consistent (Correct answer)
- To reproject data to a new coordinate system
- To calculate attribute statistics
Correct answer: To ensure spatial relationships between features are logically consistent
Topology checks validate spatial relationships such as no gaps, no overlaps, and connectivity between features like road networks or utility lines.
Question 4: In GIS-based watershed delineation for civil engineering, which data input is most critical?
- Land use classification raster
- Digital Elevation Model (DEM) (Correct answer)
- Aerial photography
- Population density layer
Correct answer: Digital Elevation Model (DEM)
Watershed delineation relies on elevation data to determine flow direction and accumulation, making a high-quality DEM the essential input.
Question 5: What does 'spatial resolution' refer to in the context of raster GIS data used in engineering?
- The number of attribute fields in the dataset
- The smallest distinguishable area represented by one pixel (Correct answer)
- The coordinate accuracy of GPS measurements
- The file size of a raster image
Correct answer: The smallest distinguishable area represented by one pixel
Spatial resolution defines the ground area covered by each pixel; finer resolution means more detail but larger file sizes.
Question 6: Which GIS file format is an open standard commonly used to exchange vector geospatial data in engineering projects?
- DWG
- GeoJSON (Correct answer)
- MXD
- ECW
Correct answer: GeoJSON
GeoJSON is an open, text-based format for encoding geographic features and is widely supported across GIS platforms and web services.
Question 7: In pipeline engineering, a GIS network dataset is used to perform which type of analysis?
- Spectral classification
- Terrain slope calculation
- Connectivity and flow tracing (Correct answer)
- Land cover change detection
Correct answer: Connectivity and flow tracing
Network datasets model the connectivity of pipeline or utility networks, enabling flow tracing, isolation analysis, and routing.
GIS For Engineering (Knowledge) 2
In GIS engineering, what is a Digital Elevation Model (DEM) primarily used for?