GIS Cartography and Visualization 4 — Questions and Answers
Question 1: In GIS, what is a 'hillshade' raster used for?
- Classifying land use categories
- Simulating the shadow effect of sunlight on terrain for visual relief (Correct answer)
- Calculating slope gradient
- Identifying watershed boundaries
Correct answer: Simulating the shadow effect of sunlight on terrain for visual relief
A hillshade raster simulates the illumination of a surface by a hypothetical light source, enhancing the three-dimensional appearance of terrain.
Question 2: What is the primary purpose of map generalization?
- To increase map accuracy
- To simplify features appropriately for a given scale and purpose (Correct answer)
- To add more detail at smaller scales
- To convert raster data to vector
Correct answer: To simplify features appropriately for a given scale and purpose
Map generalization simplifies the complexity of geographic features so the map remains legible and useful at a specific scale.
Question 3: Which color scheme is recommended for a sequential thematic map showing values from low to high?
- Qualitative multi-hue scheme
- Single-hue light-to-dark gradient (Correct answer)
- Diverging scheme centered on zero
- Random hue assignment
Correct answer: Single-hue light-to-dark gradient
A single-hue sequential scheme (e.g., light yellow to dark green) intuitively communicates ordered magnitude from low to high values.
Question 4: What does a 'neatline' represent on a map layout?
- The grid of latitude/longitude lines
- The border or frame that encloses the map area (Correct answer)
- The line connecting two cities
- A contour line at regular intervals
Correct answer: The border or frame that encloses the map area
A neatline is the border that frames the map, separating the map image from surrounding marginalia such as the legend and title.
Question 5: Which technique places labels along roads and rivers so that the text follows the feature's curve?
- Point label placement
- Curved label placement (Correct answer)
- Offset label placement
- Callout label placement
Correct answer: Curved label placement
Curved (or splined) label placement orients text along the path of linear features like rivers and roads to improve readability.
Question 6: In remote sensing, what does 'spatial resolution' refer to?
- The number of spectral bands captured
- The smallest object size distinguishable in an image (Correct answer)
- The time between image acquisitions
- The radiometric depth of pixel values
Correct answer: The smallest object size distinguishable in an image
Spatial resolution is the ground area represented by each pixel; a 1-meter resolution image can detect features at least 1 meter in size.
Question 7: What GIS operation produces Thiessen (Voronoi) polygons?
- Buffering around polygon edges
- Dividing space so each polygon contains all locations closest to one input point (Correct answer)
- Intersecting two polygon layers
- Merging adjacent polygons by attribute
Correct answer: Dividing space so each polygon contains all locations closest to one input point
Voronoi tessellation partitions space into regions where every location is assigned to the nearest input point, creating proximity polygons.
GIS Cartography and Visualization 4
In GIS, what is a 'hillshade' raster used for?