Principles of GIS Final Exam Study
Material
Terrain Mapping - answer Can use both Raster and Vector data
Raster based data used for Terrain Analysis – answer DEM (digital elevation model)
Vector based data used for Terrain Analysis – answer TIN (Triangulated
irregular network)
True or False: DEMs are usually the primary data source for compiling
preliminary TINs through a conversion process. - answer True
True or False: Additional points - like GPS readings and LIDAR data - can be used in
TINs. - answer True
True or False: Line data like contour lines can be used to create TIN - answer True
Break lines - answer line features that represent changes of the land surface such as
streams, shorelines, ridges, and roads
Delaunay Triangulation - answer Used in TIN
• Here, all nodes (points) are
connected to the nearest
neighbors to form triangles,
• Triangles are equiangular, or
compact as possible
DEM represents... - answeran array of elevation points.
Errors in level 1 DEM - are classified into - answerGlobal error and Relative error
Global Errors - answerDue to displacement of DEM -
can be corrected by geometric transformation
Relative Errors - answerare local - significant errors
relative to neighboring elevations
Peaks and Sinks can be corrected by - answerFilling DEM data
, Contour Lines - answerlines
connecting points of
equal elevation
Contour Interval - answervertical distance
between contour lines
Base Contour - answercontour
from which contouring
starts
True or False: Contour lines can intersect? - answerFalse
Contour attribute tables contain... - answeran elevation attribute for
each contour polyline
Viewshed - answerthe portion of land visible from one or more viewpoints
Viewshed/Visibility Analysis - answerthe process of deriving viewsheds
Basis of analysis in viewshed is... - answerline of sight
operation or "sight line" (connects point and the target)
Applications of Viewshed - answerLookout Station Site Selection
Telephone Base Stations
Radio/TV
Slope identifies... - answerthe maximum rate of change
in value from each cell to its neighbors
Can be calculated as percent slope or degree of slope
Factors that influence Slope and Aspect measurement - answerResolution and Quality
of DEM, computing algorithm, local topography
Watershed - answeran area that drains surface water to a
common outlet
A watershed is a ______ unit - answerHydrological Unit
Watershed Delineation - answerprocess of using DEMs and Raster data to delineate
watersheds and derive features like stream networks
True or False: Watershed delineation takes place on various scales. - answerTrue
Material
Terrain Mapping - answer Can use both Raster and Vector data
Raster based data used for Terrain Analysis – answer DEM (digital elevation model)
Vector based data used for Terrain Analysis – answer TIN (Triangulated
irregular network)
True or False: DEMs are usually the primary data source for compiling
preliminary TINs through a conversion process. - answer True
True or False: Additional points - like GPS readings and LIDAR data - can be used in
TINs. - answer True
True or False: Line data like contour lines can be used to create TIN - answer True
Break lines - answer line features that represent changes of the land surface such as
streams, shorelines, ridges, and roads
Delaunay Triangulation - answer Used in TIN
• Here, all nodes (points) are
connected to the nearest
neighbors to form triangles,
• Triangles are equiangular, or
compact as possible
DEM represents... - answeran array of elevation points.
Errors in level 1 DEM - are classified into - answerGlobal error and Relative error
Global Errors - answerDue to displacement of DEM -
can be corrected by geometric transformation
Relative Errors - answerare local - significant errors
relative to neighboring elevations
Peaks and Sinks can be corrected by - answerFilling DEM data
, Contour Lines - answerlines
connecting points of
equal elevation
Contour Interval - answervertical distance
between contour lines
Base Contour - answercontour
from which contouring
starts
True or False: Contour lines can intersect? - answerFalse
Contour attribute tables contain... - answeran elevation attribute for
each contour polyline
Viewshed - answerthe portion of land visible from one or more viewpoints
Viewshed/Visibility Analysis - answerthe process of deriving viewsheds
Basis of analysis in viewshed is... - answerline of sight
operation or "sight line" (connects point and the target)
Applications of Viewshed - answerLookout Station Site Selection
Telephone Base Stations
Radio/TV
Slope identifies... - answerthe maximum rate of change
in value from each cell to its neighbors
Can be calculated as percent slope or degree of slope
Factors that influence Slope and Aspect measurement - answerResolution and Quality
of DEM, computing algorithm, local topography
Watershed - answeran area that drains surface water to a
common outlet
A watershed is a ______ unit - answerHydrological Unit
Watershed Delineation - answerprocess of using DEMs and Raster data to delineate
watersheds and derive features like stream networks
True or False: Watershed delineation takes place on various scales. - answerTrue
