GIS Exam 3 Questions And Answers
Geoprocessing -
correct answer ✅G tools are commonly used tools that we
normally use to prepare data for further analysis.
Buffer -
correct answer ✅creates polygon buffers around point, line, or
polygon features using a specified distance. Used to select features
in other layers. Ask a spatial question of what features are within a
certain distance of other features. Proximity analysis. Ex: What
pipelines are within 100 ft of oil wells.
Clip -
correct answer ✅features (either points, lines, or polygons) in one
layer using the extent of a polygon in another layer. Important toll
to help simplify data. Helps extract only the features needed within
a study area to create a smaller, more manageable dataset. Used
this tool to clip the MergedContours layer using the StudyArea layer
in the Caprock Canyons Project
Dissolve -
correct answer ✅Used to aggregate (combine) features in a single
layer based on common attribute values. Works on polygons and
line features.
,GIS Exam 3 Questions And Answers
Intersect -
correct answer ✅Calculates a set of new polygons based on the
combination of two or more layers. The new output layer contains
all of the features present only in the overlap of the input layers.
The input features can be point, line, or polygon, but the output
will contain features with the lowest dimension (ex. intersect lines
and polygons will output lines)
Union -
correct answer ✅Calculates a set of new polygons based on the
combination of two or more layers. The new output layer contains
all of the polygons present in the overlap of the input layers, plus
the polygons that exist where there is no overlap. Answers the
most basic question in geography: What is on top of what? Ex.
What vegetation is on top of what type of soils? So you can get an
idea of vegetation productivity with different soil types.
Merge -
correct answer ✅Used to combine 2 or more layers that do not
overlap into one layer. Used to combine either 2 or more point
layers, 2 or more line layers, or 2 or more polygon layers. Note that
we used this tool to merge the 2 contour (hypsography) layers in
the Caprock project.
,GIS Exam 3 Questions And Answers
Select by Location -
correct answer ✅Selects feature in one layer based on a spatial
relationship to features in another layer. There can be several
different types of spatial relationships between layers. These
relationships include selecting features that are completely within,
or selecting features that intersect, as well as other types of spatial
relationship.
Spatial Analysis in GIS -
correct answer ✅The 2 volume ESRI Guide to GIS Analysis
describes 11 basic types of spatial analysis that can be
accomplished with a GIS. The following are ex. of each of these
Spatial Analysis capabilities. Can be used to do 11 different things.
Basic Measurement -
correct answer ✅Can use the basic Measure tool or the Point
Distance tool in the ArcToolbox. a.) distance: distance between
point features, distance between line features, distance between
polygon features, or any combination of the above. b.) length: dist.
along a line feature -Calculate the distance along a road, pipeline or
stream segments, perimeter of a polygon - calculate the length of
fenced needed to enclose a pasture c.) area: area of a polygon or
multiple polygons-calculate the total area of a lake, or land use
types in a city, county or state. NOTE: If you import a shape file to a
geodatabase, ArcGIS automatically calculates a length and area
, GIS Exam 3 Questions And Answers
field: for a line layer, the length-field value is the length of each line
feature, for a polygon layer, the area-field value is the area and the
length-field value is the perimeter, the values calculated in these
length and area fields are based upon the units of the projection, if
the layer is unprojected, the length and area values are decimal
degrees (which is meaningless), if the layer is projected, the length
values will be in meters or ft and area values in m squared or feet
squared.
Mapping where things are -
correct answer ✅- mapping individual features (unique events),
feature types, feature subsets, and feature categories
a) mapping individual features (or unique events)
- mapping a single point, line, or polygon
--location of a single crime (point)
--location of a bus route (line)
--single parcel of land selected for development (polygon)
b) mapping individual feature types
- mapping all points, lines, or polygons in a layer
--location of all crimes (points)
--location of all roads (lines)
--location of all land parcels (polygons)
Geoprocessing -
correct answer ✅G tools are commonly used tools that we
normally use to prepare data for further analysis.
Buffer -
correct answer ✅creates polygon buffers around point, line, or
polygon features using a specified distance. Used to select features
in other layers. Ask a spatial question of what features are within a
certain distance of other features. Proximity analysis. Ex: What
pipelines are within 100 ft of oil wells.
Clip -
correct answer ✅features (either points, lines, or polygons) in one
layer using the extent of a polygon in another layer. Important toll
to help simplify data. Helps extract only the features needed within
a study area to create a smaller, more manageable dataset. Used
this tool to clip the MergedContours layer using the StudyArea layer
in the Caprock Canyons Project
Dissolve -
correct answer ✅Used to aggregate (combine) features in a single
layer based on common attribute values. Works on polygons and
line features.
,GIS Exam 3 Questions And Answers
Intersect -
correct answer ✅Calculates a set of new polygons based on the
combination of two or more layers. The new output layer contains
all of the features present only in the overlap of the input layers.
The input features can be point, line, or polygon, but the output
will contain features with the lowest dimension (ex. intersect lines
and polygons will output lines)
Union -
correct answer ✅Calculates a set of new polygons based on the
combination of two or more layers. The new output layer contains
all of the polygons present in the overlap of the input layers, plus
the polygons that exist where there is no overlap. Answers the
most basic question in geography: What is on top of what? Ex.
What vegetation is on top of what type of soils? So you can get an
idea of vegetation productivity with different soil types.
Merge -
correct answer ✅Used to combine 2 or more layers that do not
overlap into one layer. Used to combine either 2 or more point
layers, 2 or more line layers, or 2 or more polygon layers. Note that
we used this tool to merge the 2 contour (hypsography) layers in
the Caprock project.
,GIS Exam 3 Questions And Answers
Select by Location -
correct answer ✅Selects feature in one layer based on a spatial
relationship to features in another layer. There can be several
different types of spatial relationships between layers. These
relationships include selecting features that are completely within,
or selecting features that intersect, as well as other types of spatial
relationship.
Spatial Analysis in GIS -
correct answer ✅The 2 volume ESRI Guide to GIS Analysis
describes 11 basic types of spatial analysis that can be
accomplished with a GIS. The following are ex. of each of these
Spatial Analysis capabilities. Can be used to do 11 different things.
Basic Measurement -
correct answer ✅Can use the basic Measure tool or the Point
Distance tool in the ArcToolbox. a.) distance: distance between
point features, distance between line features, distance between
polygon features, or any combination of the above. b.) length: dist.
along a line feature -Calculate the distance along a road, pipeline or
stream segments, perimeter of a polygon - calculate the length of
fenced needed to enclose a pasture c.) area: area of a polygon or
multiple polygons-calculate the total area of a lake, or land use
types in a city, county or state. NOTE: If you import a shape file to a
geodatabase, ArcGIS automatically calculates a length and area
, GIS Exam 3 Questions And Answers
field: for a line layer, the length-field value is the length of each line
feature, for a polygon layer, the area-field value is the area and the
length-field value is the perimeter, the values calculated in these
length and area fields are based upon the units of the projection, if
the layer is unprojected, the length and area values are decimal
degrees (which is meaningless), if the layer is projected, the length
values will be in meters or ft and area values in m squared or feet
squared.
Mapping where things are -
correct answer ✅- mapping individual features (unique events),
feature types, feature subsets, and feature categories
a) mapping individual features (or unique events)
- mapping a single point, line, or polygon
--location of a single crime (point)
--location of a bus route (line)
--single parcel of land selected for development (polygon)
b) mapping individual feature types
- mapping all points, lines, or polygons in a layer
--location of all crimes (points)
--location of all roads (lines)
--location of all land parcels (polygons)
