arcGIS Quiz 2

The flashcards below were created by user kamrunsreno on FreezingBlue Flashcards.

  1. Clip
    Extracts input features that overlay the clip features.

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  2. intersect:
    Computes the geometric intersection of two coverages. Only those features in the area common to both coverages will be preserved in the output coverage.

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  3. Union
    Computes the geometric intersection of two polygon coverages. All polygons from both coverages will be split at their intersections and preserved in the output coverage.

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  4. Erase
    Creates a feature class by overlaying the Input Features with the polygons of the Erase Features. Only those portions of the Input Features falling outside the Erase Features outside boundaries are copied to the Output Feature Class.

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  5. Append
    Appends multiple input dataset into an already existing target dataset. Input datasets can be point, line or polygon feature classes, tables, rasters or raster catalogs.

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  6. Dissolve
    Aggregates features based on specified attributes

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  7. Spatial Join
    Creates a table join in which fields from one layer's attribute table are appended to another layer's attribute table based on the relative locations of the features in the two layers.
  8. Raster Calculator
    The Raster Calculator provides you a powerful tool for performing multiple tasks. You can perform mathematical calculations using operators and functions, set up selection queries, or type in Map Algebra syntax. Inputs can be raster datasets or raster layers, coverages, shapefiles, tables, constants, and numbers.
  9. Buffer
    Creates buffer polygons to a specified distance around the Input Features. An optional dissolve can be performed to remove overlapping buffers.
  10. Expand
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  11. Delineate a watershed
    • 1) Fill in the sinks
    • 2) Flow direction (from each cell)
    • 3) Flow Accumulation (# of cells flowing from each cell)
    • 4) Select out high flow accumulation values (Check to see that pour point on area of high flow accumulations)
    • 5) Watershed function to delineate Basin
  12. Spatial Interpolation 
    Thiessen polygon
    Converts input points to an output feature class of Thiessen proximal polygons.Thiessen polygons have the unique property that each polygon contains only one input point, and any location within a polygon is closer to its associated point than to the point of any other polygon.Image Upload 8
  13. Spatial Interpolation 
    Inverse Distance Weighted (IDW) is a method of interpolation that estimates cell values by averaging the values of sample data points in the neighborhood of each processing cell. The closer a point is to the center of the cell being estimated, the more influence, or weight, it has in the averaging process.

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  14. Slope
    The Slope tool calculates the maximum rate of change between each cell and its neighbors, for example, the steepest downhill descent for the cell
  15. Aspect
    Derives aspect from a raster surface. Aspect identifies the downslope direction of the maximum rate of change in value from each cell to its neighbors. Aspect can be thought of as the slope direction. The values of the output raster will be the compass direction of the aspect.
  16. Visibility
    Visibility analyzes visual exposure and performs viewshed analysis. The table below lists the types of questions that can be answered with the Visibility tool.
  17. Model
    • Data model—a statement about form or
    • about how the world looks (A raster layer)
    • ◦ Model as we are using here is an
    • expression of how the world is believed
    • to work; hence we are interested in the
    • expression of the process
  18. Forms of a Model
    • ◦ Visual Basic
    • ◦ Perl
    • ◦ Jscript
    • ◦ Python
  19. Model Uncertainty
    • Exists in the form of uncertainty in the input data
    • Exists over the uncertainty of parameters
    • ◦ Sensitivity analysis is important
    • Exists over the geographic extent on which it is run
    • Exists over the labeling of results
    • ◦ Labeling of 30% slope as hazardous
    • (logic)—how data described
Card Set:
arcGIS Quiz 2
2013-03-31 23:33:22

Quiz 2
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