GIS Section 4.3

Question 1

What is reclassification in raster?

Answer 1

assigns pixels to new class with new values

Question 2

What is the output of a reclassify function in raster?

Answer 2

another raster

Question 3

What are some features you might look at for a suitability model of a new school?

Answer 3

• land use
• elevation
• recreation sites
• existing schools

Question 4

In vector data models, what sequence does the Reclassify function follow?

Answer 4

RDM
- Reclassify
- Dissolve
- Merge

Question 5

What are the conditions for a map overlay?

Answer 5

1. maps must share a spatial extent (be in the same place)
2. for raster: must have same resolution and pixel-to-pixel math operations must be possible

Question 6

What are vector overlay functions used for?

Answer 6

manipulating the spatial extent of maps

Question 7

What can resampling do?

Answer 7

manipulate the spatial extent of a map (fitting one map exactly to match the dimensions of another via transformation equations)

Question 8

What are three vector overlay functions?

Answer 8

• clip
• erase
  merge (append)

Question 9

What are the three types of resampling?

Answer 9

• Nearest neighbour
• Bilinear interpolation
• Cubic convolution

Question 10

What is the difference between the outputs of nearest neighbour vs bilinear interpolation resampling?

Answer 10

nearest neighbour output rasters have pixels with the same values as original, while bilinear interpolation resampling outputs different pixel values

Question 11

What are buffers?

Answer 11

• rings drawn around features at a specified distance