GIS Spatial Analysis Methods 4

Question 1

What is 'map algebra' as used in raster GIS analysis?

Accepted Answer

Mathematical operations applied to raster layers on a cell-by-cell basis

Answer

Map algebra performs mathematical and logical operations on raster grids at the individual cell level to create new output rasters.

Question 2

Which spatial analysis technique would you use to determine how many customers live within a 10-minute drive of each store location?

Accepted Answer

Network-based service area analysis

Answer

Network-based service area analysis follows road network topology to calculate travel-time zones around facilities, unlike simple Euclidean buffers.

Question 3

In spatial statistics, what does a high G-statistic (Getis-Ord Gi*) value indicate?

Accepted Answer

A hot spot — cluster of high values

Answer

A high positive Gi* statistic indicates that a location and its neighbors have significantly higher values than the global average, forming a hot spot.

Question 4

What is the 'modifiable areal unit problem' (MAUP) in spatial analysis?

Accepted Answer

Statistical results that change depending on how areal units are defined or aggregated

Answer

MAUP refers to how spatial analysis results can change significantly depending on the size and shape of the zones used for aggregation.

Question 5

Which spatial relationship operator would select all parcels that share a boundary with a flood zone polygon?

Accepted Answer

Touches

Answer

The 'Touches' spatial relationship selects features that share a boundary or endpoint but whose interiors do not overlap.

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Practice Test

GIS Spatial Analysis Methods 4