GIS Spatial Analysis Methods 5

Question 1

What is the primary difference between interpolation and extrapolation in the context of spatial analysis?

Accepted Answer

Interpolation estimates values within the range of sampled data while extrapolation estimates beyond it

Answer

Interpolation predicts values at unsampled locations within the convex hull of the data, while extrapolation extends predictions to areas outside the sampled extent.

Question 2

Which GIS operation would you use to calculate the total area of forest within each county polygon?

Accepted Answer

Tabulate intersection

Answer

Tabulate intersection calculates the area (or length/count) of one feature class that falls within each feature of another, making it ideal for area summaries by zone.

Question 3

In terrain analysis, what does a 'flow accumulation' raster represent?

Accepted Answer

The cumulative number of upstream cells draining into each cell

Answer

Flow accumulation counts the number of upslope cells that contribute flow to each cell, with high values indicating stream channels or drainage convergence zones.

Question 4

What is a 'spatial weights matrix' used for in spatial statistical analysis?

Accepted Answer

Defining which locations are considered neighbors and how much influence they have on each other

Answer

A spatial weights matrix formally encodes neighborhood relationships between spatial units, specifying which features are neighbors and the strength of those connections.

Question 5

Which spatial analysis method would be most appropriate for predicting housing prices across a city based on a sample of known sales?

Accepted Answer

Geographically weighted regression (GWR)

Answer

GWR fits local regression models at each location, allowing relationships between variables to vary across space, which is ideal for spatially non-stationary phenomena like housing prices.

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Practice Test

GIS Spatial Analysis Methods 5