GISP - Geographic Information Systems Professional Spatial Analytical Methods Questions and Answers

Question 1

An environmental agency needs to identify the most suitable locations for a new wildlife preserve. They have several raster layers representing different criteria: proximity to water, land cover type, slope, and distance from existing roads. Each criterion has a different level of importance for the final decision. Which spatial analysis technique is most appropriate for combining these raster layers to create a final suitability map?

Accepted Answer

Weighted Overlay

Answer

Weighted Overlay is a multi-criteria evaluation technique used to combine multiple raster datasets. It allows the analyst to reclassify values to a common scale and assign different weights to each input layer based on its importance, creating an integrated suitability model.

Question 2

A crime analyst is studying the spatial distribution of burglaries and wants to determine if the incidents, when considering their locations and attributes (e.g., value of stolen goods), are statistically clustered, dispersed, or randomly distributed across the entire city. Which statistical measure is specifically designed to evaluate this type of global spatial autocorrelation?

Accepted Answer

Moran's I

Answer

Moran's I is a global statistic that measures spatial autocorrelation. It produces a single value that indicates whether the overall pattern of feature values is clustered, dispersed, or random across the study area. Getis-Ord Gi* is a local statistic used to identify the location of specific hot spots and cold spots, not to describe the overall global pattern.

Question 3

A fire department needs to create a map showing all areas that can be reached by a fire engine from a specific station within a 5-minute drive time, accounting for road speeds and turn restrictions. Which type of network analysis is most effective for creating this 'response zone' polygon?

Accepted Answer

Service Area Analysis

Answer

Service Area Analysis is used to find a region that encompasses all accessible streets within a specified impedance (e.g., a 5-minute drive time). The output is typically a polygon representing the reachable area, which is exactly what is needed for a response zone.

Question 4

Which of the following spatial interpolation methods is considered an 'exact' interpolator, meaning the resulting surface passes directly through all the input sample points, and calculates unknown values based on a weighted average where the influence of a sample point diminishes with distance?

Accepted Answer

Inverse Distance Weighting (IDW)

Answer

Inverse Distance Weighting (IDW) is a deterministic and exact interpolator. It assumes that the influence of a sample point decreases with distance. Because a sample point has a distance of zero from itself, it receives all the weight in the calculation, ensuring the interpolated surface honors the known data points precisely.

Question 5

A GIS analyst has a polygon layer of soil types and another polygon layer of land use zoning. To support a detailed environmental assessment, they need to create a new layer where the output polygons represent every unique combination of soil and zoning, and the attribute table contains the fields from both input layers. Which vector overlay operation should be used?

Accepted Answer

Union

Answer

The Union operation computes the geometric intersection of two polygon layers, but preserves all features and attributes from both inputs. The output contains all polygons from both layers, split where they overlap, and the resulting polygons inherit attributes from both original layers.

GISP - Geographic Information Systems Professional Practice Test

GISP - Geographic Information Systems Professional Practice Test

GISP - Geographic Information Systems Professional Spatial Analytical Methods Questions and Answers