GIS Spatial Statistics 1 — Questions and Answers
Question 1: What does Moran's I measure in spatial analysis?
- Distance between geographic features
- Spatial autocorrelation of attribute values (Correct answer)
- Area coverage of polygon features
- Network connectivity between nodes
Correct answer: Spatial autocorrelation of attribute values
Moran's I measures spatial autocorrelation, indicating the degree to which nearby features have similar attribute values.
Question 2: A spatial weights matrix is used to:
- Calculate map scale between coordinate systems
- Convert between geographic projections
- Define neighborhood relationships between spatial features (Correct answer)
- Measure elevation differences across terrain
Correct answer: Define neighborhood relationships between spatial features
A spatial weights matrix formally defines which features are considered neighbors and quantifies the strength of their spatial relationships.
Question 3: Spatial autocorrelation, as described by Tobler's First Law, means that:
- All geographic features are equally related regardless of distance
- Nearby features tend to have more similar attribute values than distant features (Correct answer)
- GPS accuracy decreases with distance from the equator
- Map scale affects the accuracy of area measurements
Correct answer: Nearby features tend to have more similar attribute values than distant features
Tobler's First Law states that near things are more related than distant things, which is the foundation of spatial autocorrelation.
Question 4: Which statistic identifies statistically significant spatial clusters of high values (hot spots) and low values (cold spots)?
- Pearson's correlation coefficient
- Chi-square goodness-of-fit test
- Getis-Ord Gi* statistic (Correct answer)
- Standard deviation ellipse
Correct answer: Getis-Ord Gi* statistic
The Getis-Ord Gi* statistic produces z-scores and p-values to identify statistically significant hot spots and cold spots in spatial data.
Question 5: The mean center in spatial statistics is defined as:
- The median point of a feature's spatial distribution
- The average of all X and Y coordinates of features in a dataset (Correct answer)
- The center point of the minimum bounding rectangle
- The centroid of the largest polygon in a dataset
Correct answer: The average of all X and Y coordinates of features in a dataset
The mean center is calculated as the average of all X coordinates and the average of all Y coordinates, representing the geographic center of the dataset.
Question 6: A positive Moran's I value indicates that the spatial pattern is:
- Randomly distributed with no spatial pattern
- Dispersed with dissimilar values near each other
- Clustered with similar values near each other (Correct answer)
- Uniformly distributed across the study area
Correct answer: Clustered with similar values near each other
A positive Moran's I value indicates positive spatial autocorrelation, meaning similar values (either high or low) cluster together spatially.
Question 7: The standard deviational ellipse tool in GIS is used to:
- Perform kernel density estimation on point features
- Summarize the directional distribution and dispersion of features around the mean center (Correct answer)
- Identify spatial outliers in attribute data
- Calculate the convex hull of a point dataset
Correct answer: Summarize the directional distribution and dispersion of features around the mean center
The standard deviational ellipse captures the directional trend and spatial spread of features, showing their orientation and concentration around the mean center.
GIS Spatial Statistics 1
What does Moran's I measure in spatial analysis?