Spatial Autocorrelation and Areal Data

HES 505 Fall 2024: Session 20

Carolyn Koehn

Objectives

By the end of today you should be able to:

  • Use the spdep package to identify the neighbors of a given polygon based on proximity, distance, and minimum number

  • Understand the underlying mechanics of Moran’s I and calculate it for various neighbors

  • Distinguish between global and local measures of spatial autocorrelation

  • Visualize neighbors and clusters

Revisiting Spatial Autocorrelation

Spatial Autocorrelation

  • Attributes (features) are often non-randomly distributed

  • Especially true with aggregated data

  • Interest is in the relationship between proximity and the feature

  • Difference from kriging and semivariance