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Department of Epidemiology


Spatial Epidemiology


Topic:

Geostatistical Models and Methods

Presenter: Dr. Andrew Long

OVERVIEW and OBJECTIVES

In this module we investigate geostatistical methods. In particular, we are interested in the production of maps from data. The general procedure is as follows:

  • examine the data, to determine what kind of interpolation (mapping) is appropriate;
  • model the spatial autocorrelation of the data;
  • use the model to "krig" the data (generate the map); and
  • check the results.

OBJECTIVES: Those who successfully complete the module should

  • understand spatial autocorrelation as a function of space, with important characteristics such as the distance over which correlation exists, the relative size of the correlation, etc.;
  • understand the variogram and its relationship to kriging;
  • know how to model the variogram, and plausible models;
  • understand kriging interpolation and its relationship to the variogram;
  • be able to use geostatistical software to
    • create and model variograms, and know why it's done (decomposing sample variance to explore spatial autocorrelation),
    • krig, and know why it's done (make better assumptions about spatial autocorrelation to get better maps than arbitrary, ad hoc inverse-distance weighting and other methods provide).

OUTLINE

LAB

GUESTBOOK


SCENARIOS FOR DISCUSSION