HandsOn_Ex02A : Global and Local Measures of Spatial Autocorrelation

Author

Yogendra Shinde

1. Introduction.

When we look at any province, town or state, we may get many questions in our mind like -

  1. Is development evenly distributed in the given province ?
  2. If the answer is ‘No’ then next question arises - Is there any sign of ‘Spatial Clustering’ ?
  3. If the answer for above question (#2) is ‘Yes’ then our next question will be - Where are these clusters ?

In the world of geospatial analytics, fundamental concepts of Spatial Dependence and Spatial Autocorrelation help us answer questions raised above.

1.1 Tobler’s First law of Geography

“Everything is related to everything else,but near things are more related than distant things.”

1.2 What is Spatial Dependence ? How it is measured ?

  • Spatial dependence is the spatial relationship of variable values (for themes defined over space, such as rainfall) or locations (for themes defined as objects, such as cities).

  • Spatial dependence is measured as the existence of statistical dependence in a collection of random variables, each of which is associated with a different geographical location.