I would like to come up with the spatial variation of NDVI of a certain area. I have the average NDVI from 1998 to 2014. I'm using Arcgis 9.3
These 17 NDVI layers contains values range from -1 to 1. If you want to see the spatial variation i.e. where is the high/low vegetation then you need spatial analyst extension. Workflow for high vegetation is as below.
1.Load all 17 layers in the arc map and Cell Statistics Tool 2.Go to Toolbox>Spatial Analyst>Local>Cell Statistics 3.Set overlay statistic as MAXIMUM (as we need high vegetation so we need to extract higher values from NDVI layer) 4.Run the tool
I am attaching example for two layers as below
Same if you want low vegetation. Just set Minimum.
N.B.It does not give story by year/yearwise rather gives where was/is the high/low vegetation in the span of 17+ years There are many ways that depend on what you want. I used ArcGIS 10.1 but it is same in case of 9.3