[Qgis-user] Spatio-temporal change/variation Indicator (Time Series)?

[celati Laurent]

Dear all,

Currently, i work with Qgis over an area in Europe, I am using a Landsat 5
time series from the 1980s to 2011. I am generating various indicators for
vegetation (NDVI), water content in vegetation (NDMI), and the presence of
open or even subsurface water. These indicators often have values between
-1 and 1 (like the NDVI). These indicators are generated for multiple
acquisition dates (at different months/seasons of the year). I was thinking
of prioritizing a "month-to-month" or season-to-season comparison for the
time being: January 1990 / January 2010 or Winter 1990 / Winter 2010, for
example. Once d those indices have been generated for each acquisition
date, what indicators/measurements would allow us to assess their
variation, evolution, and spatio-temporal change/dynamics? I imagine a
percentage would allow us to see the dynamics between two extreme dates, as
this post suggests:

https://gis.stackexchange.com/questions/415177/calculating-ndvi-percentage-change-in-qgis

But are there other indicators/measures of spatio-temporal variation and
change that could be used? Ideally, one that doesn't just focus on the two
"extreme" dates oriented of a time series (1990 and 2010) but also
resume/takes into account intermediate dates (1995, 1998, 2004, 2008, for
example)? So that the change indicator reflects the entire time series and
not just two extreme time steps?

Thanks so much
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