2

I'll explain my aim first: I am trying to create a single raster to represent vegetation resilience, I am doing this via change detection.

So far I have created 5 Change detection images, where 2000 is a reference image. I have done nothing to these except to display them with the classify tool with 1 st dev.

My problem is what is the best way to combine these images to demonstrate resilience. I'm assuming it's just a raster calculation.

6
  • Should mention I'm working on a method from: Washington-Allen, R. A., R. Ramsey, N. E. West and B. E. Norton (2008). "Quantification of the ecological resilience of drylands using digital remote sensing." Ecology and Society 13(1): 33. and it's the final equation I'm having trouble with not sure how to convert it for arcmap Sep 4, 2013 at 16:08
  • 2
    Please edit your question to either provide a link to the paper or reproduce the equation (with explanations of its symbols).
    – whuber
    Sep 4, 2013 at 20:14
  • Direct link to the pdf can be found here: tinyurl.com/mxnt7y6 the equation is number 7. where ij are row and coloumn of a given pixel A is your difference image and R your reference image. I've consider using linear regression on the 5 NDVI images instead as a measure of resilience, however I'm not sure how to approach that method as my dates are not consecutive. Sep 4, 2013 at 21:33
  • There's no problem doing regression on non-consecutive dates unless there is a large gap at one end or the other (for then the result depends too heavily on the lone isolated raster). One efficient way to do this is shown at gis.stackexchange.com/questions/52502. Although R code is given the procedure works pretty easily with Spatial Analyst: the formula for the slope will be a weighted (linear) combination of the five images and you can work out the weights based on the dates alone.
    – whuber
    Sep 4, 2013 at 21:36
  • Equation (7) in the paper makes no sense: it is a combination of scalars and an apparent vector. You will need to contact the authors and inquire concerning what they intended this stuff to say.
    – whuber
    Sep 4, 2013 at 21:42

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Browse other questions tagged or ask your own question.