@Martha Higgs

The study of Wang et al (2010) on "Variations of NDVI Over Elevational Zones During the Past Two Decades and Climatic Controls in the Qilian Mountains, Northwestern China (https://doi.org/10.1657/1938-4246-43.1.127)" might be of great help.

Dear Martha

For relationship analysis, it is very to have a large range of elevation. If you have this, in ArcGIS, you can design a point grid and extract ndvi and elevation and then calculate the correlation using any suitable software.

Regards,

Hormoz Sohrabi Thanks, do you know the exact method or could you point me in the right direction for designing a point grid to extract NDVI and elevation? What correlation should I use? I am familiar with R studio for statistical analysis

Nasir Hameed I have calculated zonal statistics as a table (min, max, range, mean, standard deviation, sum, variety, majority, minority and median) for my 2010-2020 MODIS NDVI change raster layer and my digital elevation model. Although I am finding difficult to determine over what elevation NDVI trends are positive - would you recommend using the mean value? Thanks!

@Martha Higgs

I think it is better to design some transects starting from the lowest elevation to the max. Then design points in regular spans (eg. 100 meters) on these transect. Then extract the ndvi and elevation in these points using:

https://desktop.arcgis.com/en/arcmap/10.3/tools/spatial-analyst-toolbox/extract-values-to-points.htm

It is better to first draw the point cloud (x: elevation, y: ndvi). Based on the point cloud, you can decide what analysis you should use.

Good luck,