I am making a prospective map of fossil deposits using the "Weighted Overlay" ArcGIS tool. Input factor rasters are mostly topographic in nature (elevation, roughness, TPI, etc). Initially, I had planned on assigning the weightings of each factor based on expert opinion. However, due to the large number of input rasters it is now apparent that a less subjective, statistical technique of determining these weights would be preferable. I want to know if the analytical hierarchy process (AHP) can be suitably applied to determine the weights of the input rasters in this case.

If not: can you suggest any other methods to reduce the subjectivity of the designation of these weightings?

I am using ArcGIS 10.2



In my education in GIS, I met some statistical methods, however I never encountered better, than AHP for weighting objectively. Unfortunately, there was only one software which provided built-in AHP support (surprisingly an entire wizard) for this purpose: IDRISI. There are some user scripts for ArcGIS, like AHP 1.1 or AHP-OWA 2.0, which has Ordered weighted averaging. You should try these scripts and if they refuse to work, than you can always use a spreadsheet, a pen and a piece of paper or an online AHP calculator.

Just remember, you consistency ratio must be under 10% or 0.1. :)


This tool might be of benefit to you if you want to convert your rasters to vector. There is a OWA function and a WLC(weighted linear combination) there appears to be support for ArcGIS 10.1 and above.

http://mcda4arcmap.codeplex.com/ and a paper http://www.ryerson.ca/~crinner/pubs/Pages12-13_from_Cartouche86_Winter-Spring2013.pdf


Not entirely sure what you are after experimentally but you may want to investigate a Weights of Evidence approach.

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