I'm a longtime lurker who finally decided to register on the forum (in no way driven by my need to have a certain question answered, of course...).
I was contacted by a colleague asking for help calcuating an input for a landslide model he's working on. Specifically, the model he's following (the Mora-Vahrson paper/model) asks for the slope input to be not in degrees or percents, but "relative slope." This is obtained by using the formula:
where the the min and max elevations are the lowest and highest points within a bounded area (most commonly 1 square km); these area searches/calculations are carried out across the desired study region without overlap.
I've tried multiple ways to calculate this using my existing skillset (limited; I'm an archaeologist with a background in GIS who was asked to help out...) and program (ArcGIS). I'm using a 90m resolution SRTM DEM for the area and have currently settled on using the Block Stats tool to calculate the MIN (and the MAX) for for a specified area 1000 x 1000m, and then entering those resultant rasters into the Raster Calculator as part of the Mora-Vahrson equation), and dividing by 1 (as the area of the Block Stat calculation, expressed in square km).
What I would like to gauge from more experienced GIS users is whether or not the Block Stats process I described seems to meet the requirements for the model's relative slope component. If anyone else has had experience calculating relative slope or a similar process, I'd be very interested to hear about it. Thanks.