I am working on a project where I have a polygon of a basin that I should create his base whose elevation begins at -1m and go down in every direction with a slope of 2%. Does anyone know how to do it automatically using ArcGIS?
You can compute the distance to your reference point (Euclidian distance tool), then you divide this distance by -50 and substrat 1 to the results in the raster calculator (map algebra tool).
Some explanations: the slope percentage is equal, by definition, to the maximum difference in elevation divided by the planimetric Euclidian distance. The Euclidian distance tool creates a surface with values of the planimetric distance. If you assume that the generated result (distance in the X/Y plane) is in fact an elevation value, then this would represent a DEM with a positive slope of 100%. Now if you divide the "synthetic" DEM values by -50, it becomes a DEM with a slope of -2% and an elevation of 0 at the location of your reference point. then you can remove 1 m from the all DEM, which will not modify the slope but set the elevation of the origin at -1 meter.