I'm using HydroSHEDS watersheds shapefiles for a proyect. Watershed are delinated applying the rules of Pfafstetter codification.
I need to merge/union the different polygons in a same shapefile. I need to select values for 2 different colums (values are the same, one is the HYBAS_ID and the other is the NEXT_DOWN) in the table of attributes, that way I can contruct the upstream basin. Also I need to keep some attributes and also sum others.
I'm using ArcGis 10.3.
Any idea in how can I do this?