I am trying to estimate hydraulic head using SRTM DEM. My objective is to calculate hydropower potential using the hydraulic head and inflow among others.
How do I get an estimate of head?
I am using ArcGIS Desktop 10.
In GIS terminology what most closely approximates what you desire is known as "Darcy Velocity and Darcy Velocity". You will find them both in the Groundwater Toolset. This lecture PDF explains the relationship between the Darcy Calculation and Hydraulic Head. The summary from Columbia University explains the relationship between Darcy's Law and Hydraulic Head. the GIS software most often used is GMS and not ArcGIS as Hydraulic Head is most often associated with groundwater flow.