Ya you can estimate crop may ...
Published by P. B. Vekariya, Junagadh Agricultural University, Junagadh (Gujarat) - Assistant Professor
Ya you can estimate crop may be by GIS and remote sensing , crop water requirements, animal water requirements, human and industrial water requirements, for all estimation collect data from past to present as possible years, collect scientific information about daily consumption per unit. Area may be river basin or administrative area like district or state etc. calculate and determine the crisis will be or not along with rainfall availability water. ( in one project I have made water balance of part of India in this water was found excess then requirement, it helps you in your region water balance. water is excess or scare according new policy may form)