An interesting read related ...
Published by Markus Pahlow, University of Canterbury - Senior Lecturer
An interesting read related to the subject (though a bit dated, when considering the speed at which concepts have developed and been applied in practice): Hoekstra, A.Y. (2007) 'Human appropriation of natural capital: Comparing ecological footprint and water footprint analysis', Value of Water Research Report Series No.23, UNESCO-IHE. available at: http://www.waterfootprint.org/Reports/Report23-Hoekstra-2007.pdf