the concept of a "water footprint" was coined in 2002, by arjen hoekstra, professor in water management at the university of twente, netherlands, and co-founder and scientific director of the water footprint network, whilst working at the unesco-ihe institute for water education, as a metric to measure the amount of water consumed and polluted to produce goods and services along their full supply chain. water footprint is one of a family of ecological footprint indicators, which also includes carbon footprint and land footprint. the water footprint concept is further related to the idea of virtual water trade introduced in the early 1990s by professor john allan (2008 stockholm water prize laureate). the most elaborate publications on how to estimate water footprints are a 2004 report on the "water footprint of nations" from unesco-ihe, the 2008 book "globalization of water", and the 2011 manual "the water footprint assessment manual: setting the global standard". cooperation between global leading institutions in the field has led to the establishment of the water footprint network in 2008.