(Untitled in English)

Research Project , Research Report 2007

Taikan Oki Institute of Industrial Science, The University of Tokyo
Toshiyuki Inuzuka Institute of Industrial Science, The University of Tokyo
Tomoko Nitta Institute of Industrial Science, The University of Tokyo
Naota Hanasaki National Institute for Environmental Studies
Shinjiro Kanae Institute of Industrial Science, The University of Tokyo

Abstract

Water footprints, or the total consumed water to produce commodities, were estimated for imported food to Japan, using an integrated global water resources model that consists of a physically based hydrological module and a crop growth module. In order to analyze the sustainability of water resources, the model was enhanced to quantify four major sources: precipitation, river, reservoirs, and non-renewable groundwater. The results showed that the water footprint of Japan was 42.7km3/yr. The virtual water, or the required amount of water that is needed to produce the imported food domestically, was estimated 62.7 km3/yr. Therefore, it indicates 20.0 km3/yr of water was saved through international trades. Among the total water footprint, 7.3 km3/yr (17%) was originated irrigation water, and 2.9 km3/yr (6.8%) was non-renewable groundwater.

Keywords:

Virtual water trade, global water resources assessment