LCA-based Product Water Footprinting and a Case Study

In order to address the unsustainable use of global freshwater resources,indicators are needed which make the impacts of humans' activity on water resources transparent.In this study,a life cycle assessment(LCA)-based water footprinting method is introduced and demonstrated for a case study product of wheat produced in China.Comparing with existing virtual water-based water footprint calculation,the LCA-based method enables meaningful comparisons between products,production stages and production places in terms of their potential environmental impact.The case study shows that the average water footprint of wheat produced in Huanghe and Haihe drainage basins is 1262 L H2Oe·kg-1 while that of wheat produced in Changjiang drainage basin is only 31 L H2Oe·kg-1.It is indicated that wheat production exerts much more pressure on water resources in the water-scarce north than in the water-rich south.This LCA-based water footprinting method could provide scientific basis to guide strategic decisions for China's food production and sustainable water resources use.