posted on 2013-11-05, 00:00authored byMontserrat Núñez, Stephan Pfister, Philippe Roux, Assumpció Antón
This
study aimed to provide a framework for assessing direct soil-water
consumption, also termed green water in the literature, in life cycle
assessment (LCA). This was an issue that LCA had not tackled before.
The approach, which is applied during the life cycle inventory phase
(LCI), consists of quantifying the net change in the evapo(transpi)ration
of the production system compared to the natural reference situation.
Potential natural vegetation (PNV) is used as the natural reference
situation. In order to apply the method, we estimated PNV evapotranspiration
adapted to local biogeographic conditions, on global dry lands, where
soil-water consumption impacts can be critical. Values are reported
at different spatial aggregation levels: 10-arcmin global grid, ecoregions
(501 units), biomes (14 units), countries (124 units), continents,
and a global average, to facilitate the assessment for different spatial
information detail levels available in the LCI. The method is intended
to be used in rain-fed agriculture and rainwater harvesting contexts,
which includes direct soil moisture uptake by plants and rainwater
harvested and then reused in production systems. The paper provides
the necessary LCI method and data for further development of impact
assessment models and characterization factors to evaluate the environmental
effects of the net change in evapo(transpi)ration.