Development of updated AWARE characterization factors for water scarcity footprinting using and comparing different hydrological datasets

Abstract

The Available WAter REmaining (AWARE) method is a widely accepted tool for assessing the impact of water consumption on other water users in the context of Life Cycle Assessment (LCA). It is based on the evaluation of runoff data obtained via global hydrological models. In preparation for a future revision, this thesis collects suggestions for further development of the calculation of AWARE characterization factors (CFs). The emphasis is on (i) increased precision of area values, (ii) the exclusion of irrelevant watersheds, and (iii) the calculation of the Environmental Water Requirements (EWRs) from the discharge input data. While the watershed exclusion has no effect on the remaining watersheds, the other modifications result in varying degrees of change in the CFs depending on the sensitivity of the watershed under consideration. The second part of this paper examines CFs calculated from different climate data inputs to hydrologic modeling. Observation-based climate data leads to less similar CFs than simulation-based data. The uncertainty in the observation-based climate data probably must be attributed to the simulation-based data, too, due to the strong link to the bias correction. Therefore, the uncertainty regarding observational data presumably contributes significantly to the overall uncertainty of the simulation-based data, and the selection of the bias-correction dataset could be more influential to the AWARE CFs than the selection of individual climate simulations.