While we argue that these offset results should not be used as a standalone evaluation, the water footprint community should consider atmospheric moisture recycling in future standards and guidelines.Īn overview on all derived factors (evaporation recycling ratios and characterization factors) is presented through the tables below. By aggregating them, we can determine combined net impacts. The results show that the negative effects of evaporation in the originating basins are counteracted (and partly overcompensated) by the positive effects of reprecipitation in receiving basins. Drawing on recently developed impact assessment methods, we produced characterization models for assessing the impacts of blue and green water evaporation on blue water availability for all evaluation perspectives. By considering both basin internal evaporation recycling (BIER > 5% in 2% of the world’s basins) and basin external evaporation recycling (BEER > 50% in 37% of the world’s basins), we were able to use three types of water inventories (basin internal, basin external and transboundary inventories), which imply different evaluation perspectives in water footprinting. Based on a previously developed dataset on the fate of land evaporation, we aim to close this gap by using comprehensive information on evaporation recycling in water footprinting for the first time.
However, the resultant source-receptor relationships between different drainage basins have not yet been considered in water footprinting. Most global water consumption is accounted for by evaporation (E), which is connected via bridges of atmospheric moisture transport to other regions on Earth. 4521-4528, dx.doi.org/10.Water consumption along value chains of goods and services has increased globally and led to increased attention on water footprinting. Water Accounting and Vulnerability Evaluation (WAVE): Considering Atmospheric Evaporation Recycling and the Risk to Freshwater Depletion in Water Footprinting,Įnvironmental Science and Technology, 48 (8), pp. Finkbeiner (2018):Įnhancing the Water Accounting and Vulnerability Evaluation Model: WAVE+Įnvironmental Science and Technology, in press, The applicability of the WAVE+ method is proven in a case study on sugarcane and results are compared to those obtained by other impact assessment methods. In order to support applicability in water footprinting and life cycle assessment, BIER and WDI are combined to an integrated WAVE+ factor, which is provided on different temporal and spatial resolutions. Differences compared to annual averages are relevant in semi-arid and arid basins characterized by a high seasonal variation of water consumption and availability.
Compared to the predecessor version, BIER and WDI are provided on an increased spatial and temporal (monthly) resolution. Based on the hydrological model WaterGAP3, WDI is updated and methodologically refined to express a basin’s vulnerability to freshwater deprivation resulting from the relative scarcity and absolute shortage of water. Potential local impacts resulting from water consumption are quantified by means of the water deprivation index (WDI).
Recent data from the atmospheric moisture tracking model WAM2-layers is used to update the basin internal evaporation recycling (BIER) ratio, which denotes atmospheric moisture recycling within drainage basins.
Enhancing the water accounting and vulnerability evaluation model: WAVE+ĭue to the increasing relevance of analyzing water consumption along product life cycles, the water accounting and vulnerability evaluation model (WAVE) has been updated and methodologically enhanced.