AgResearch Ruakura Research Centre, Hamilton 3240, New Zealand.
AgResearch Ruakura Research Centre, Hamilton 3240, New Zealand.
Sci Total Environ. 2018 Oct 15;639:504-515. doi: 10.1016/j.scitotenv.2018.05.125. Epub 2018 May 26.
Water scarcity footprinting now has a consensual life cycle impact assessment indicator recommended by the UNEP/SETAC Life Cycle Initiative called AWaRe. It was used in this study to calculate the water scarcity footprint of New Zealand (NZ) milk produced in two contrasting regions; "non-irrigated moderate rainfall" (Waikato) and "irrigated low rainfall" (Canterbury). Two different spatial and temporal resolutions for the inventory flows and characterisation factors (CFs) were tested and compared: country and annual vs. regional and monthly resolution. An inventory of all the consumed water flows was carried out from cradle to farm-gate, i.e. from the production of dairy farm inputs to the milk and meat leaving the dairy farm, including all water uses on-farm such as irrigation water, cow drinking water and cleaning water. The results clearly showed the potential overestimation of a water scarcity footprint when using aggregated CFs. Impacts decreased by 74% (Waikato) and 33% (Canterbury) when regional and monthly CFs were used instead of country and annual CFs. The water scarcity footprint calculated at the regional and monthly resolution was 22 L/kg FPCM (Fat Protein Corrected Milk) for Waikato milk, and 1118 L/kg FPCM for Canterbury milk. The contribution of background processes dominated for milk from non-irrigated pasture, but was negligible for milk from irrigated pasture, where irrigation dominated the impacts. Results were also compared with the previously widely-used Pfister method (Pfister et al., 2009) and showed very similar ranking in terms of contribution analysis. An endpoint indicator was evaluated and showed damages to human health of 7.66 × 10 DALY/kg FPCM for Waikato and 2.05 × 10 DALY/kg FPCM for Canterbury, but the relevance of this indicator for food production needs reviewing. To conclude, this study highlighted the importance of using high-resolution CFs rather than aggregated CFs.
水资源稀缺足迹现在有一个由联合国环境规划署/SETAC 生命周期倡议推荐的共识生命周期影响评估指标，称为 AWaRe。本研究用它来计算新西兰（NZ）在两个截然不同地区生产的牛奶的水资源稀缺足迹：“无灌溉中度降雨”（怀卡托）和“灌溉低降雨”（坎特伯雷）。本研究测试并比较了两种不同的清单流和特征化因子（CFs）的时空分辨率：国家和年度与区域和月度分辨率。从摇篮到农场大门（即从奶牛场投入品的生产到牛奶和肉离开奶牛场）对所有消耗水的流量进行了清单编制，包括农场内所有用水，如灌溉水、奶牛饮用水和清洁水。结果清楚地表明，当使用聚合 CFs 时，水资源稀缺足迹可能会被高估。与使用国家和年度 CFs 相比，当使用区域和月度 CFs 时，影响分别降低了 74%（怀卡托）和 33%（坎特伯雷）。在区域和月度分辨率下计算的水资源稀缺足迹为怀卡托牛奶的 22 L/kg FPCM（脂肪蛋白校正奶），坎特伯雷牛奶的 1118 L/kg FPCM。对于无灌溉牧场的牛奶，背景过程的贡献占主导地位，但对于灌溉牧场的牛奶，灌溉的影响可以忽略不计。结果还与之前广泛使用的 Pfister 方法（Pfister 等人，2009）进行了比较，在贡献分析方面非常相似。评估了一个终点指标，结果表明怀卡托的 7.66×10 DALY/kg FPCM 和坎特伯雷的 2.05×10 DALY/kg FPCM 对人类健康造成损害，但该指标对食品生产的相关性需要重新评估。总之，本研究强调了使用高分辨率 CFs 而不是聚合 CFs 的重要性。
