Department of Civil and Environmental Engineering, Green Design Institute Carnegie Mellon University, Pittsburgh, PA, USA.
Environ Sci Technol. 2010 Mar 15;44(6):2126-30. doi: 10.1021/es903147k.
Effective water management is critical for social welfare and ecosystem health. Nevertheless, information necessary to meaningfully assess sustainable water use is incomplete. In particular, little information is available on supply chain or indirect water use for the production of goods and services in the United States. We estimate a vector of water withdrawals for all 428 sectors in the 2002 U.S. economic input-output table. The vector was applied using economic input-output life cycle assessment (EIO-LCA) methods to estimate direct and indirect water withdrawals for each sector's production, both in terms of total withdrawals and per dollar of output. Agriculture and power generation account for an overwhelming majority of direct water withdrawals (90%). A majority of water use (60%) is indirect ("embodied" or "virtual" water) with 96% of the sectors using more water indirectly in their supply chains than directly. The food and beverage industry accounts for 30% of indirect withdrawals. These results can be useful for environmental life cycle assessment of U.S. production and other studies, especially to avoid truncation errors due to boundary setting associated with process based life cycle impact assessments. However, we conclude that better information on water use would be helpful for effective water management.
有效的水资源管理对社会福利和生态系统健康至关重要。然而，对于有意义地评估可持续水资源利用所需的信息并不完整。特别是，关于美国生产商品和服务的供应链或间接用水的信息很少。我们估计了 2002 年美国经济投入产出表中所有 428 个部门的水资源抽取向量。该向量使用经济投入产出生命周期评估（EIO-LCA）方法进行了应用，以根据总抽取量和每单位产出，估算每个部门生产的直接和间接水资源抽取量。农业和发电占直接水资源抽取的绝大多数（90%）。大部分水的使用（60%）是间接的（“体现”或“虚拟”水），96%的部门在其供应链中使用的间接水比直接水多。食品和饮料行业占间接用水量的 30%。这些结果对于美国生产的环境生命周期评估和其他研究可能很有用，特别是可以避免由于与基于过程的生命周期影响评估相关的边界设置而导致的截断误差。然而，我们的结论是，更好的水资源利用信息将有助于有效的水资源管理。
