Regional water coefficients for U.S. industrial sectors

- Water coefficients are fundamental measures of water uses by the economy.
- Water coefficients are required for effective water systems management and for water security.
- Water uses vary by industry and by local environmental and technological conditions.
- Regional water coefficients are more accurate and can be estimated using ecological regions.

Designing policies for water systems management requires the capability to assess the economic impacts of water availability and to effectively couple water withdrawals by human activities with natural hydrologic dynamics. At the core of any scientific approach to these issues there is the estimation of water withdrawals by industrial sectors in the form of water coefficients, which are measurements of the quantity of water withdrawn per dollar of GDP or output. In this work we focus on the contiguous United States and on the estimation of water coefficients for regional scale analyses. We first compare an established methodology for the estimation of national water coefficients with a parametric one we propose. Second, we introduce a method to estimate water coefficients at the level of ecological regions and we discuss how they reduce possible biases in regional analyses of water systems. We conclude discussing advantages and limits of regional water coefficients.