367
water and electricity are truly needed to enable health and security? To make these
words actionable, they must be translated into quantifiable metrics.
For example, according to the World Health Organization (WHO), every person
should have access to at least 50 L/day [L/person/day] of water that is safe, or clean
for washing, cooking, and drinking; affordable, costing less than 3% of household
income; and accessible, or less than 1 km and/or 30 min away (United Nations n.d.).
In contrast, in the Texas State Water Plan, the Texas Water Development Board
estimates that Texas municipal water demand for all purposes in 2010 was approximately 650 L/person/day.
We can convert these absolute–intensive metrics of per capita water use into a
relative–intensive metric to indicate that the average Texan has 13 times the WHO
standard for freshwater access. This metric could be used to discuss safe and healthy
levels of water consumption during drought. Furthermore, the maintaining proper
pressure in the municipal water supply for fighting fires is a critical safety issue and
is a reason for larger per capita water availability.
In turn, a certain amount of electricity per person is needed to be healthy and
safe. A minimum amount of electricity (less than 2% of the total in Texas of over
430 TWh/year) is required to run water and wastewater services, with additional
resources necessary for hospitals, police stations, traffic lights, and other city
services (Stillwell et al. 2010). Texas’ 2014 retail sales of electricity were 379 TWh
(10
12
Wh), comprised of 37% residential, 36% commercial, and 26% industrial
sales. These can be used as starting metrics to quantify desired power demand and
allocation during drought.
13.4 Conclusion
The central issue of the FEW nexus is the interaction of multiple dimensions: economic, social, and environmental. To be comprehensive, the more metrics, the better; however, to be comprehensible, fewer metrics are preferable.
A range of metrics using a range of units is needed to understand FEW interdependencies, and multiple considerations across a range of dimensions feed into our
framework for defining FEW metrics. Life cycle assessment (LCA) is one valuable
framework for calculating and defining metrics in order to characterize FEW systems. The inputs to LCA can come from both data and models.
In considering metrics by which we can improve decision-making, there are a
number of important considerations including scale and taxonomic class. The metric spatial and temporal scales at which activity takes place, ranges in space from
establishment-level to the meso/macro (or meso/macro) scale within a specific
region composed of many interacting facilities while ranging in time from concerns
of seconds to decades. The metric taxonomic class defines it across two dimensions
(intensive vs. extensive and absolute vs. relative) and how each dimensional combination can be used to reference how the metric relates to decision-making.
However, the metrics are most useful if we can both calculate them from observed
data and simulate them in models that give us insight into future impacts, options,
13 Metrics
water and electricity are truly needed to enable health and security? To make these
words actionable, they must be translated into quantifiable metrics.
For example, according to the World Health Organization (WHO), every person
should have access to at least 50 L/day [L/person/day] of water that is safe, or clean
for washing, cooking, and drinking; affordable, costing less than 3% of household
income; and accessible, or less than 1 km and/or 30 min away (United Nations n.d.).
In contrast, in the Texas State Water Plan, the Texas Water Development Board
estimates that Texas municipal water demand for all purposes in 2010 was approximately 650 L/person/day.
We can convert these absolute–intensive metrics of per capita water use into a
relative–intensive metric to indicate that the average Texan has 13 times the WHO
standard for freshwater access. This metric could be used to discuss safe and healthy
levels of water consumption during drought. Furthermore, the maintaining proper
pressure in the municipal water supply for fighting fires is a critical safety issue and
is a reason for larger per capita water availability.
In turn, a certain amount of electricity per person is needed to be healthy and
safe. A minimum amount of electricity (less than 2% of the total in Texas of over
430 TWh/year) is required to run water and wastewater services, with additional
resources necessary for hospitals, police stations, traffic lights, and other city
services (Stillwell et al. 2010). Texas’ 2014 retail sales of electricity were 379 TWh
(10
12
Wh), comprised of 37% residential, 36% commercial, and 26% industrial
sales. These can be used as starting metrics to quantify desired power demand and
allocation during drought.
13.4 Conclusion
The central issue of the FEW nexus is the interaction of multiple dimensions: economic, social, and environmental. To be comprehensive, the more metrics, the better; however, to be comprehensible, fewer metrics are preferable.
A range of metrics using a range of units is needed to understand FEW interdependencies, and multiple considerations across a range of dimensions feed into our
framework for defining FEW metrics. Life cycle assessment (LCA) is one valuable
framework for calculating and defining metrics in order to characterize FEW systems. The inputs to LCA can come from both data and models.
In considering metrics by which we can improve decision-making, there are a
number of important considerations including scale and taxonomic class. The metric spatial and temporal scales at which activity takes place, ranges in space from
establishment-level to the meso/macro (or meso/macro) scale within a specific
region composed of many interacting facilities while ranging in time from concerns
of seconds to decades. The metric taxonomic class defines it across two dimensions
(intensive vs. extensive and absolute vs. relative) and how each dimensional combination can be used to reference how the metric relates to decision-making.
However, the metrics are most useful if we can both calculate them from observed
data and simulate them in models that give us insight into future impacts, options,
13 Metrics