410
Box 15.3 Case Study: Physical Impacts of Climate Change on Water
Resources
This water systems modeling study (Miralles-Wilhelm et al. 2017) presents
an investigation of the impacts of climate change on water resources throughout the world, and specific effects on water-dependent sectors of the economy
such as urban, energy, and agriculture. The impacts are projected to vary
regionally (Fig. 15.4) and are likely to include changes in average hydroclimate patterns (precipitation, surface runoff, and streamflow), as well as
increases in the probability of extreme events.
Prudent management of water resources will be pivotal in addressing the
climate challenge—both for adapting to the effects of climate change as well
as for meeting global greenhouse gas mitigation goals. The precise consequences of climate change on the hydrological cycle are uncertain, which
makes adaptation especially challenging.
Uncertainty regarding impacts is partly a consequence of the limitations of
climate models; despite improvements in climate science, the Global Circulation
Models developed to project climate futures generate a wide range of projections that often disagree on both the direction and magnitude of precipitation
changes. Furthermore, these models do not have the precision required for planning and managing water resources. In addition to this, changes in the hydrological cycle imply that future water systems may not resemble the past
(non-stationarity), so historic trends as used in engineering designs, no longer
serve as a reliable guide for assessing and managing future risks.
nutrients, bacteria, pathogens and sediments across a wide range of watershed
scales and environmental conditions, and to assess the impacts of climate change,
land use, agricultural production, wetland drainage, and water management.
SWAT has been coupled with CWRF to capture crop–hydrology–climate interactions for distributed modeling over the continental USA, incorporating surface–
subsurface watershed processes, most pollutant sources, agricultural practices,
and human interventions.
Water systems models such as WEAP (Water Evaluation and Planning) focus
on the simulation of natural hydrological processes (e.g., evapotranspiration, runoff,
and infiltration) to enable assessment of the availability of water within a catchment,
integrating anthropogenic activities, such as water demands for energy generation
and food production, superimposed on the natural system to influence water
resources and their allocation (i.e., consumptive and non-consumptive water
demands) and enable evaluation of the impact of human water use. WEAP can be
used to simulate tailored scenarios specified by the model user.
Similar modeling approaches to water systems model development can be found in
the system dynamics literature. Such approaches combine physical processes based on
water balance principles, with water demands from diverse human activities. Examples
in this line of work are WaterSIM, spatial system dynamics modeling of water resources
systems, and the global water availability model. A useful synthesis review of system
dynamics modeling approaches is provided by Mirchi et al. (2012).
F. R. Miralles-Wilhelm
Box 15.3 Case Study: Physical Impacts of Climate Change on Water
Resources
This water systems modeling study (Miralles-Wilhelm et al. 2017) presents
an investigation of the impacts of climate change on water resources throughout the world, and specific effects on water-dependent sectors of the economy
such as urban, energy, and agriculture. The impacts are projected to vary
regionally (Fig. 15.4) and are likely to include changes in average hydroclimate patterns (precipitation, surface runoff, and streamflow), as well as
increases in the probability of extreme events.
Prudent management of water resources will be pivotal in addressing the
climate challenge—both for adapting to the effects of climate change as well
as for meeting global greenhouse gas mitigation goals. The precise consequences of climate change on the hydrological cycle are uncertain, which
makes adaptation especially challenging.
Uncertainty regarding impacts is partly a consequence of the limitations of
climate models; despite improvements in climate science, the Global Circulation
Models developed to project climate futures generate a wide range of projections that often disagree on both the direction and magnitude of precipitation
changes. Furthermore, these models do not have the precision required for planning and managing water resources. In addition to this, changes in the hydrological cycle imply that future water systems may not resemble the past
(non-stationarity), so historic trends as used in engineering designs, no longer
serve as a reliable guide for assessing and managing future risks.
nutrients, bacteria, pathogens and sediments across a wide range of watershed
scales and environmental conditions, and to assess the impacts of climate change,
land use, agricultural production, wetland drainage, and water management.
SWAT has been coupled with CWRF to capture crop–hydrology–climate interactions for distributed modeling over the continental USA, incorporating surface–
subsurface watershed processes, most pollutant sources, agricultural practices,
and human interventions.
Water systems models such as WEAP (Water Evaluation and Planning) focus
on the simulation of natural hydrological processes (e.g., evapotranspiration, runoff,
and infiltration) to enable assessment of the availability of water within a catchment,
integrating anthropogenic activities, such as water demands for energy generation
and food production, superimposed on the natural system to influence water
resources and their allocation (i.e., consumptive and non-consumptive water
demands) and enable evaluation of the impact of human water use. WEAP can be
used to simulate tailored scenarios specified by the model user.
Similar modeling approaches to water systems model development can be found in
the system dynamics literature. Such approaches combine physical processes based on
water balance principles, with water demands from diverse human activities. Examples
in this line of work are WaterSIM, spatial system dynamics modeling of water resources
systems, and the global water availability model. A useful synthesis review of system
dynamics modeling approaches is provided by Mirchi et al. (2012).
F. R. Miralles-Wilhelm