When Models Talk: Integrated Human-Hydro-Terrestrial Modeling to Assess
Delaware River Basin Water Resource Vulnerability to Drought
Abstract
Holistic approaches are needed to investigate the capacity of current
water resource operations and infrastructure to sustain water supply and
critical ecosystem health under projected drought conditions. Drought
vulnerability is complex, dynamic, and challenging to assess, requiring
simultaneous consideration of changing water demand, use and management,
hydrologic system response, and water quality. We are bringing together
a community of scientists from the U.S. Geological Survey, National
Center for Atmospheric Research, Department of Energy, and Cornell
University to create an integrated human-hydro-terrestrial modeling
framework, linking pre-existing models, that can explore and synthesize
system response and vulnerability to drought in the Delaware River Basin
(DRB). The DRB provides drinking water to over 15 million people in New
York, New Jersey, Pennsylvania, and Delaware. Critical water management
decisions within the system are coordinated through the Delaware River
Basin Commission and must meet requirements set by prior litigation. New
York City has rights to divert water from the upper basin for water
supply but must manage reservoir releases to meet downstream flow and
temperature targets. The Office of the Delaware River Master administers
provisions of the Flexible Flow Management Program designed to manage
reservoir releases to meet water supply demands, habitat, and specified
downstream minimum flows to repel upstream movement of saltwater in the
estuary that threatens Philadelphia public water supply and other
infrastructure. The DRB weathered a major drought in the 1960s, but
water resource managers do not know if current operations and water
demands can be sustained during a future drought of comparable
magnitude. The integrated human-hydro-terrestrial modeling framework
will be used to identify water supply and ecosystem vulnerabilities to
drought and will characterize system function and evolution during and
after periods of drought stress. Models will be forced with consistent
input data sets representing scenarios of past, present, and future
conditions. The approaches used to unify and harmonize diverse data sets
and open-source models will provide a roadmap for the broader community
to replicate and extend to other water resource issues and regions.