Hydrology experts at the U.S.
Department of Energy's (DOE's) Oak Ridge National Laboratory (ORNL) used
artificial intelligence and a physics-based understanding of streamflow to
create a model that provides highly accurate predictions of river temperatures,
even in waterways that lack sensors. The findings are published in the Journal of Hydrology.
The method is important to
hydropower utilities and dam operators for avoiding non-compliance risks,
mitigating damage to aquatic ecosystems, and understanding impacts to
downstream water users. The predictions have broad potential to support nuclear
and other power plant operations, strengthening the nation's energy and
economic security.
More than 70% of the nation's
electricity is generated by thermoelectric power plants that use water for
cooling, such as nuclear, natural gas, and coal-fired facilities. Information
about the availability and temperature of nearby water resources is crucial for
reliable and efficient power generation, in addition to agriculture, data
center siting, managing fish populations, and overall ecosystem health. Yet,
most U.S. waterways do not contain gauges or sensors that monitor temperature.
To construct a model to accurately
predict river temperatures, ORNL scientists used an AI/machine learning
approach called a long short-term memory network that's well suited to
analyzing patterns over time. The model learned how weather and landscape conditions
influence river temperatures over days, seasons and years.
"The model can improve our
understanding of both existing nuclear power plant operation and siting
suitability for the nation's nuclear expansion," said Sean Turner, senior
engineer in the Water Resources Science and Engineering Group at ORNL.
The model achieved an average
absolute error of only 1.1 degrees Celsius between predicted and actual values.
The error rate was comparable to conventional, data-intensive models that take
more time and resources to build and maintain. The framework:
- Consistently produced
seasonal warming and cooling patterns across diverse waterways.
- Maintained accuracy during
very hot weather events, times that are critical for grid reliability and
regulatory compliance for water withdrawal and release.
- Made better predictions as
scientists focused on nearby, relevant upstream areas that resulted in
cleaner signals for downstream temperature predictions, especially in
large rivers.
- Was trained using
inputs that are available for all 2.7 million river reaches across the
continental United States, meaning the model can generate daily in-stream
temperature estimates anywhere—even in completely ungauged watersheds.
"These deep-learning foundation models,
trained on vast amounts of data to recognize and predict long-term patterns,
are producing better and more transferable results than the models that people
have been building and tinkering with for the last 50 years," Turner said.
The team used
publicly available data sources including nine years of daily observations from
some 300 selected U.S. Geological Survey river gauges; ORNL-developed waterway
data reflecting precipitation, air temperature, solar radiation, humidity,
snowpack and other phenomena; ORNL-simulated daily streamflow statistics; and
federal data on watershed characteristics.
More
information on the model, River Temperature Time Series for Hydrothermal
Modeling and Analysis (RiTHyMs), is available on the DOE HydroSource platform maintained by
ORNL.
"We
wanted a system that could be applied anywhere in the nation, and that means we
needed to train it with data that's available for every waterway," Turner
said. "That's where ORNL and the datasets we've generated for HydroSource
came in."
Researchers
are now applying the model to the managed river systems and utility operations
of the Tennessee Valley Authority. They are also refining the model to enhance
predictions in mountainous regions, targeting western watersheds influenced by
glacial runoff, where other utilities have shown interest in water temperature
projections.
RiTHyMs leveraged ORNL's high-performance computing resources to rapidly train the continental-scale model on large datasets across hundreds of river basins. The resources are part of the Oak Ridge Leadership Computing Facility, a DOE Office of Science user facility at ORNL.
Source: This AI can read rivers almost anywhere in America, and utilities are paying close attention

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