August 06, 2018
Using Scale-Adaptive Modeling to Predict Watershed Function and Response to Disturbance
Approaches assimilate streaming data into models to estimate hillslope water partitioning over time.
While watersheds are recognized as Earth’s key functional unit for managing water resources, their hydrological interactions also mediate biogeochemical processes that support all terrestrial life and can lead to a cascade of downgradient effects. This work highlights the development of scale-adaptive modeling approaches to enable predictive understanding of how mountainous watersheds retain and release water, nutrients, carbon, and metals from episodic to decadal timescales.
A growing demand for clean water, food, and energy—in parallel with droughts, floods, early snowmelt, and other disturbances—are significantly reshaping interactions within watersheds throughout the world. This is particularly true for mountainous systems, such as the East River Watershed in Colorado, which is located in the Upper Colorado River Basin. This Basin supplies water to 1 in every 10 Americans and supports vast agriculture and hydropower operations along its reach. Because society is dependent on watersheds, new approaches that can accurately yet tractably predict watershed responses to disturbances are critical for resource management.
New approaches are being studied to quantify and predict how disturbances impact downstream water availability and biogeochemical cycling. The research is guided by a system-of-systems perspective and a scale-adaptive approach, where a predictive understanding of the response of archetypal watershed subsystems to disturbances is being developed as well as methods to aggregate such responses into predictions of cumulative watershed exports. Several recent advances include above- and-belowground characterization and monitoring approaches for understanding vegetation distribution; new modeling approaches for predicting bedrock-through-canopy hillslope interactions; and coupled modeling approaches that can assimilate streaming data into models to estimate hillslope water partitioning over time. Through the use of these tools, new watershed function insights can be gained, including how historical snowmelt and monsoon characteristics influence annual discharge across the entire watershed; controls on streamflow generation; and how future changes in vegetation and temperature may influence water partitioning at different positions in the watershed. Over 30 institutions are involved in advancing watershed hydrological-biogeochemical science at the East River, Colorado, watershed.
Lawrence Berkeley National Laboratory
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
This material is based on work supported as part of the Watershed Function Scientific (837) Focus Area funded by the Office of Biological and Environmental Research, within the U.S. Department of Energy Office of Science, under Award Number DE-AC02-05CH11231.
Hubbard, S. S., K. H. Williams, D. Agarwal, and J. Banfield, et al. "The East River, Colorado, Watershed: A mountainous community testbed for improving predictive understanding of multiscale hydrological-biogeochemical dynamics." Vadose Zone Journal. Special Section: Hydrological Observatories 17 (1), 1–25 (2018). https://dx.doi.org/10.2136/vzj2018.03.0061.