The River Corridor SFA at PNNL will transform understanding of spatial and temporal dynamics in river corridor hydrobiogeochemistry from reaction to watershed and basin scales, enabling mechanistic representation of river corridor processes and their responses to disturbances in multiscale models of integrated hydrobiogeochemical function. The river corridor science is conducted in the context of larger watershed processes that define boundary fluxes and exert other controls on hydrologic exchange. Therefore, our model framework must simulate land-surface and groundwater processes over domains much larger than the river corridor itself. A key element of our proposed work is understanding impacts of disturbances, with emphasis on wildfires and modified precipitation regimes, both prevalent disturbances that impact river corridor hydrobiogeochemistry. To enhance predictions, we will generate data, knowledge, and models that are transferable across diverse watersheds environments in the Columbia River Basin and other major U.S. river basins.
IDEAS-Watersheds Partnership with the River Corridor SFA at PNNL aims to achieve the SFA’s goal in translating the fundamental process understanding of river corridor hydrobiogeochemistry under baseline and disturbed conditions into predictive, interoperable models across watersheds, shown in the Figure. Managing the workflows for multiscale modeling of this type is a significant computational challenge, which includes multiscale integration of fundamental process understanding (genome to watershed scales) as well as integration with distributed data (data assimilation and uncertainty quantification) and coupling multiple modeling platforms (ATS, PFLOTRAN, CLM/ELM, SWAT, NEXSS). The IDEAS-Watersheds software ecosystem is leveraged to couple watershed hydrologic, biogeochemical and land-surface processes for integrated watershed modeling to route the water and other chemical constituents to river corridors. Community workflows for setting up watershed models are adopted to improve the scientific productivity, new workflow components are in turn contributed back to the community workflow to support the open science paradigm. In addition, the PNNL partnership will lead watershed and river corridor model intercomparison and benchmarking activities within the Yakima River Basin to better understand model structural difference, which will eventually lead to better transferable modeling approaches.
Image: Mechanistic understanding of river corridor hydrologic and biogeochemical process linkages is integrated into numerical models at scales from reactions to river basins.