CASCaDE: Computational Assessments of Scenarios of Change for the Delta Ecosystem

Created: 5/27/2011 - Updated: 2/27/2020


The CASCaDE project comprises an approach for determining how multiple drivers of environmental change would interact to change ecosystems targeted for restoration by CALFED. CASCaDE is aimed not at predicting the future, but at building an understanding of how the ecosystem might respond to a few plausible scenarios of change.

Design of this study is built from hypotheses that: (1) California's hydrology will change during the 21st century in response to global warming; (2) ecosystem structure and function will respond to changes in California's water supply, population, land use, sea level, constructed habitats and storage-conveyance facilities, and potential levee failures; (3) sufficient information is available to project plausible scenarios of change in each of these forcings; (2) climatic, hydrologic, hydrodynamic, water-quality, geomorphic and ecosystem processes are linked in the Bay-Delta-River-Watershed system, and thus models to project future conditions there must also be linked; and (5) strategic planning by CBDA will benefit from mechanistic, ecosystem-scale projections of future forcings and responses, posed as plausible scenarios of system change.

We are developing, modifying, and linking numerical models of key processes to explore likely BDRW responses to plausible future external and internal changes. The cascading effects of changes under these scenarios will be followed as they propagate from the climate system to watersheds to river networks to the Delta and San Francisco Bay. The resulting linked modeling system will provide a scenario evaluation capability that may be used subsequently (in follow-on projects) to assess a variety of possible management approaches to accommodating the projected changes.


Scientists, natural resource managers


The USGS is a science organization that provides impartial information on the health of our ecosystems and environment, the natural hazards that threaten us, the natural resources we rely on, the impacts of climate and land-use change, and the core science systems that help us provide timely, relevant, and useable information.


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