||This proposal builds upon an existing model-based effort to develop a holistic view of the Bay-Delta-River-Watershed system. CASCaDE I developed a set of linked models to assess Delta ecosystem response to climate change. In CASCaDE II, we propose to refine and extend those modeling capabilities to
assess Delta ecosystem response to changes in climate and physical configuration. With a new state-of-the-art hydrodynamic and sediment model at its core, CASCaDE II will link models of climate, hydrology, hydrodynamics, sediment, geomorphology, phytoplankton, bivalves, contaminants, marsh accretion, and fish.
Our goals are to apply these linked models to 1) better understand Delta ecosystem function, 2) assess possible futures of the Delta under scenarios of climate and structural change, and 3) provide science-based information to support the DSC in its co-equal goals of water supply and ecosystem protection. The tools developed will provide an objective basis for anticipating and diagnosing Delta ecosystem responses to planned and unplanned changes. Experiments using the linked models are designed to address questions such as: How will climate change, together with new conveyance structures or increased flooded island habitat,
alter water flow and drinking water quality? With projected changes in residence time, turbidity, temperature,
and salinity, how will primary productivity, invasive bivalves, marsh processes, contaminant dynamics, and fish populations respond?