Delta Smelt Summer-Fall Habitat Suitability Analysis
Delta Smelt Summer-Fall Habitat Suitability Analysis
Temperature and salinity stratification are observed in regions and times potentially affected by management actions. We examine stratification on two transects, one in the Deepwater Ship Channel and the Other in Montezuma Slough. We examine conditions in 2018, a below normal water year.
The animation below shows predicted historical hydrodynamic conditions during July 2018 since the DWSC is expected to occur in July. However, the DWSC flow action did not happen during these historical conditions. The typical dynamic is that density gradients strengthen during flood tide and stratification forms in the upper DWSC during ebb tide due to tidal straining and persists through slack water and early in flood tides. Temperature and salinity are typically well-mixed during and following peak flood tides. Salinity stratification is less pronounced in this region.
Sacramento Deep Water Ship Channel Transect, Historical Conditions, 2018 (Below Normal)
In 2018 an historical SMSCG action occurred starting on August 2. The animation shows propagation of the fresh water pulse from the landward (east) end of Montezuma Slough to the seaward (west) side of Montezuma Slough. Days after the action begins, salinity gradients strengthen at the seaward end of the slough resulting in tidally-variable stratification forming during ebb tides.