Suisun Marsh Atlas: Notes on May Layers

Suisun Marsh Topographic Overview

A digital elevation model (DEM) provided by the CDFW Teale Data Center was used as a base for this map and many of the maps in the Atlas. The following information was provided in the file’s metadata regarding the source of the DEM:

The DEMs were extracted from the USGS National Elevation Dataset (NED), described by USGS as "a seamless mosaic of best-available elevation data. The 7.5-minute elevation data for the conterminous United States are the primary initial source data. In addition to the availability of complete 7.5-minute data, efficient processing methods were developed to filter production artifacts in the existing data, convert to the NAD83 datum, edge-match, and fill slivers of missing data at quadrangle seams. One of the effects of the NED processing steps is a much-improved base of elevation data for calculating slope and hydrologic derivatives."

Also included on this map is a study area boundary. This boundary is delineated by the ten foot contour line. Traditionally, the ten foot contour was used to define the Suisun Marsh for the Suisun Marsh Preservation Agreement and accompanying actions. The Suisun Marsh Implementation Plan will address issues in the greater watershed area.

Suisun Marsh Ownership

The ownership layer was derived from the Suisun Resource Conservation District's (SRCD) Ownership Location Map. The SRCD map was scanned and digitized in ArcView using USGS topographic maps for spatial reference.

Suisun Marsh Facilities

The "Facilities" map was taken from the link opens in new tab or windowInteragency Ecological Program and from the Department of Water Resources, Sacramento, GIS data layers.

Water Control Structures

The "Water Control Structures" map was created based on work by Mr. Paul Raquel. The water control structures layer includes drains, diversions, and gates.

Areas Flooded by Screened Diversions

The creation of this map was based on data supplied by the Suisun Resource Conservation District.

Tidal, Managed, and Muted Tidal Wetlands of Suisun (Marsh Types)

The "Marsh Types" map was taken from the 1999 San Francisco Estuary Institute's EcoAtlas CD, using "Level 3" categories. Tidal Marsh = "fully tidal" and "fully tidal bayland"; Muted Tidal Marsh = "muted tidal marsh"; Managed Marsh = "diked", "filled bayland", and "hillslope".

Suisun Tidal Wetland Restoration Projects

The "Suisun Tidal Wetland Restoration Projects" map was created and supplied by Wetlands and Water Resources.

Suisun Marsh Vegetation

The Suisun Marsh Vegetation map was created by the California Department of Fish and Game, Wildlife and Habitat Data Analysis Branch. This coverage represents the distribution of vegetation for Suisun Marsh based on interpretation of aerial photographs flown on June 16, 1999 and further updated with photographs flown July 5, 2000. Creation of this map included phases of delineation, digitization, vegetation data collection, vegetation classification, attribution, accuracy assessment, updates, and change detection.

Suisun Marsh Soils

The soils layer was taken directly from the United States Department of Agriculture Natural Resources Conservation Service Soil Survey Geographic link opens in new tab or window(SSURGO) Database.

Suisun Marsh circa 1800 and 1997 Maps

The past and present Suisun Marsh habitat map layers were taken directly from the San Francisco Estuary Institute's EcoAtlas version 1.50b4.

marsh at sunset