WRP Historical Habitats

Historical habitat distribution was referenced from the Historical Wetlands of the Southern California Coast: An Atlas of US Coast Survey T-Sheets, 1851-1889 report. Mapping was implemented by The Southern California Coastal Water Research Project (SCCWRP), the San Francisco Estuary Institute (SFEI) and the Center for Geographic Studies at California State University, Northridge (CSUN). The final methods report will describe the full list of sources used to develop the habitat maps for this other systems. Beaches, dunes, and upland habitat areas are not shown in this layer. The Science Advisory Panel agreed (Tenet #4) on having the quantifiable objectives based on the following habitat types: subtidal, unvegetated flats, and vegetated marsh, and therefore beaches and dunes are not shown in this layer.

This is a subset of the original Southern California T-sheets GIS Data set. Most of the original fields were removed from this version, but one field (Simp_Class) remains in this version. The label of the original Web_Class field (defined below) was changed to Original_C. A new field called "HabType_CW" was created to crosswalk the original habitat classifications in Original_C to reflect the terms used in the Southern California Restoration Strategy Update report. The crosswalk classifications in HabType_CW were as follows: "subtidal water" changed to "subtidal"; "Intertidal flat" changed to "unvegetated flat" and "vegetated wetland" changed to "vegetated marsh".

Description from original data source: Under the direction of some of the leading American scientists of the 19th century, the United States Coast Survey (USCS) created exceptionally accurate and detailed maps of the country's coastline. These surveys (commonly referred to as "T-sheets") are the single most important data source for understanding the physical and ecological characteristics of the US shoreline prior to substantial Euro-American modification. Their depictions of coastal wetlands and estuaries prior to major development are valuable tools for coastal zone planning and estuary management and form an important foundation for more detailed investigations of historical extent and condition of coastal wetlands.

Please visit http://www.caltsheets.org for more information, including links to the associated reports: Wetlands of the Southern California Coast: Historical Extent and Change over Time (Stein et al. 2014), and Historical Wetlands of the Southern California Coast: An Atlas of U.S. Coast Survey T-Sheets, 1851-1889 (T-Sheet Atlas) (Grossinger et al. 2011).

This dataset was created based on expert interpretation of georeferenced T-sheets spanning the entire coastline of Southern California. Mapping methodology is described in detail in Stein et al. 2014. This dataset (phase 2) updates and replaces earlier GIS datasets created for, and distributed concurrently with the 2011 T-sheet Atlas (phase 1).

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Attribute table fields:

Simp_Class: Simplified classification, used for summarizing historical habitat areas

Original_C (formerly labeled Web_Class): Simplified classification, used for symbology in web and paper cartography

HabType_CW: Habitat types crosswalked from Original_C to be consistent with the terminology used in the Southern California Restoration Strategy Update report. Habitat categories changed as follows: "subtidal water" changed to "subtidal"; "Intertidal flat" changed to "unvegetated flat" and "vegetated wetland" changed to "vegetated marsh".

SHAPE_Length = meters

SHAPE_Area = square meters