Under contract to the California Department of Fish and Wildlife (CDFW) and the Bay-Delta Region for use in conjunction with the Delta Regional Ecosystem Restoration Implementation Plan, CDFW created a fine-scale vegetation map of portions of the Sacramento-San Joaquin River Delta. CDFW conducted field reconnaissance assistance for this project, as well as accuracy assessment (AA) field data collection; and Jeff Kennedy, Kristi Lazar, Jeanne Taylor and Jahalel L. Tuil [University of California Davis Information Center for the Environment (ICE)]; Brad Burkholder, Daniel Burmester, Curtis Hagen, Diana Hickson, Todd Keeler-Wolf, to assist in the AA field data collection. CDFW’s Vegetation Classification and Mapping Program (VegCAMP) provided in-kind service to allocate and score the AA.

The mapping study area, consists of approximately 725,600 acres, of which approximately 104,600 acres are natural vegetation, 555,100 acres agriculture and urban development, and 65,900 acres are open water or inundated lands. These acres were apart of Alameda, Contra Costa, Solano, Sacramento, San Joaquin, and Yolo counties. Work was performed on the project between 2005 and 2007. The primary purpose of the project was to further CDFW’s goal of developing fine-scale digital vegetation maps as part of the California Biodiversity Initiative Roadmap of 2018.

CNPS under separate contract and in collaboration with CDFW VegCAMP developed the floristic vegetation classification used for the project. The floristic classification follows protocols compliant with the Federal Geographic Data Committee (FGDC) and National Vegetation Classification Standards (NVCS).

The vegetation map was produced applying heads-up digitizing techniques using both the spring 2002 Stockton, Sacramento, and Delta High Resolution (1-foot) Orthoimagery and summer 2005 NAIP (1-meter) orthoimagery served as the base, in conjunction with ancillary data and imagery sources. Map polygons are assessed for Vegetation Type, Percent Cover, Exotics, Development Disturbance, and other attributes. The minimum mapping unit (MMU) is 2 acres for land use and vegetation; exceptions made for isolated land use, water, and critical vegetation types which were mapped to a 1-acre MMU.

Field reconnaissance and accuracy assessment enhanced map quality. There was a total of 131 mapping classes. The overall Fuzzy Accuracy Assessment rating for the final vegetation map, at the Alliance and Group levels, is 85% percent with 9 types falling below 70%.

More information can be found in the project report, which is bundled with the vegetation map published for BIOS here: https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=18211.