In 1999, Circuit Rider Productions, Inc. mapped Giant Reed (Arundo donax) infestations along the mainstem of the Russian River through the support of a grant from the Sonoma County Water Agency. Infestations were mapped as polygonal boundaries derived from observations taken from low altitude flights during winter months when riparian vegetation had died back, allowing the surveyor to more easily document Giant Reed infestations. USGS DOQQ's as well as enlarged photographs that ranged in scale from 1:4,800 to 1:2,400 were used as the base map upon which the observations were delineated.
This dataset was then expanded upon during 2002 when Circuit Rider Productions, Inc. mapped additional Giant Reed infestations along the significant tributaries of the Russian River through a grant from California Department of Fish and Game. Infestations mapped during this project were delineated using the same data capture methods as the 1999 effort however, the base data for the 2002 effort utilized the 2000 Sonoma County Aerial Photos as the base map along with the USGS DOQQ's for the Mendocino County portion of the watershed. Due to the relatively small size of many tributary infestations, many infestations mapped during this effort were delineated as points, not polygons. However, during data maintence efforts in 2004, the original point data was buffered to a distance of five feet. Any original polygon delineations from the 2002 effort were unchanged.
Additionally, in 2002, Circuit Rider Productions began mapping infestations of Giant Reed that were removed by CRP's Restoration Implementation staff. The locational information for these infestations was captured using Trimble GeoExplorer and Geo3 GPS units. At times, data captured during these efforts was recorded as polygons however, in large the data was recorded as points. In 2004, data maintenance efforts converted the removed point locations to polygons through applying a 5 foot buffer.
Since 2004, the dataset has been updated periodically as CRP staff have undertaken additional removal projects. Individual infestations have been captured at removal project sites as polygons using a Trimble GeoExplorerXT GPS receiver and added to the dataset. These ground-truthed polygons replace the polygons from the earlier assessments at project sites. Some infestations have been digitized into the dataset from field map sketches by CRP staff as well. In addition, some infestations observed and filmed from low altitude flights in Winter 2006 have been digitized with reference to 2004 AirPhotoUSA color imagery and added to the dataset.
Funding for assessment and removal of Giant Reed in the Russian River Watershed by CRP has been provided by Sonoma County Water Agency, Community Foundation Sonoma County, and the following State of California agencies: Coastal Conservancy, Department of Fish and Game, Water Resources Control Board, Wildlife Conservation Board.