Description: Tree Canopy (TC) Assessment metrics for San Diego, CA. This dataset consists of TC metrics summarized using the California Communities Environmental Health Screening Tool (CalEnviroScreen 2.0) Results [October 2014 Update] (aka SENA_SanDiego) layer. The metrics presented in this table are based on 2014 high resolution land cover (landcover_2014_sandiego_13b.img). The TC Assessment is a top-down approach to analyzing the forest. Its purpose is to integrate high resolution land cover data with other GIS datasets to produce a set of detailed metrics on the forest that allow decision makers to know how much tree canopy currently exists (termed Existing TC) and amount of land where it is biophysically feasible to establish tree canopy on (termed Possible TC). Existing TC is determined by extracting all features classified as tree canopy from a high resolution land cover dataset. Possible TC is determined by identifying land where canopy could possibly exist. Possible TC in a GIS context is determined by overlaying high resolution land cover with cadastral and planimetric datasets to include building polygons and road polygons. Possible TC is queried out from this overlay and consists of all land that was not existing canopy, not water, not a building, and not a road. Possible TC is further divided into two subcategories: Possible-impervious and Possible-vegetation. Possible-impervious consists of all impervious land that, through modification, could support tree canopy. Examples of such features are parking lots, driveways (through overhanging coverage) and playgrounds. Possible-vegetation consists of all land that is low-lying vegetation, primarily grass or shrubs, which could conceivably be converted to support tree canopy. Examples of such features include residential lawns and playing fields. TC metrics do not serve to address the issues of where it is socially desirable or financially feasible to plant trees. Rather, the TC metrics serve as the basis for beginning to form answers to these questions. TC metrics are presented in the attribute table as both absolute area (in map units) and relative area (percentage of land area) per parcel. For example, an Existing TC Area (TC_E_A) value of 13,677 and an Existing TC Percentage (TC_E_P) of 21.8 indicate that for the parcel in question the area of Existing TC is 13,677 (in map units) and 21.8% of that feature is tree canopy. This table can be joined to the SENA_SanDiego feature class in this field using the TC_ID (a unique ID field created for this project) attribute field or the TC_ID attribute field (from the original feature class).
Service Item Id: ff967db787a945cb94c31ae9ad838754
Copyright Text: University of Vermont Spatial Analysis Laboratory in cooperation with the City of San Diego.