Tree Canopy, NLCD 2001

Tree Canopy estimates for the Baltimore MSA from the 2001 NLCD. For NLCD 2001, a strategy for estimating tree canopy density at a spatial resolution of 30 m was developed (Huang et al., 2001). This strategy is similar to the method used to derive imperviousness, and is based on empirical relationships between tree canopy density and Landsat data, established using regression tree techniques. Several one-meter digital orthophoto quadrangles for each Landsat path/row are required to derive reference tree canopy density data needed for calibrating the relationships between canopy density and Landsat spectral data. As with the imperviousness data layer, the regression tree algorithm Cubist is used to develop the models and output a per-pixel estimate of tree canopy for all pixels. To aid the utility of the canopy estimate as an independent data layer, a non-forest mask is created to mask obvious non-forest pixels from the prediction. This procedure quantifies spatial distribution of tree canopy as a continuous variable from 1 to100%, and will be available as an independent product of NLCD 2001. The National Land Cover Database 2001 tree canopy layer for mapping zone 60 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of federal agencies (www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (EPA), the U.S. Department of Agriculture (USDA) Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (FWS), the Bureau of Land Management (BLM) and the USDA Natural Resources Conservation Service (NRCS). One of the primary goals of the project is to generate a current, consistent, seamless, and accurate National Land cover Database (NLCD) circa 2001 for the United States at medium spatial resolution. For a detailed definition and discussion on MRLC and the NLCD 2001 products, refer to Homer et al. (2003) and http://www.mrlc.gov/mrlc2k.asp . The NLCD 2001 was created by partitioning the U.S. into mapping zones. A total of 66 mapping zones were delineated within the conterminous U.S. based on ecoregion and geographical characteristics, edgematching features and the size requirement of Landsat mosaics. Mapping zone 60 encompasses whole or portions of several states in the mid-Atlantic region, including the states of New Jersey, Delaware, Maryland, Pennsylvania, Virginia, and the District of Columbia. Questions about the NLCD mapping zone 60 can be directed to the NLCD 2001 land cover mapping team at the USGS EROS Data Center (EDC), Sioux Falls, SD [phone] or [e-mail]. This is part of a collection of 221 Baltimore Ecosystem Study metadata records that point to a geodatabase. The geodatabase is available online and is considerably large. Upon request, and under certain arrangements, it can be shipped on media, such as a usb hard drive. The geodatabase is roughly 51.4 Gb in size, consisting of 4,914 files in 160 folders. Although this metadata record and the others like it are not rich with attributes, it is nonetheless made available because the data that it represents could be indeed useful. This is part of a collection of 221 Baltimore Ecosystem Study metadata records that point to a geodatabase. The geodatabase is available online and is considerably large. Upon request, and under certain arrangements, it can be shipped on media, such as a usb hard drive. The geodatabase is roughly 51.4 Gb in size, consisting of 4,914 files in 160 folders. Although this metadata record and the others like it are not rich with attributes, it is nonetheless made available because the data that it represents could be indeed useful.