M O N I T O R I N G URBAN F O R E S T CANOPY COVER USING SATELLITE IMAGERY A. PAUL NEWMAN Department of Geography, Portland State Universi~., Portland, OR 97207-0751, U.S.A.
(Received: 18 May 1992)
The urban forest is being recognized for not only aesthetic benefits but for carbon storage, air filtration, noise reduction and wildlife habitat. This acknowledgment has resulted in actions supporting the urban forest ranging from federal funding of state urban forestry programs to grassroot urban tree planting/advocacy groups. As with any forestry related project, there is an interest to know how much, and where the vegetation exists. Landsat satellite imagery (Thematic Mapper) has been proved effective for mapping the density (crown closure) of non-urban forests. This project uses this same imagery to map the density of the urban forest within the City of Portland, Oregon. In a second phase, this map along with other mapped information will form a model of the city for the purpose of locating areas that could sustain more vegetation. (This work is currently in progress and to date has produced a preliminary map of urban forest density using the imagery.) Computer image processing of the satellite imagery provides the basis for a city-wide map of urban forest density. Color infrared aerial photos supplies the initial ground truth for vegetation density and to also distinguish among trees, shrubs and grass. Particular emphasis is put on residential lands containing yard and street trees as mapping of urban natural areas (patches of remaining forest and meadows) has already been accomplished by other mapping projects. The final map of vegetation density will be a digital map ready for use within a geographic information sysem (GIS). This will start the second phase of the project where a more representative model of the urban environment will be constructed by joining the vegetation map with other GIS maps of population streets, tax parcels and zoning. The forest density map by itself will certainly show areas that are below average density. However, by making spatial correlations between the forest density map and population density, street density, tax parcel density and zoning, it is hoped to improve the accuracy in showing areas that could support more vegetation. References Campbell, J.B.: 1987, Introduction to Remote Sensing, New York: The Guilford Press. Cook, E.A. and Iverson, L.R.: 1991, 'Inventory and Change Detection of Urban Land Cover in Illinois Using Landsat Thematic Mapper Data', Illinois Natural History Survey, Champaign, Ill. Dorney, J.R., Guntenspergen, G.R., Keough, J.R. and Stearns, F.: 1984, 'Composition and Structure of an Urban Woody Plant Community', Urban Ecology 8, 69-90. Environmental Monitoring and Assessment 26:175-176, 1993. (~) 1993 Kluwer Academic Publishers. Printed in the Netherlands.
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Harris, L.D.: 1984, The Fragmented Forest, University of Chicago Press. Hobbs, E.R.: 1988, 'Species Richness of Urban Forest Patches and Implications for Urban Landscape Diversity', Landscape Ecology 1, 141-152. Jackson, Kenneth J.: 1985, Crabgrass Frontier, Oxford University Press. Kaplan, R.: 1984, 'Impact of Urban Nature: A Theoretical Analysis', Urban Ecology 8, 189-197. Kuchler, A.W.: 1967, Vegetation Mapping, New York: Ronald Press Company. Laurie, I.C. (Ed.): 1979, Nature in Cities: The Natural Environment in the Design and Development of Urban Green Space, John Wiley & Sons. McBride, J.R. and Froehlich, D.: 1984, 'Structure and Condition of Older Stands in Parks and Open Space Areas of San Francisco, CA', Urban Ecology 8, 165-178. Poracsky, J.: 1990, 'Portland's Urban Natural Area Inventory', in: Proceedings of Country in the City IlL Portland State University. In Press. Pryde, ER.: 1988, 'An Inventory and Evaluation of Natural Areas in San Diego County', Yearbook of the Association of Pacific Coast Geographers, Vol. 50. Richards, N.A., Mallette, J.R., Simpson, R.J. and Macie, E.A.: 1984, 'Residential Greenspace and Vegetation in a Mature City: Syracuse, N.Y.', Urban Ecology 8, 99-125. Rowntree, R.A.: 1984, 'Forest Canopy Cover and Land Use in Four Eastern United States Cities', Urban Ecology 8, 55-67. Rowntree, R.A.: 1989, 'Urban Forestry, Carbon Dioxide and Global Climate Change', SAFNational Convention, September 24--27. Sanders, R.A.: 1984, 'Some Determinants of Urban Forest Structure', Urban Ecology 8, 13-17. Sanders, R.A.: 1983, 'Classification of American Metropolitan Areas by Ecoregion and Potential Natural Vegetation', Research Paper NE-516, USDA Forest Service. Spirn, A.W.: 1984, The Granite Garden, New York: Basic Books, Inc. Publisheres. Unwin, D.: 1981, Introductory Spatial Analysis, New York: Methuen. Wang, S.: 1988, 'An Analysis of Urban Tree Communities Using Landsat Thematic Mapper Data', Landscape and Urban Planning 15, 11-22. Warner, S.B.: 1962, Streetcar Suburbs, Harvard University Press.
(Received: 18 May 1992)
The urban forest is being recognized for not only aesthetic benefits but for carbon storage, air filtration, noise reduction and wildlife habitat. This acknowledgment has resulted in actions supporting the urban forest ranging from federal funding of state urban forestry programs to grassroot urban tree planting/advocacy groups. As with any forestry related project, there is an interest to know how much, and where the vegetation exists. Landsat satellite imagery (Thematic Mapper) has been proved effective for mapping the density (crown closure) of non-urban forests. This project uses this same imagery to map the density of the urban forest within the City of Portland, Oregon. In a second phase, this map along with other mapped information will form a model of the city for the purpose of locating areas that could sustain more vegetation. (This work is currently in progress and to date has produced a preliminary map of urban forest density using the imagery.) Computer image processing of the satellite imagery provides the basis for a city-wide map of urban forest density. Color infrared aerial photos supplies the initial ground truth for vegetation density and to also distinguish among trees, shrubs and grass. Particular emphasis is put on residential lands containing yard and street trees as mapping of urban natural areas (patches of remaining forest and meadows) has already been accomplished by other mapping projects. The final map of vegetation density will be a digital map ready for use within a geographic information sysem (GIS). This will start the second phase of the project where a more representative model of the urban environment will be constructed by joining the vegetation map with other GIS maps of population streets, tax parcels and zoning. The forest density map by itself will certainly show areas that are below average density. However, by making spatial correlations between the forest density map and population density, street density, tax parcel density and zoning, it is hoped to improve the accuracy in showing areas that could support more vegetation. References Campbell, J.B.: 1987, Introduction to Remote Sensing, New York: The Guilford Press. Cook, E.A. and Iverson, L.R.: 1991, 'Inventory and Change Detection of Urban Land Cover in Illinois Using Landsat Thematic Mapper Data', Illinois Natural History Survey, Champaign, Ill. Dorney, J.R., Guntenspergen, G.R., Keough, J.R. and Stearns, F.: 1984, 'Composition and Structure of an Urban Woody Plant Community', Urban Ecology 8, 69-90. Environmental Monitoring and Assessment 26:175-176, 1993. (~) 1993 Kluwer Academic Publishers. Printed in the Netherlands.
176
A. PAULNEWMAN
Harris, L.D.: 1984, The Fragmented Forest, University of Chicago Press. Hobbs, E.R.: 1988, 'Species Richness of Urban Forest Patches and Implications for Urban Landscape Diversity', Landscape Ecology 1, 141-152. Jackson, Kenneth J.: 1985, Crabgrass Frontier, Oxford University Press. Kaplan, R.: 1984, 'Impact of Urban Nature: A Theoretical Analysis', Urban Ecology 8, 189-197. Kuchler, A.W.: 1967, Vegetation Mapping, New York: Ronald Press Company. Laurie, I.C. (Ed.): 1979, Nature in Cities: The Natural Environment in the Design and Development of Urban Green Space, John Wiley & Sons. McBride, J.R. and Froehlich, D.: 1984, 'Structure and Condition of Older Stands in Parks and Open Space Areas of San Francisco, CA', Urban Ecology 8, 165-178. Poracsky, J.: 1990, 'Portland's Urban Natural Area Inventory', in: Proceedings of Country in the City IlL Portland State University. In Press. Pryde, ER.: 1988, 'An Inventory and Evaluation of Natural Areas in San Diego County', Yearbook of the Association of Pacific Coast Geographers, Vol. 50. Richards, N.A., Mallette, J.R., Simpson, R.J. and Macie, E.A.: 1984, 'Residential Greenspace and Vegetation in a Mature City: Syracuse, N.Y.', Urban Ecology 8, 99-125. Rowntree, R.A.: 1984, 'Forest Canopy Cover and Land Use in Four Eastern United States Cities', Urban Ecology 8, 55-67. Rowntree, R.A.: 1989, 'Urban Forestry, Carbon Dioxide and Global Climate Change', SAFNational Convention, September 24--27. Sanders, R.A.: 1984, 'Some Determinants of Urban Forest Structure', Urban Ecology 8, 13-17. Sanders, R.A.: 1983, 'Classification of American Metropolitan Areas by Ecoregion and Potential Natural Vegetation', Research Paper NE-516, USDA Forest Service. Spirn, A.W.: 1984, The Granite Garden, New York: Basic Books, Inc. Publisheres. Unwin, D.: 1981, Introductory Spatial Analysis, New York: Methuen. Wang, S.: 1988, 'An Analysis of Urban Tree Communities Using Landsat Thematic Mapper Data', Landscape and Urban Planning 15, 11-22. Warner, S.B.: 1962, Streetcar Suburbs, Harvard University Press.
