Analyzing canopy cover effects on urban temperatures, Baltimore City, MD

The objective of this study was to assess tree influences on temperature in urban environments and specify urban canopy distribution that increases benefits resulting from reduced summer temperatures. Current canopy cover for the Baltimore, MD was quantified and characterized using the 2001 National Land Cover database. This data was used to generate 4 canopy distribution scenarios; REG, DEV, DEV-HI and PPI-DIST, each with percent canopy cover increases of 1.5, 2.0 and 2.5 times the current canopy. Canopy scenarios were applied to temperature regression equations to map temperature reductions under each of the 12 scenarios. There was a linear relationship between canopy increase and temperature reduction. Doubling canopy cover resulted in average daily temperature reductions of approximately 0.35ºC (+/-0.02). Hourly temperature reductions were greatest and most dispersed at night when the atmosphere was stable and wind speed was low. Large areas of continuous increased canopy cover exhibited the largest temperature reductions.;Keywords: Canopy, forest cover, land cover, temperature, urban forestry, atmospheric stability.