U.S. Department of the Interior Chesapeake Bay Watershed Land Cover Data Series 1984, 1992, 2001, and 2006 U.S. Geological SurveyThe Chesapeake Bay Program U.S. Environmental Protection Agency
Montgomery County, Maryland Open water Low intensity urban Medium, High intensity urban Barren Tree canopy Shrub/ grass Agriculture/ open space Wetlands
York, Pennsylvania Open water Low intensity urban Medium, High intensity urban Barren Tree canopy Shrub/ grass Agriculture/ open space Wetlands
Land Change: 1984 – 1992 – Tree canopy decreased in every period, from 62.6% of the watershed land area in 1984 to 61.5% in 2006 (- 439,080 acres). Tree canopy decreased at the highest rate (-37,403 acres per year) between 2001 and Urban area increased 14% (355,146 acres) between 1984 and The annual rate of increase between 1984 and 1992 was twice the annual rate of increase of the latter two periods. The extent of agricultural and open space land decreased the most between 1984 and 1992 (- 8,700 acres per year). Agricultural and open space land decreased at much lower rates during the latter two periods (-2,110 and – 941 acres per year).