Ecosystems Studies & Management
Resource Land Loss
Using the satellite-derived maps of impervious surfaces for 1990 and 2000, WHRC scientists estimated the loss of forest and agriculture to development that occurred during this decade. These estimates can provide an important baseline for the monitoring of the impacts of development across the Chesapeake Bay watershed. In turn, this can help states set goals for resource land protection and acquisition that are consistent with regional restoration goals. Between 1990 and 2000, a 61% increase in developed land (from 5,177 to 8,363 square kilometers) was observed. Most of this new development (64%) occurred on agricultural and grasslands while 33% occurred on forested land.
Some smaller municipalities lost as much as 17% of their forest lands and 36% of their agricultural lands to development, although in the outlying counties losses ranged from 0 - 1.4% for forests and 0 - 2.6% for agriculture (Figure 1). Fast growing urban areas surrounded by forested land experienced the most loss of forest to impervious surfaces. This can be observed in the northern Virginia area and around Richmond, VA in the southern part of the watershed. Agricultural land loss in Delaware, central Pennsylvania and central Maryland is associated with population growth and residential and commercial sprawl from Washington, DC and Philadelphia, PA.
Figure 1: The percent loss of forest and agricultural lands for each county in the watershed.
The maps below (Figure 2) show the contribution that each county in the watershed has made to forest and agricultural land loss. This provides a picture of hotspots of regional importance. Some of the counties surrounding Richmond, VA are responsible for 2.0 - 3.8% of the total forest loss in the watershed. Similar levels of deforestation can be observed in northern Virginia and central Maryland. The effects of development pressure from Washington, DC and Philadelphia, PA are even more apparent in the map of agriculture loss, where some counties in eastern Maryland, Delaware and southern Pennsylvania each account for 2.3 - 6.3% of the total regional loss.
Figure 2: The contribution of each county to the total loss of resource lands in the watershed.
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