Land Use
The way we live and use the land greatly influences the health of the Bay and its network of streams and rivers. Image courtesy Ben Longstaff/
IAN Image Library.
Land in the Chesapeake Bay watershed is used in many different ways, from high-density cities to sprawling suburbs to diverse types of agriculture. The way we live and use the land greatly influences the health of the Bay and its network of streams and rivers.
How is land used in the Chesapeake Bay watershed?
- About 58 percent of the Bay watershed is undeveloped and mostly forested.
- The remaining 42 percent of the watershed's land has been developed for other uses, such as:
The percentage of forested land is slipping as the rate of development increases. In the Bay watershed, approximately 100 acres of forest are lost each day, primarily to development of new roads and buildings to accommodate a growing population.
Where in the Chesapeake Bay watershed is land changing?
During the 1990s, the largest increases in development occurred near the major cities of Baltimore, Richmond and Washington, D.C. The specific counties that experienced the greatest amount of impervious surface change — used to measure the rate of development — include:
- Lancaster and York counties in Pennsylvania
- Fairfax and Henrico counties in Virginia
- Sussex County in Delaware
- Montgomery, Prince George's and Anne Arundel counties in Maryland
While some counties that lost farmland — such as Lancaster County, Pennsylvania, and Loudoun County, Virginia — experienced corresponding high rates of development, others — including Tioga County, Pennsylvania, and Albemarle County, Virginia — did not. These latter counties may be experiencing farmland abandonment for reasons other than development.
The highest percentages of forest loss are found in developing suburban counties across the Bay watershed. Changes are also taking place in rural counties that are dominated by forests, such as those in New York, northern Pennsylvania and south-central Virginia. These changes are likely associated with silviculture activities (managing forests to meet human needs) rather than development.
How has land in the Chesapeake Bay watershed changed over time?
Data produced in 2009 by MDA Federal for the U.S. Geological Survey (USGS) show how three types of land cover — farmland/open space, urban areas and tree canopy — in the Chesapeake Bay watershed changed between four time periods: 1984, 1992, 2001 and 2006. "Land cover" is measured by interpretation of satellite images that capture the sun's reflection off the earth's surface, while "land use" is the actual way an area of land is used (such as agriculture, forest or residential development).
- Farmland/open space decreased by 8,700 acres per year between 1984 and 1992, 2,110 acres per year between 1992 and 2001, and 941 acres per year between 2001 and 2006.
- The total amount of urban area in the Bay watershed increased by 14 percent, or 355,146 acres, between 1984 and 2006. The annual rate of increase between 1984 and 1992 was twice the annual rate of increase between 1992 and 2006.
- Tree canopy decreased from 62.6 percent of the watershed in 1984 to 61.5 percent in 2006, a loss of 439,080 acres. The highest rate of decline took place between 2001 and 2006, when the watershed lost 37,403 acres of tree canopy per year.
Download this PowerPoint for additional details about the land cover data. USGS is currently analyzing the data and will interpret and publish land cover trends in 2010.
- Causes and Consequences of Land Use Changes: Information from the U.S. Geological Survey on how land use changes affect the health of the Bay and its wildlife habitats.
- Land Use & Population Growth: Information from Maryland Sea Grant about urban sprawl and its effects on the Bay and watershed forests.
- Facts About Growth and Land Use: Fact sheet from the Chesapeake Bay Foundation on the effects of sprawl on both the environment and quality of life.
- Land Use: Reports and presentations from the Chesapeake Bay Funders Network with information on various land use topics.
- Sound Land Use: Links and information from the Chesapeake Bay Trust on using land wisely.
- Smart Growth: Program by the Maryland Department of Planning that supports growth around existing infrastructure to preserve natural areas.
- The State of Chesapeake Forests: A 2006 report by The Conservation Fund and the USDA Forest Service that details the importance of and threats to forests in the Bay watershed.