Forests, Water, and People in the Northeastern Area
This project was designed to supplement and build upon the U.S. Forest Service "Forests on the Edge" study by focusing on the linkages between current watershed conditions, public and private forest land ownership patterns, surface water supplies, and human population (in 2000 and estimated for 2030). The initial analyses used the 1992 National Land Cover Data (NLCD); the analyses were replicated with the recently published 2001 NLCD. The project has also been done for the Southern region (region9) as well. Overviews are available for the Northeastern (20-state) Region and the Southern (13-state) Region. The top scoring watersheds for Step 3 and Step 4 are also available in both regions.
A four-step GIS overlay process was designed to identify and rank watersheds where forest conservation and stewardship is and will be especially important to protect drinking water supplies. The first step used a set of biophysical attributes (e.g., %forest, %agricultural land, road density, etc.) to develop an index of each large watershed's ability to produce clean water (APCW). The second step added the number of water consumers per unit area for each watershed to the APCW layer. The top scores represent watersheds with a high inherent ability to produce clean water upon which a large number of water consumers depend (e.g., the Chicopee River watershed in central Massachusetts that via the Quabbin Reservoir supplies water to 2.5 million people in Boston and 60 surrounding communities ...or the Upper Delaware River watershed that supplies ~50% of the water used by 9 million people in New York City.) The third step accounts for the proportion of private forest land (versus public or other forest land that is permanently protected from conversion to other uses) – combined with the preceding steps – to highlight the public water supply systems that depend upon the private forest land and landowners for source protection. The fourth and final step ("development pressure") uses US Census Bureau population projections for 2030 and David Theobold's algorithm that forecasts the spatial pattern of forest conversion to residential and associated commercial and industrial land use ...added to the output of the three preceding steps (APCW + Number of water consumers + proportion of private forest land + development pressure) to highlight the parts of the Northeastern Area where watershed forest conservation and management efforts are particularly important. Put another way, the top scoring watersheds (out of 540 in the Northeastern Area) are those that have a (1) very high ability to produce clean water, (2) large number of water consumers, (3) large proportion of private forest land (that is subject to conversion to other land uses), and (4) high forecasted (for 2030) population increases and subsequent loss of private forest land. The time for cost-effective forest conservation and water supply protection efforts is now ...to avoid costly pollution mitigation and water treatment upgrades to protect public health (and aquatic ecosystems) later.