Brady, Stephen J. and Flather, Curtis H. 1994. Changes in Wetlands on
Nonfederal Rural Land of the Conterminous United States from 1982 to 1987. Environmental
Management 18(5): 693-705.
ABSTRACT. Recent wetland area trends were estimated from the National
Resources Inventory (NRI) for nonfederal rural lands for the period 1982-1987. NRI-based
estimates of wetland area for states comprising the conterminous United States were highly
correlated with estimates made by the US Fish and Wildlife Service and with estimates of
coastal salt marsh wetlands made by the National Oceanic and Atmospheric Administration).
Net wetland area declined by 1.1% (approximately 363,200 ha) during the five-year study
period. Conversion to open water, primarily caused by flooding in western inland basins,
was responsible for altering extensive wetland areas (approximately 171,400 ha). Of the
human-induced wetland conversions, urban and built-up land was responsible for 48% if the
wetland loss, while agricultural development was indicated in 37% of the converted wetland
area. A decrease in rural land, and increases in both population, and urban and built-up
land were associated with wetland loss among states. Potential reasons for wetland loss
were different in 20 coastal states than in 28 inland states. Proportionately, wetland
loss due to development was three times greater in coastal states than inland states,
while agriculturally induced wetland losses were similar in both groups. The proportionate
declines of forested vs. nonforested wetlands were not significantly different among
states.