Sixty-three Years of Land Alteration in Erie Township

Land use and land cover (LULC) was mapped using historical aerial photos (1940) and contemporary QuickBird satellite imagery (2003) for a 100 km2 area covering portions of Erie Township, Michigan, and Toledo, Ohio on the western end of Lake Erie. This area serves as a microcosm of conditions elsewhere on the Great Lakes coast, containing a range of human-altered to natural landscapes. Geographic information system analysis was used to measure LULC change within the study area based on the 1940 and 2003 maps, and to illustrate the use of historical aerial photos and data to quantify changes in anthropogenic pressures to coastal ecosystems. Agriculture was and is the main land use in the study site, constituting 78% and 55% of upland area in 1940 and 2003, respectively. Most conversions to other land uses originated as agricultural lands. Transportation changes over the time period included the loss of two major railroad yards and the gain of an interstate highway. The area of commercial and industrial development increased 12-fold, from 20 ha in 1940 to 246 ha by 2003. Major industries built after 1940 included an electrical power plant and a sanitary landfill. Residential development approximately doubled from 353 ha in 1940 to 717 ha in 2003, consistent with an 80% increase in population. Coastal ecosystems within the study area included a coastal spit (Woodtick Peninsula) and a large, partially-diked wetland behind it (Erie Marsh), both of which changed extensively over the time period studied. This approach offers a means of incorporating long-term observations into the evaluation of environmental condition in coastal wetlands. INDEX WORDS: Diked wetlands, erosion, Lake Erie, land use change, QuickBird, wetland loss.