A Comparison of Rural and Urban Fluvial Systems as a Function of Land Cover Changes in Summit County, Ohio

Abstract

Population growth during the 20th century in Northeast Ohio has led to an overall increase in developed land cover and anthropogenic pollution such as fossil fuel combustion. Urban expansion and fossil fuel combustion result in an increase of polluted runoff into fluvial systems, which jeopardizes water quality, undermines infrastructure, and stresses local ecosystems that buffer floods. This study compares heavy metal pollution levels and land cover change during the 20th century in dammed impoundments within the rural Haskell Run watershed (Lake Butler), the rural Ritchie Run (Lake Litchfield), and the urban Mud Brook watershed (Old Mill Pond) in Northeast Ohio. Surficial sediment samples were collected from each impoundment to assess current pollution levels and sediment cores were collected for the past record of pollution. The two end-member watershed types have similar bedrock, glacial history, and climate, however, land cover differs greatly. Between 1985-2010, there was no land cover change in the rural Ritchie Run watershed, and in 2010, Ritchie Run had 3.4% developed land cover and 0.63% impervious cover. During the same period, the rural Haskell Run watershed increased by 1.37% in developed land cover, and in 2010, 12% of the Haskell Run watershed was developed land and 3.3% was impervious cover. Developed land cover, from 1985-2010, increased by 15.3% in the urban Mud Brook watershed, and in 2010, 74% was developed land cover and 23% was impervious cover. Old Mill Pond impoundment sediments were found to have higher heavy metal and ferrimagnetic concentrations, whereas, Lakes Butler and Litchfield sediments have comparatively lower heavy metal and ferrimagnetic concentrations. There is a moderate direct relationship iv between heavy metal and ferrimagnetic content. Therefore, magnetics can be used as an inexpensive and rapid screening tool for heavy metal pollution studies. The Old Mill Pond sediment core records an increase in heavy metal and ferrimagnetic concentration in the early 20th century, peaking in the 1940s-1960s when Cuyahoga Falls experienced a doubling in population. Since the 1970s-1980s, after the Clean Air Act (1970) and Clean Water Act (1972) were enacted, the heavy metal and ferrimagnetic concentrations decreased to present-day. The study supports that more developed land cover and impervious surfaces in a watershed lead to higher levels of anthropogenic related pollutants in fluvial systems. Sediment cores and aerial photographs from Lakes Butler and Litchfield indicate a history of both delta progradation and flood events. Studies, such as this, can assist in informing local policy makers and land managers when considering the effects of urban expansion, preservation of ecosystems and undeveloped spaces, and the effectiveness of national and local environmental regulations. v ACKNOWLEDGEMENTS Obtaining a master's degree is a long and arduous process, and aside from my own efforts, there were many people who helped me to reach this important goal. I first would like to extend speci...