Songlin Cheng (Advisor)
Master of Science (MS)
Geology and land use and land cover are the most important factors that influence water quality. The purpose of this study is to investigate how these factors operate in a rural watershed. Specifically, this thesis tests the feasibility of a proposed formula to relate how land use affects surface water quality and to infer hydrogeochemical reactions that control water chemistry through hydrogeochemical speciation and mineral stability relationships. Samples were collected from Indian Lake and its watershed in West-Central Ohio. BASINS, produced by the USEPA, was then used to delineate sub-watersheds and find the land use areas of these watersheds. The proposed formula was applied to find the land use impact coefficient of nitrate for various land covers. Due to data limitations only agricultural and forested land were able to be solved for. The land use impact coefficient for an agricultural area was 0.01-0.2 mg/l-acre. The land use impact coefficient for a forested area was solved using a series of linear equations and was approximately -0.06 to -0.01 mg/l-acre. This value indicates that agricultural is a source of nitrate and forests are sinks of nitrate. Several strong correlations, using a Pearson Correlation, were found including sodium and chloride indicating the application of road salt. Another correlation found was the relationship between calcium, magnesium and alkalinity. The correlation indicated a bedrock of limestone or dolomite, which is confirmed by the literature. Finally, a hydrogeochemical speciation was carried out to determine clay mineral stability. Kaolinite was found to be the dominant clay mineral in the watershed. Low silica concentration in all lake samples is most likely due to the uptake of silica by diatoms.
Department or Program
Department of Earth and Environmental Sciences
Year Degree Awarded
Copyright 2007, all rights reserved. This open access ETD is published by Wright State University and OhioLINK.