Biology Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/2749
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Item EVALUATING RESTORATION POTENTIAL AND STORM SURGE ATTENUATION IN DITCHED AND UNDITCHED COASTAL MARSHES(2017) Lundberg, Dorothea June; Prestegaard, Karen; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The effects of ditching on the hydrological regime and ecosystem services of ditched coastal marshes—as well as the effects of hydrologic restoration of these systems—have yet to be extensively studied. The goals of this project were (1) to determine differences between ecohydrological processes in Ditched and Unditched coastal marshes, (2) to determine the effects of ditch plugging restoration projects on Atlantic Coast and Chesapeake Bay marsh hydrology, and (3) to evaluate Hurricane Sandy storm surge in the coastal marshes. Two separate pairs of Ditched and Unditched marshes were used in this study. The paired sites were adjacent, with similar topography, vegetation, and tidal patterns. Data collection included hydrological properties such as ditch density, tidal stage, water table fluctuations; as well as soil properties. Soil properties were similar in Ditched and Unditched marshes, while ditched marshes had lower water table elevations than Unditched marshes. Ditch plugging restoration partially restored the hydrological regime. A comparison of Chesapeake and Atlantic coastal marshes during Hurricane Sandy indicated similar storm surge elevations, but shorter durations of inundation at the Chesapeake Bay marshes when compared with the Atlantic marshes.Item EFFECTS OF CHANNEL MORPHOLOGY ON FLOODPLAIN INUNDATION AND SURFACE-GROUNDWATER INTERACTIONS IN AN URBAN WATERSHED(2011) Lundberg, Dorothea June; Prestegaard, Karen L.; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The purpose of this study is to evaluate groundwater-surfacewater interactions between a stream and the adjacent floodplain. The study site includes two reaches on Paint Branch Creek: an incised reach with inset gravel bars and a non-incised reach with active accretion of gravels bars onto the floodplain and off channel features. Topography, sediment grain size and hydraulic conductivity, groundwater head, and floodplain/channel characteristics were measured. Groundwater head data in gravel bars and adjacent floodplains were monitored for one year to determine seasonal variations in groundwater flow directions, rates, and to develop groundwater probability curves. Identification of groundwater-surfacewater interactions and off channel features roles was determined. In the reach with attached gravel bars, water flows from the creek into the adjacent gravel bars for the most of the year. Evapotranspiration and tropical storms influence seasonal reversals in flow directions between the gravel bar and the floodplain.