Master of Science, The Ohio State University, 1979, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science (MS), Ohio University, 2020, Environmental Studies (Voinovich)

This study investigated pollinator use across areas of the channelized Hocking River's banks in different stages of ecological succession, according to when each area last experienced a mowing disturbance. These successional stages of growth—an associated pollinator use—were compared according to each area's community structure using metrics such as diversity, leaf area index (LAI), greatest height, percentage of native plants, and percentage of noxious plants. Each successional stage was monitored over time to assess seasonal change in both vegetative growth and pollinator use. Each area was also evaluated for both actual and hypothetical roughness scenarios to determine what impact mowing regimes—and lack thereof—might have on flood potential. Considerations were given to past studies that examined community perceptions of the channelized river, as well as precipitation and flood trends. Ultimately, this study investigated whether alternative mowing practices could be socially, economically, and ecologically beneficial, without jeopardizing flood protection. The study concluded that the ecosystem service benefits of actively managed growth outweigh the risk of flooding in the channel. It recommends that further studies, including a review from the Army Corps of Engineers, be undertaken to begin the process of restoring the channelized Hocking River's riparian zone to a more sustainable and ecologically beneficial state.

Committee: Natalie Kruse Daniels Ph.D. (Advisor); Rebecca Snell Ph.D. (Committee Member); Amy Lynch Ph.D. (Committee Member) Subjects: Biology; Botany; Civil Engineering; Conservation; Ecology; Engineering; Entomology; Environmental Management; Environmental Science; Environmental Studies; Geography; History; Horticulture; Hydrologic Sciences; Hydrology; Landscape Architecture; Management; Plant Biology; Plant Sciences; Pollen; Wildlife Conservation; Wildlife Management

Doctor of Philosophy, The Ohio State University, 1977, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Master of Science (MS), Ohio University, 2015, Geography (Arts and Sciences)

Channel planform change of the Hocking River was documented over 75 years between Sugar Grove and Athens, Ohio, to determine whether any significant changes were associated with major human activities or selected physiographic variables in the watershed. Channel planform change was mapped by acquiring and analyzing aerial photographs and digitizing the channel in GIS. Planform variables of sinuosity, width, asymmetry, and channel migration were calculated. Of the studied human and environmental variables, human-induced changes through the advent of transportation infrastructure, specifically US Route 33, and channelization to mitigate property damage within the floodplain were the leading causes of significant planimetric change of the upper Hocking River over the 75-year span. Significant changes in sinuosity, width, and channel migration occurred directly in the modified reaches as well as the reach immediately downstream from a modification. Historic floods triggering meander cut-offs was the second most important variable affecting planimetric change. Finally, the percent change in riparian vegetation was shown to have a moderately negative correlation with percent change in channel width, while a correlation between percent change in riparian vegetation and rate of change in channel position was not found. Overall, while the upper Hocking River displayed natural planimetric variability over the study interval, the greatest impacts, both directly and indirectly, upon channel planform were associated with human modifications.

Committee: Dorothy Sack (Advisor); James Dyer (Committee Member); Timothy Anderson (Committee Member) Subjects: Earth; Geography; Geomorphology; Physical Geography; Water Resource Management

Master of Science in Environmental Science, Youngstown State University, 2014, Department of Physics, Astronomy, Geology and Environmental Sciences

Water is the human population's most scarce resource. Human impacts such as urbanization, agriculture and channelization have an effect on water and stream quality. Channelization, the straightening of streams to better fit human land use needs, was a common practice in northeast Ohio. While the channelization of streams is useful for agriculture and for other purposes, it is a major stress for natural aquatic systems. A 4 km-long (~2.5 miles) portion of Snyder Ditch, Orwell, NE Ohio, was channelized in the early 1900s for agricultural drainage. This study evaluates stream quality of this channelized system utilizing water chemistry, macroinvertebrate diversity studies and stream habitat assessment. Stream quality was compared against Ohio EPA stream use designation of warmwater habitat for three sampling dates: May, August and October 2013. It was initially hypothesized that stream quality would not reach warmwater habitat standards, as designated by the Ohio EPA. The results surpassed the original expectation of the stream; however, still did not reach warmwater habitat designation criteria. Dissolved oxygen levels were near the required 5 mg/L with most of the sampling dates having low levels of nutrients (nitrate, phosphate and ammonia). There was good overall diversity and density of macroinvertebrates and a higher than anticipated number of pollution sensitive taxa. The largest difference in stream quality was due to the stream habitat or lack thereof. Areas that contained some stream sinuosity, better substrate or more diverse riparian area had better density and diversity of macroinvertebrates. Therefore, with some habitat alterations or restoration, the stream quality has the potential to improve to warmwater criteria. This work, in addition to other ongoing projects, may lead to a better understanding of environmental parameters at this site, which would help land-owners develop better strategies for land management and restoration.

Committee: Felicia Armstrong Ph.D. (Advisor); Thomas Diggins Ph.D. (Committee Member); C.Robin Mattheus Ph.D. (Committee Member); Alex Czayka (Committee Member) Subjects: Ecology; Environmental Science

Master of Science in Engineering (MSEgr), Wright State University, 2007, Electrical Engineering

Wideband digital receivers are important components used prevalently by the United States Air Force for many modern electronic warfare systems. Currently, many digital receiver architectures are designed for a specific mission requirement and are not parameterizable, modular, or reusable for varying mission requirements. Also, many designs are technology, platform, and vendor dependent which make upgrading existing fielded systems costly and difficult. Additionally, current wideband FFT-based digital receivers must wait until a number of samples equal to the size of the FFT are collected before spectral information can be updated. Achieving a high spectral update rate is important for the accurate detection of the time of arrival of radar pulses so that enemy signals can be detected and located quickly. Current methods to increase the effective spectral update rate by N require an N-fold increase in clock rate or an N-fold increase in area. For this research, a parameterizable channelized wideband digital receiver architecture is proposed that takes advantage of the tradeoffs between frequency resolution and spectral update rate while preserving bandwidth, reducing hardware requirements, and increasing throughput. The design is completely parameterizable to suit varying mission requirements, and it has been written in generic VHDL which was targeted toward FPGA and ASIC platforms with no code modification. Components developed in VHDL include the decimation filter and Parks-McClellan filter design algorithm. The FPGA implementation was fully tested, and for the parameters chosen, was able to achieve an 8x improvement in update rate.

Committee: John Emmert (Advisor) Subjects:

Doctor of Philosophy, The Ohio State University, 2011, Electrical and Computer Engineering

With the rapid development of wireless communication systems and increasing wireless communication applications in human life, more and more new communication standards are proposed, which introduce additional frequency bands or modulation schemes. The growing number of wireless communication systems and the increasing demands for bandwidth necessitate the evolvable receiver hardware. To meet this requirement, this work proposes a digitally controlled channelized Software Defined Radio (SDR) architecture which is compatible with most applications in 0.5-10.5 GHz frequency range. In the proposed SDR, the digitally controlled channelized front end divides the entire frequency into seven 1.6 GHz sub bands, and further channelization is realized using a digital filter bank structure so that the proposed SDR could deal with both ultra-wideband and narrow band signals. Link-Budget analysis is performed in the system design, and the detailed specifications for the front end signal processing blocks is provided. A system simulation is performed in ADS to verify the proposed SDR. The circuit design considerations for the proposed SDR system is discussed. The major characteristics of the SDR front end are its ultra-wideband spectrum access, software programmability, and its ability for digitally controlled channelization. The circuit design discussion is focused on those aspects, and gives an idea of some possible design techniques or circuit structures which may be used for the proposed SDR system. Using those techniques, specific circuits are designed as examples, including an LNA with tunable output frequency, an active mixer design with extended IF bandwidth, as well as a quadrature coupler structure with ultra wideband operating frequency range. The simulated results for each circuit block are presented, and the proposed techniques are verified.

Committee: Joanne DeGroat (Advisor); Mohammed Ismail (Committee Member); Steven Bibyk (Committee Member) Subjects: Electrical Engineering

Master of Arts (MA), Ohio University, 2008, Geography (Arts and Sciences)

Channel planform change was investigated along 24 kilometers of the Hocking River in Athens County, Ohio, by overlaying aerial photographs spanning 67 years into a geographic information system (GIS) to observe temporal and spatial stream patterns before and after the Army Corps of Engineers modified the river to control flooding in the city of Athens. Previous research has suggested that artificial channel adjustments alter the fluvial geomorphology in the downstream direction by increasing stream volume and stream velocities, causing erosion of the channel and lateral migration of a stream.Channel planform mapping was accomplished through digitizing the fluvial features of a stream and measuring the rates of change. The changes that were observed by the GIS-based methodology show statistically significant changes in the Hocking River channel widths, but little change in lateral migration, except in the asymmetry of meanders bends. Changes in channel width gradually decrease with distance. This lack of change in position and downstream decrease in width suggest that the channelization did not have much impact on the channel planform.

Committee: Dorothy Sack (Committee Chair); James Lein (Committee Member); Margaret Pearce (Committee Member) Subjects: Geography

Master of Science (MS), Ohio University, 2005, Environmental Studies (Arts and Sciences)

In southeastern Ohio, people (authorities, institutions, governments) in the late 1960s decided to change part of the course of the Hocking River and make it flow in an artificial channel. This thesis investigates how people perceive the channelization of the Hocking River. A qualitative study was performed in order to achieve the objectives of this research using interviews. Thirty people participated in 25 interviews. Thirteen themes emerged from the interviews. The themes are classified as pertaining primarily to the physical environment or to human-environmental interaction. Limitations to this study exist because of the relatively small number of people surveyed, the convenience-based sampling strategy, and the fact that all but two of the interviewees were over 50 years old. The results of this investigation show that the perception of people may vary according to the personal interest, the education, and the environmental knowledge of the interviewees. Overall, the people appreciate its role in flood control even though it may no longer be as effective as it once was or as effective as it was supposed to be at the time of initial planning. This flood protection in Athens, moreover, is probably increasing flood hazards downstream. Many people think the expansion of the commercial area of Athens on the floodplain has had a positive economic effect, although a significant minority point out negative economic and community effects related to establishment of the large national franchise stores in town. It is ironic that this floodplain development is encroaching on the channelized river because the artificial channel was purposefully located away from such buildings as part of the flood protection measures. Flooding will never be totally controlled, thus property damage from floods will result as long as floodplains are used for human activities. Constructing the channel destroyed much of the attractive appeal of Athens, which included extensive gardens that were (open full item for complete abstract)

Committee: Dorothy Sack (Advisor) Subjects: Environmental Sciences

Master of Arts, Miami University, 2008, Geography

This study focuses on two Ohio reservoirs. The Delaware, with large increases in sedimentation rates in recent years and the O'Shaughnessy, with decreases. The questions I sought to answer were 1) what are the watersheds' landscape/land use characteristics and have they changed, 2) is there evidence of recent channel enlargement, and 3) what are the sources of reservoir sediment? I examined impervious surfaces, developed area change, topography, soils, ditched streams, precipitation, and flooding. I found the watersheds are similar in most characteristics, but differ in flooding and channelized stream distribution. Channels are deeper and channel material is the dominant sediment source in the Delaware, while surface material is the dominant source in the O'Shaughnessy. Decreases in O'Shaughnessy sedimentation rates are likely due to improvement in agricultural practices and increased sedimentation in the Delaware is attributable to subtle differences in the watersheds; likely channelization plays an important role.

Committee: William Renwick PhD (Advisor); Robbyn Abbitt Ms (Committee Member); Jerry Green PhD (Committee Member) Subjects: Environmental Science; Geography; Soil Sciences

Master of Landscape Architecture, The Ohio State University, 2013, Landscape Architecture

An increase in the understanding of anthropogenic impacts related to our waterways has spurred much interest in ecological stream restoration. Billions of dollars are entering this field as societal and regulatory pressures are exerted upon municipalities and developers. Research suggests that stream restoration projects only consider aesthetics and economic growth as key goals rather than thinking of how the stream functions holistically or ecologically. Additionally, research suggests that these funds are greatly misused, funding only stream restoration projects where space, politics, and infrastructure allow (Nilsson et al 2003, and Niezgoda and Johnson 2005). These projects cater toward a naturalized condition. A variety of techniques and strategies are deployed to achieve both project goals and objectives. These techniques and strategies support the notion of a naturalized stream condition through their effective use and aesthetics. Furthermore, research shows that goals and objectives for these projects can be lumped in to four main categories: bank stabilization, erosion control, stormwater management, and re-vegetation (Bernhardt and Palmer 2007). However, little is being done by way of research and design study in the most severely degraded portions of these streams—those that are concretized. The goal of this study is to show how restoration might occur in concretized waterways where a naturalized condition cannot fully accommodate the degree of changes and demands that have been placed on the watershed by urbanization. Objectives within this study focus on improvements to water quality and in-stream habitat as well as accessibility and connectivity for communities. Through the review of traditional stream restoration techniques, their hybridization, and deployment in concretized streams this project shows how a highly degraded stream condition can be augmented to perform similarly, ecologically, to its naturalized counterpart. A catalo (open full item for complete abstract)

Committee: Jacob Boswell (Committee Chair); Deborah Georg (Committee Member) Subjects: Landscape Architecture