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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Big Impact. Small Scale. Rethinking Water Aid for Hurricane Relief

Poarch, Patricia J. 14 October 2013 (has links)
No description available.
2

Spatial distribution of phosphorus in the sediments of a constructed wetland receiving treated sewage effluent

Rowley, Maxine Joy, University of Western Sydney, Hawkesbury, Faculty of Science and Technology January 1998 (has links)
The Byron Bay Sewage Treatment work consists of a conventional treatment system discharging into an 8 ha wetland. The wetland was constructed around the dune and swale remnants of a coastal beach ridge formation. The wetland design incorporated stands of broad leaf paperback, Melaleuca quinquenervia , in two distinct Sections, separated by, and each preceded by, open water Sections fringed by predominantly emergent macrophytes. Spatial and temporal patterns in sediment phosphorus concentrations were examined using sediment cores. Core consisted of three main sediment types - surface organic accumulation, pre-existing organic layers and sand. Results suggest that the design and management of wetland systems should be aimed at maximising the deposition of sediment (and associated phosphorus) and minimising subsequent phosphorus release from the sediment. This might be achieved through the removal of accumulated organic sediments to retain the phosphorus adsorption capacity of the system, consideration of wind direction during periods of high (floating) plant growth (as detritus may accumulate along the up-wind edges of the wetland), incorporation of deep zones to minimise sediment phosphorus release and the inclusion of stands of M. quinquenervia. Results highlight pitfalls in the prevailing approach to wetland design, which ignore the complex functions which occur in natural wetland systems. A more holistic approach incorporating a high diversity of ecozones in wetland design is proposed, in effect mimicking natural systems. / Master of Science (Hons)
3

Rip Channel Morphodynamics at Pensacola Beach, Florida

Labude, Daniel 14 March 2013 (has links)
80% of all lifeguard related rescues along the beaches of northwest Florida are believed to be related to rip currents. A rip current is the strong flow of water, seaward extending from the beach to the breaker line. It has previously been shown that there are rip current hot spots at Pensacola Beach, forced by a ridge and swale topography offshore, but the annual evolution/behavior of these hotspots (i.e. location, size, frequency, and orientation) have not been examined in detail. Remote imagery from Casino Beach was rectified to a planar view in order to examine the rip channel characteristics. These characteristics were analyzed to determine variations and patterns on a daily, monthly, and seasonal basis and in relation to reset storms, wind and wave characteristics, and the beach states of Casino Beach in order to characterize the rip development and variation throughout a year. Beach states and rip configurations were impacted by many frontal storms and one tropical storm, which were classified as a reset storm when reconfigurations of the beach state and rips occurred. Given sufficient time between reset storms, the bar migrated onshore in a manner consistent with the Wright and Short (1984) model, transitioning from LBT, to RBB, and finally to TBR state. The lack of reset storms after March 2010 resulted in a large frequency of observed rip channels (64) between April and May. It is shown that these rip channels are clustered into 7 statistically significant groups based on their location alongshore at the 95 % confidence interval. It is argued that the rip channel clusters are a direct result of the wave forcing caused by the ridge and swale topography. This situation causes the bar to move onshore that without interruption of a reset storm will attach at certain locations creating a transverse bar and rip morphology. The bar appears to attach to the beach at consistent locations throughout the year creating similar rip locations and subsequently the rip clusters. The risk posed to beach users by these rip currents is concentrated in certain locations which are persistent throughout the year.
4

Sorption of Stormwater Pollutants for Five Material Mixtures: A batch Equlibrium Study

Rydholm, Fredrik January 2021 (has links)
Blue-green infrastructure have been more lucrative during the last 30 years, since urbanizationbrings more impervious surfaces that increases stormwater runoff volumes. Amongst thedifferent blue-green infrastructures there are e.g., constructed wetlands and swales. Blue-greeninfrastructure means more natural management of the stormwater, such as infiltration. Forinfiltration of water, the hydraulic conductivity is an important parameter, but also the abilityto remove dissolved pollutants. In literature, various studies of filter materials are only testedfor single dissolved pollutants, which might be a disadvantage as this does not represent fieldconditions where metals usually co-exist. Economic costs are also an important parameter,unfortunately not always targeted in research. In this thesis, the efficiency of five different material mixtures for removing typical dissolvedstormwater pollutants: chromium (Cr), copper (Cu), nickel (Ni), phosphorus (P), lead (Pb) andzinc (Zn) were studied. The mixtures were following: 1) crushed rock + soil (RO_SO) 2)crushed rock + soil + LECA 4/10 + biochar (RO_SO_BC_LC4). 3) crushed rock + soil + LECA10/20 + biochar (RO_SO_BC_LC10). 4) Soil (SO). 5) crushed rock + soil + biochar(RO_SO_BC). This study was a part of blue-green investments that is being made in Östersundmunicipality and the use of low-cost materials for stormwater treatment are examined. The study was made using batch equilibrium tests, to determine the sorption capacity fordifferent material mixtures, using dissolved metal- and P-solutions. The measured data werefitted to Freundlich, Langmuir, Temkin, Dubinin-Radushkevich and Redlich-Petersonisotherms. Economic feasibility has also been compared between the material mixtures.Results showed that SO had the best sorption capacity for all metals and P, with rankingPb > Cr > Cu > Ni > Zn for the metals. All material mixtures showed a removal efficiency of79-99%, at the lowest concentration (1mg/L) for the metals and 31-62% for the lowestconcentration of P-single solution (1mg/L). Using additional materials in the mixtures, such asbiochar, slightly improved the sorption capacities of Pb and P. Redlich-Peterson isothermsprovided the best fits to the data. An economic evaluation of the ingoing materials shows thatSO and RO_SO are undoubtedly the most feasible alternatives for removal of targeted metalsand P.
5

Potential Impact of Contour Bunds on Diclofenac Removal for Stormwater Control in Rangeland Applications

Whitehead, Braden Alan 01 September 2021 (has links) (PDF)
Diclofenac (DCF) and other emerging contaminants have been found in environments worldwide. These contaminants may enter the environment due to the application of treated wastewater, biosolids and direct excrement related to veterinary application. Leakage from the soils toward the groundwater is largely controlled by sorption and microbial degradation. Most studies on the environmental fate of DCF have focused on degradation during wastewater treatment processes. However, little is known about their behavior in soil. In this study, the combined effect of adsorption and degradation of diclofenac has been investigated in four (4) 24 ft3 agricultural soil-filled beds designed to mimic natural vegetated soil environments, enhanced via controlled wetting and drying cycles. Contour bund installation on slopes of 5, 10, 15 and 20° were mimicked in the beds. Results showed that the soil environment was a strong inhibitor to the leaching of DCF through the soil. Saturating slopes via contour bund application however can lead to landslides that may impact structures and human life. A feasible contour bund installation site was investigated and found that 20° slopes under saturated conditions resulted in an unsafe factor of safety and is not encouraged as a solution for stormwater management. The effect of contour bund application on slopes under 15° at the installation site can potentially increase removal of emerging contaminants, thereby protecting groundwater resources without endangering life or property.
6

Safe Haven Leveling the Playing Field by Creating a Home for the Unsheltered, Homeless, Water, and Native Plants

Mitchell, Michelle Lynn 13 January 2022 (has links)
Through natural and constructed elements, landscape architects design public landscapes to engage the public in the great outdoors. While many local governments and designers actively create landscapes to keep the unsheltered and homeless out of public spaces, keep water in storm drains, and keep native plants on the periphery of the public landscape, my project, Safe Haven, is about creating an inclusive public landscape for people, water, and native plants. Preliminary research into the history of property ownership, discrimination, economic inequality, and government programs for the unsheltered created a picture of why certain demographics struggle with housing. Case studies of homeless encampments in the Washington DC area of NOMA, Abbot's Camp in Austin, Texas, and car camping in San Diego, California, and Seattle, Washington, gave insight into the current landscape needs of unsheltered people. Studies of the watershed and plants native to the site inspired a water retention system and a seasonal pallet of plants. The design incorporates existing infrastructure, new buildings, a natural playground, wilderness camping, a Mount Vernon-inspired vegetable garden, and a sunken garden designed to retain water while showcasing native plants. Describing the design are narratives sharing the perspective of water, native plants, the unsheltered, and the homeless. Lady Landscape guides the stories and offers her views on the responsibilities of a landscape architect. / Master of Landscape Architecture / Inclusive landscapes create a vision of places where children, older adults, people with and without disabilities enjoy the beauty of Mother Nature. There are ADA regulations that ensure everyone can be accommodated within a public landscape, but those regulations don't extend to the needs of unsheltered or homeless people. Their needs to enjoy public parks and recreation areas are different from housed people. They're looking for a home, and many public spaces are built to deter them from living on public lands. My project is a landscape designed with the unsheltered and homeless as the primary client. My project is about creating room for people without homes in the landscape - offering them dignity and meeting them where they are. Researching the needs of the homeless and what is presently available helped guide my design. After choosing an appropriate site in Fairfax City, Virginia, it became apparent that water and native plants would also need a home in this project. A thorough study of the water pattern over the area informed design elements that gave water a home through a Vegetative Swale and Sunken Garden while native plants found space in garden rooms. The thesis is presented as a narrative with Lady Landscape guiding the reader through the design by introducing them to the people and natural elements the landscape offers refuge to.
7

English Place-Names from a Scandinavian Perspective : A study on place-names in Herefordshire, Cumbria and the areas reachable by Viking ship through the Humber / Engelska ortsnamn ur ett Skandinaviskt perspektiv : en studie av ortnamn i Herefordshire, Cumbria och de områden som var nåbara med vikingaskepp via Humber.

Kahnberg, Martin January 2021 (has links)
In an attempt to discern the prevalence of British place-names with a Scandinavian origin this paper is a small linguistic study on place-names in Herefordshire, Cumbria and the areas along rivers Trent and Ouse. Based on modern maps place-names were included in the study. Older forms of the place-names were retrieved, and these old forms were analysed in order to understand the modern versions of the place-names. Place-name elements were grouped and their frequencies calculated in an attempt to understand the distribution of elements in each area. 1300 place-names were categorised based on their presumed origin, though some lacked the necessary information. Several place-names were given new possible derivations based on their categorisation and the elements they contained. Modern place-name elements/features hinting at a possibly Scandinavian place-name in the past were identified and described. Possible geographical patterns of Scandinavian place-names were found in central Herefordshire, in south-eastern Cumbria and in north-western Yorkshire. Possible implications of the place-names and their geographical concentrations were considered, yielding a hint on an area that might have been pivotal in the evolution of Old English. / I ett försök att urskilja utbredningen av brittiska ortnamn med ett skandinaviskt ursprung är denna uppsats en liten språkvetenskaplig studie av ortnamn i Herefordshire, Cumbria och längs floderna Trent och Ouse. Utifrån moderna kartor i en viss upplösning inkluderades alla synliga ortnamn i områdena. Äldre versioner av ortnamnen samlades in, och dessa gamla former analyserades i syfte att undersöka bakgrunden till de moderna ortnamnsvarianterna. Ortnamnens delar grupperades och deras frekvenser beräknades i syfte att förstå hur dessa fördelades i de olika områdena. 1300 ortnamn kategoriserades utifrån deras förmodade ursprung, men några ortnamn saknade den nödvändiga information undersökningen krävde. Flera ortnamn fick nya tänkbara betydelser baserat på den kategori de tilldelats och de ortnamnsdelar de innehöll. Moderna ortnamnsdelar som skulle kunna indikera en forntida nordisk ortnamnsvariant identifierades och beskrevs. Tänkbara geografiska nordiska ortnamnsmönster upptäcktes i centrala Herefordshire, i sydöstra Cumbria och i nordvästra Yorkshire. Tänkbara implikationer av ortnamnen och deras geografiska koncentrationer betraktades, vilket resulterade i upptäckten av ett område som kan ha påverkat fornengelskans utveckling i väldigt hög utsträckning.
8

Watershed-based design of stormwater treatment facilities : model development and applications

Larm, Thomas January 2000 (has links)
No description available.
9

Watershed-based design of stormwater treatment facilities : model development and applications

Larm, Thomas January 2000 (has links)
No description available.
10

INVENTORY OF STORMWATER MANAGEMENT PRACTICES IN THE CITY OF OXFORD, OHIO

Kitheka, Bernard M., Mr. 25 May 2010 (has links)
No description available.

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