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Master of Arts / Geography / Charles W. Martin / Tuttle Creek Dam was built in 1962 after near-record flooding in the Kansas River watershed. It has been in operation for over 50 years. In that time, nearly half of its storage capacity has been filled by sediment, reducing its ability to serve its intended purpose under current operations. The Corps of Engineers authorized a study to examine the sediment in Tuttle Creek Lake and determine management strategies to extend its lifespan. This report examines the erodibility of the sediment as a function of depth and distance to dam. Eight sediment cores were tested and analyzed for two erodibility parameters, critical shear stress and erodibility coefficient. After directly comparing these parameters it was determined that Tuttle Creek Lake sediment ranges from erodible to very erodible regardless of depth or location. Analyzing for locational and depth patterns in erodibility coefficients indicated that both influence the erodibility of sediment, with depth being the stronger factor. These results indicate that locations further upstream from the dam and greater depths are the least erodible. Sedimentation patterns were mapped onto a three dimensional model in ArcMap. It is hoped that this research will assist Corps of Engineers leadership in deciding which management practices to pursue for Tuttle Creek Lake.

No description available.

A test facility was constructed to conduct experimental investigation of erosion caused by gas-borne ash particles. The test facility was used to carry out the main objective of the study which was the determination of the critical angle of attack that gives maximum erosion on the target material, mild steel, and the effect of particle velocity and concentration on the erosion of the target material. The tests were carried out using ash samples from three different Eskom fossil-fuelled power stations, namely Matimba Power Station, Matla Power Station and Lethabo Power Station. The selection of the ash samples was based on the ash chemical composition that has the highest content of the chemical elements that have a significant influence in the material erosion of the target material. These chemical elements are quartz and other abrasive materials. These ash samples had a high content of these erosive materials. The first test that was carried out in this study was the determination of the critical angle of attack that gives maximum erosion on the target material. It was decided to start by doing this test because the velocity and concentration tests needed a predefined critical angle of attack that gives maximum erosion on the target material. During the velocity and concentration tests the angle of attack was kept at the predefined critical angle of attack. The results in this study indicate that the critical angle of attack that gives maximum erosion on the target material is at 27º ± 3º orientation of the target surface. The velocity test results indicate that the material erosion rate increases with increasing velocity. The results produced a power relationship between erosion rate and velocity. In this power relationship the velocity exponent for the three ash samples was found to be in the range between 2.42 and 3.64. The concentration test results also indicate that the material erosion rate increases with increasing particle concentration. These results produced a linear relationship between erosion rate and particle concentration.

Orientador: Alexandre Marco da Silva / Banca: José Mauro Santana da Silva / Banca: Simone Andrea Furegatti / Resumo: A erosão dos solos é fenômeno natural que ocorre tanto em áreas rurais como urbanas, atuando através da remoção e arraste de material, tendo consequências muito sérias ocasionando diversas perdas financeiras e até de vidas humanas. A necessidade de conter ou controlar esse processo de degradação inspirou o desenvolvimento de várias tecnologias ligadas à área de bioengenharia. Duas delas, biomanta e hidrossemeadura, são atualmente vendidas separadamente no mercado provavelmente por razões comerciais, mas possuem o potencial de ser trabalhadas de maneira integrada. O objetivo do presente trabalho foi testar a eficácia do uso integrado de duas técnicas de controle de erosão causada pela água em encostas e taludes: biomanta e hidrossemeadura. O trabalho foi realizado no município de Sorocaba em um talude com forte pendente disponibilizado dentro do Campus da Faculdade de Tecnologia (FATEC). Foram usados materiais de baixo custo, além do uso de rejeitos de material proveniente de cortes de vegetação de baixo porte que muitas vezes não tem um destino adequado. Para tanto foram construídas oito parcelas retangulares de aproximadamente seis metros de extensão por um metro de largura. Duas destas parcelas foram mantidas continuamente descobertas (condição controle de terreno natural) e as outras seis foram cobertas / protegidas com mantas biodegradáveis, sementes ou sistema integrado de palha e sementes. Ao todo foram construídos quatro pares, cada um deles com uma técnica diferente d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Soil erosion is a natural phenomenon that occurs in rural and urban areas, acting through the removal and dragging of material, with very serious consequences causing several losses including human lifes. The need to contain or control this degradation process has inspired the development of several technological alternatives linked to the area of bioengineering. Two of them are currently sold separately on the market, probably for commercial reasons, but have the potential to be worked on in an integrated fashion. The aim of the present work is to test the effectiveness of two techniques integrated to avoid erosion caused by water on slopes used together: bio-blanket and hydroseeding. The work was carried out in Sorocaba in a slope with strong inclination made available within the Campus of the Faculdade de Tecnologia (FATEC). For the work, low cost materials were used as the litter usually coming from the tailings, vegetation cuts that often did not have an adequate destination. For this, eight rectangular plots of approximately six meters in length by a meter of width each were constructed. Two of these plots were kept continuously discovered (natural land control condition) and the other six were covered / protected with biodegradable blanket, seeds or integrated straw and seed system. Altogether there are four pairs compared, each with a different solution from the each other. During the research, the seedlings of the species that germinated were evaluated and quantified... (Complete abstract click electronic access below) / Mestre

This investigation looked at the climatic variables affecting the durability of earth buildings and the relationship between these climatic variables and their laboratory counterparts, with the aim of providing a means whereby performance in the field under known climatic conditions can be predicted by performance in the laboratory. The investigation showed that the major climatic factors influencing the erosion of earth walls due to wind-driven rain are impacting rainfall volume, drop impact velocity (as determined by wind conditions), raindrop size and duration of rainfall. A vertical rain gauge was calibrated with climatic conditions at a test site in Sydney to enable accurate prediction of the volume of water impacting test specimens. In the laboratory, a standard spray test was modified by introducing a commercially available nozzle, which produces a turbulent spray of individual drops, rather than a stream of water. Erosion rates using this apparatus were found to vary significantly with time, and a correction formula was derived from experimental results to enable comparison to be made between field and laboratory results. Erosion rates per unit volume of water were found to be proportional to impacting velocity raised to the power 2.5 and inversely proportional to the median drop diameter raised to the power 1.2. A material factor was defined as the 60 minute erosion mass loss divided by the 60 minute volume of impacting water spray. Field tests were carried out over a period of four years and analysed in relation to the associated laboratory test results. Laboratory testing was carried out on one half of split specimens, the other half being subjected to exposure to the weather at Sydney's International Airport, with regular monitoring of wind and rain records. An empirical model was developed and was used to compare field and laboratory results. This confirmed the importance of impacting volume of water and material factor but in this case the calculated correlation between field and laboratory erosions was not improved by the addition of impact velocity and drop size terms.

Siletz Bay is a drowned river valley filled with Holocene alluvial and estuarine sediments and is separated from the ocean by a sand spit 3.8 km in length. Since the area was settled by white man in the 1890's, the bay has apparently experienced rapid siltation, due to increased farming and logging. This along with the damming of the Siletz River sloughs has altered circulation patterns in the bay. Deflection of the Siletz River flow by the prograding Drift Creek delta has caused 105 m of erosion since 1912 on the east side of Siletz Spit. The ocean side of the spit suffers periodic erosional episodes separated by periods of accretion and dune building. The most recent and publicized erosion occurred during the winter of 1972-73 when it was feared that the spit might be breached; one partially constructed house was lost and three others were saved only by timely riprapping. A sand mining operation may have aggravated the recent erosion by disrupting the sand budget, the balance of sand additions and losses from the beach. All of the foredune on the spit has been stabilized by dune grass and much of it has been riprapped. The long term effects of stabilization and riprapping are uncertain. / Graduation date: 1975

Graduation date: 1997

Thesis (M.C.E.)--University of Delaware, 2006. / Principal faculty advisors: Nobuhisa Kobayashi and Jack Puleo, Dept. of Civil & Environmental Engineer. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 1983. / Typescript (photocopy). Includes bibliographical references (leaves 91-104). Also available on the World Wide Web.