+publisher:"Colorado State University" +contributor:("Ettema, Robert")

Colorado State University

1. Armstrong, Dylan L. Bed sediment transport and channel morphology in a braided channel: insights from a flume experiment.

Degree: MS(M.S.), Civil and Environmental Engineering, 2017, Colorado State University

URL: http://hdl.handle.net/10217/181441

► This thesis presents the methods and findings from an experiment aimed at relating the rate of bed-sediment transport through a reach of a braided channel… (more)

Subjects/Keywords: flume study; sediment transport; morphology; braided channel

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APA (6^th Edition):

Armstrong, D. L. (2017). Bed sediment transport and channel morphology in a braided channel: insights from a flume experiment. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/181441

Chicago Manual of Style (16^th Edition):

Armstrong, Dylan L. “Bed sediment transport and channel morphology in a braided channel: insights from a flume experiment.” 2017. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/181441.

MLA Handbook (7^th Edition):

Armstrong, Dylan L. “Bed sediment transport and channel morphology in a braided channel: insights from a flume experiment.” 2017. Web. 12 Apr 2021.

Vancouver:

Armstrong DL. Bed sediment transport and channel morphology in a braided channel: insights from a flume experiment. [Internet] [Masters thesis]. Colorado State University; 2017. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/181441.

Council of Science Editors:

Armstrong DL. Bed sediment transport and channel morphology in a braided channel: insights from a flume experiment. [Masters Thesis]. Colorado State University; 2017. Available from: http://hdl.handle.net/10217/181441

Colorado State University

2. Siefken, Seth. Computational fluid dynamics models of Rio Grande bends fitted with rock vanes or bendway weirs.

Degree: MS(M.S.), Civil and Environmental Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/197259

► Rock vanes (also known as stream barbs) and bendway weirs are two types of transverse rock structures used to modify the flow field in river… (more)

▼ Rock vanes (also known as stream barbs) and bendway weirs are two types of transverse rock structures used to modify the flow field in river bends. This study examines the effectiveness of the two types of structures at reducing velocity along the outer bank of river bends to protect the bank from erosion. A numerical model using the commercially available FLOW-3D software was used to evaluate the effect of various rock vane and bendway weir configurations on the flow field through two river bends typical of the Middle Rio Grande. The model was calibrated and validated using data from a previous physical model study of rock vanes. 33 different rock vane configurations were tested in the numerical model to evaluate the effect of altering planform angle, crest slope, projected length, and structure spacing. In addition, 14 different bendway weir configurations were tested to provide a comparison of the relative performance of bendway weirs and rock vanes. The numerical modeling results indicate that rock vanes are more effective at reducing the velocity along the outer bank of a bend than bendway weirs. Modelling showed that the completely submerged crest of bendway weirs allows a substantial amount of flow to pass over the crest, limiting their effectiveness in reducing velocity along the bank. In contrast, rock vanes, with a sloped crest intersecting the waterline at the design flow rate, directed more flow around the tip of the structure rather than over the crest and were much more effective at reducing velocity along the bank. Based on the modeling results, it is recommended that bendway weirs not be installed for the purpose of erosion protection along riverbanks. The reduction in velocity along the bank produced by the various rock vane configurations varied considerably with the geometry of the configuration. Based on the results, the following conclusions are made regarding rock vane geometry: (1) Rock vanes should be installed at a planform angle between 45° and 90° to the river bank. (2) There exists an optimal projected length of rock vane, which lies in the neighborhood of 1/5 to 1/3 of the channel top-width. (3) Rock vanes with a 10% crest slope perform well, although decreasing the crest slope will decrease the velocity along the outer bank and vice versa. (4) Decreasing the spacing of rock vanes decreases the velocity along the outer bank, up to a limit. A design equation was developed to predict the velocity reduction along the bank of a river bend produced by a given configuration of rock vanes, based on the geometry of the rock vanes and the river channel. The equation provided good predictions for the range of configurations tested, having a coefficient of determination r2 = 0.83 and predicting the velocity reduction along the outer bank to within 15 percentage points for all of the tested configurations. Advisors/Committee Members: Ettema, Robert (advisor), Thornton, Christopher (committee member), McGrath, Daniel (committee member).

Subjects/Keywords: bendway weirs; erosion protection; stream barbs; computational fluid dynamics; bank stabilization; rock vanes

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APA (6^th Edition):

Siefken, S. (2019). Computational fluid dynamics models of Rio Grande bends fitted with rock vanes or bendway weirs. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/197259

Chicago Manual of Style (16^th Edition):

Siefken, Seth. “Computational fluid dynamics models of Rio Grande bends fitted with rock vanes or bendway weirs.” 2019. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/197259.

MLA Handbook (7^th Edition):

Siefken, Seth. “Computational fluid dynamics models of Rio Grande bends fitted with rock vanes or bendway weirs.” 2019. Web. 12 Apr 2021.

Vancouver:

Siefken S. Computational fluid dynamics models of Rio Grande bends fitted with rock vanes or bendway weirs. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/197259.

Council of Science Editors:

Siefken S. Computational fluid dynamics models of Rio Grande bends fitted with rock vanes or bendway weirs. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/197259

Colorado State University

3. Biethman, Blake W. Air concentration and bulked flow along a curved, converging stepped chute.

Degree: MS(M.S.), Civil and Environmental Engineering, 2020, Colorado State University

URL: http://hdl.handle.net/10217/208447

► This thesis focuses on the air-entrainment performance of a stepped spillway of unique form. The performance was determined using a hydraulic model constructed at a… (more)

▼ This thesis focuses on the air-entrainment performance of a stepped spillway of unique form. The performance was determined using a hydraulic model constructed at a length scale (prototype length/model length) of 24. The new stepped spillway is part of the Gross Reservoir Expansion (GRE) project, which by 2025 is expected to raise the existing Gross Dam about a third of its current height. The stepped spillway will be the tallest stepped spillway in the United States. The model spillway consisted of a chute whose step dimensions, vertical to horizontal, were 0.051 m by 0.025 m, resulting in a chute slope (V:H) of 2.0 and a chute angle of 63.4°. Additionally, the chute conformed, in planform, to the curved planform of raised Gross Dam. At the spillway's crest, that radius of curvature, at model scale, was 22.2 m. The chute width converged by about 20% from the top of the chute to the stilling basin at the base of the chute. The chute's steepness, height, curvature and convergence made the chute's geometry unique among existing stepped spillways. The evaluation involved measurements of air entrainment and flow velocity along the stepped chute, for which the skimming flow regime prevailed for discharge larger than about 9% of the spillway's design discharge. To date, the effect on water flow and air entrainment of chute curvature in stepped spillways had not been investigated. The investigation was facilitated from measurements obtained using a dual-tip conductivity probe, which detected the instantaneous void fraction of the air-water mixture. The probe also enabled measurement of the velocity of the bulked flow along the chute. The study showed that, when the chute conveyed the design discharge (at model scale, 0.347 m3/s), streamwise values of air concentration and flow depth (bulked with entrained air) were basically constant near the bottom of the chute. Additionally, the chute's planform curvature resulted in non-uniform flow across the chute. At the design discharge, and near the bottom of the chute, the flow depth along the chute's centerline was nominally about 30% greater than the flow depth at the sidewall. When the chute's curvature was accounted for, the water surface along the centerline of the chute was approximately level with the water surface near the sidewall. Further, the depth-averaged concentration of entrained air near the bottom of the chute decreased with increasing water discharge. The chute's converging sidewalls mildly affected the flow near the sidewalls, causing slight increases in flow depth and reductions in flow velocity. These changes, though noticeable, were negligible in terms of spillway performance because of their magnitude. Advisors/Committee Members: Ettema, Robert (advisor), Thornton, Christopher (advisor), Wohl, Ellen (committee member).

Subjects/Keywords: bulked flow; converging; stepped chute; conductivity probe; air concentration; curved

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APA (6^th Edition):

Biethman, B. W. (2020). Air concentration and bulked flow along a curved, converging stepped chute. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/208447

Chicago Manual of Style (16^th Edition):

Biethman, Blake W. “Air concentration and bulked flow along a curved, converging stepped chute.” 2020. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/208447.

MLA Handbook (7^th Edition):

Biethman, Blake W. “Air concentration and bulked flow along a curved, converging stepped chute.” 2020. Web. 12 Apr 2021.

Vancouver:

Biethman BW. Air concentration and bulked flow along a curved, converging stepped chute. [Internet] [Masters thesis]. Colorado State University; 2020. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/208447.

Council of Science Editors:

Biethman BW. Air concentration and bulked flow along a curved, converging stepped chute. [Masters Thesis]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/208447

Colorado State University

4. Garfield, Mason. Effects of scour on the flow field at a bendway weir, The.

Degree: MS(M.S.), Civil and Environmental Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/197324

► Bendway weirs (BWs) are rock structures commonly used for controlling the thalweg location in alluvial channels, especially bends. Although there are many studies analyzing the… (more)

▼ Bendway weirs (BWs) are rock structures commonly used for controlling the thalweg location in alluvial channels, especially bends. Although there are many studies analyzing the effect of BWs on bend flow fields, there is little known about the effects of scour on the modified flow field. Many physical and numerical models of BWs use a fixed bed with the existing river bathymetry, assuming that the effects of scour are negligible. This study analyzed the effects of the scour on the flow field using SRH-2D, a 2-dimensional numerical model solving the full St. Venant equation (also termed the dynamic wave equation). In addition, the study used small scale and large scale hydraulic models and a 3-dimensional numerical model, FLOW-3D, to validate and calibrate the 2-D model. Using FLOW-3D, the 3-dimensional flow field was used to identify areas where SRH-2D was accurate and where it was lacking. The small scale hydraulic model was used to determine the effect of streamwise blockage on scour using plates. Results from the small scale hydraulic model indicate that when the degree of streamwise blockage (L/B where L is the width of the plate and B is the width of the flume) and submergence (Y/H where Y is the flow depth and H is the height of the plate) remained the same, but the acute angle to the flume wall varied (α), the maximum scour depth did not change significantly. Accordingly, the scour morphology from the tests with α = 90° could be applied to tests with α = 30° and 60° using the 2-D model. When comparing the flow field using SRH-2D to FLOW-3D, it was found that the maximum depth-averaged velocity was closer to FLOW-3D's when Y/H = 1.25 than when Y/H = 2.0. This finding likely results from the greater effect of blockage directing the flow around the BW than the deeper case, where the flow has a higher vertical velocity over the top of the BW. The 2-D model cannot take this into account, leading to error. The pre- and post-scour maximum velocity magnitude and locations were compared to determine the effect of scour on the flow field using the 2-D model. A deep flow depth (Y/H = 2.0) and a shallower flow depth (Y/H = 1.25) were run for different BW orientations, (α=30°,60°,and 90°) to determine the applicability of the effect of scour on the flow field. The analysis found that, when Y/H = 2.0, the difference in the maximum velocity magnitude and location between pre-and post-scour were fairly negligible for all orientations, whereas when Y/H =1.25, the effects of the scour on the flow field were more prominent. Overall it was found that the scour morphology is important to take into consideration for a fixed bed numerical or physical model when analyzing flow depths slightly overtopping the BW, but has little effect when the flow is twice the size of the BW. Advisors/Committee Members: Ettema, Robert (advisor), Thornton, Christopher (committee member), Wohl, Ellen (committee member).

Subjects/Keywords: FLOW-3D; SRH-2D; numerical modeling; bendway weirs

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APA (6^th Edition):

Garfield, M. (2019). Effects of scour on the flow field at a bendway weir, The. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/197324

Chicago Manual of Style (16^th Edition):

Garfield, Mason. “Effects of scour on the flow field at a bendway weir, The.” 2019. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/197324.

MLA Handbook (7^th Edition):

Garfield, Mason. “Effects of scour on the flow field at a bendway weir, The.” 2019. Web. 12 Apr 2021.

Vancouver:

Garfield M. Effects of scour on the flow field at a bendway weir, The. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/197324.

Council of Science Editors:

Garfield M. Effects of scour on the flow field at a bendway weir, The. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/197324

Colorado State University

5. Hogan, Taylor. Effects of bend radius on flow around a configuration of bendway weirs: insight from a numerical model, The.

Degree: MS(M.S.), Civil and Environmental Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/197362

► Bendway weirs have been used and refined for decades by hydraulic engineers to control thalweg location within alluvial rivers and to decrease flow velocity along… (more)

▼ Bendway weirs have been used and refined for decades by hydraulic engineers to control thalweg location within alluvial rivers and to decrease flow velocity along the outer bank of channel bends. Although these structures have been used in a variety of applications, there are still a wide range of acceptable design parameters that vary in accordance with the specific design methodology being used. Since the early 2000s, Colorado State University's Hydraulics Lab has assisted The U.S Bureau of Reclamation (USBR) in refining the design of bendway weirs and similar in-stream rock structures. During this period of time, Colorado State University and The USBR have utilized hydraulic and numerical models to develop systematic design guidelines for bendway weirs and other in-stream rock structures. Hydraulic modeling has also provided a large database of velocity and water surface measurements that have been used to calibrate and validate subsequent numerical models. The partnership between Colorado State University and the USBR has led to design recommendations and equations in which the effect of many variables and their sensitivity in overall bendway weir design has been identified. This study investigates the parameter radius of curvature over channel top width, Rc/Tw, and its effect on the flow field around bendway weirs, as its significance in bendway weir design is not well known. To investigate the effects of Rc/Tw on the bendway weir flow field, the 2D numerical model SRH-2D was used in conjunction with AutoCAD Civil3D software. The SRH-2D model was created using the bathymetry of the hydraulic model and then also calibrated and validated using data collected in the hydraulic model. AutoCAD Civil3D was used to create four different bend radii while holding Tw constant, representing Rc/Tw values between 3.0 and 8.0 which are typical of the Middle Rio Grande that the hydraulic model represented. Two additional trapezoidal channel models were also created to isolate the possible effects from specific channel geometry on the bendway weir flow field comparisons. 2D numerical modeling results revealed that the bend radius of curvature had negligible effect on the bendway weir flow field. Velocity patterns in the trapezoidal and native bathymetry channels changed negligibly in location and magnitude across varying bend radii. Cross-sectional velocity distributions were also evaluated and showed that the inner and middle third lateral sections of the channel showed the same (within fractions of a percent) velocity increase after the installation of bendway weirs. The outer fifth of the channel resulted in 6% velocity decrease only varying approximately 0.1% between bend radii. Overall numerical modeling results showed that the bendway weir flow field was negligibly affected by the bend radius of curvature, Rc. Advisors/Committee Members: Thornton, Christopher (advisor), Ettema, Robert (advisor), Williams, John (committee member).

Subjects/Keywords: change of bend radius; bendway weirs; SRH-2D

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APA (6^th Edition):

Hogan, T. (2019). Effects of bend radius on flow around a configuration of bendway weirs: insight from a numerical model, The. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/197362

Chicago Manual of Style (16^th Edition):

Hogan, Taylor. “Effects of bend radius on flow around a configuration of bendway weirs: insight from a numerical model, The.” 2019. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/197362.

MLA Handbook (7^th Edition):

Hogan, Taylor. “Effects of bend radius on flow around a configuration of bendway weirs: insight from a numerical model, The.” 2019. Web. 12 Apr 2021.

Vancouver:

Hogan T. Effects of bend radius on flow around a configuration of bendway weirs: insight from a numerical model, The. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/197362.

Council of Science Editors:

Hogan T. Effects of bend radius on flow around a configuration of bendway weirs: insight from a numerical model, The. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/197362

Colorado State University

6. Ubing, Caroline. Baffle-post structures for flow control in open channels.

Degree: MS(M.S.), Civil and Environmental Engineering, 2015, Colorado State University

URL: http://hdl.handle.net/10217/166972

► This thesis presents theory and laboratory findings regarding the hydraulic performance of baffle-post structures used as a means for controlling flow in open channels. Such… (more)

Subjects/Keywords: grade control structures; hydraulic structures; flow control; sediment transport; head loss coefficient

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APA (6^th Edition):

Ubing, C. (2015). Baffle-post structures for flow control in open channels. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/166972

Chicago Manual of Style (16^th Edition):

Ubing, Caroline. “Baffle-post structures for flow control in open channels.” 2015. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/166972.

MLA Handbook (7^th Edition):

Ubing, Caroline. “Baffle-post structures for flow control in open channels.” 2015. Web. 12 Apr 2021.

Vancouver:

Ubing C. Baffle-post structures for flow control in open channels. [Internet] [Masters thesis]. Colorado State University; 2015. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/166972.

Council of Science Editors:

Ubing C. Baffle-post structures for flow control in open channels. [Masters Thesis]. Colorado State University; 2015. Available from: http://hdl.handle.net/10217/166972

Colorado State University

7. O'Brien, Patrick S. Framework for the analysis of coastal infrastructure vulnerability under global sea level rise, A.

Degree: PhD, Civil and Environmental Engineering, 2017, Colorado State University

URL: http://hdl.handle.net/10217/185711

► The assumption of hydrologic stationarity has formed the basis of coastal design to date. At the beginning of the 21st century, the impact of climate… (more)

▼ The assumption of hydrologic stationarity has formed the basis of coastal design to date. At the beginning of the 21st century, the impact of climate variability and future climate change on coastal water levels has become apparent through long term tide gauge records, and anecdotal evidence of increased nuisance tidal flooding in coastal areas. Recorded impacts of global sea rise on coastal water levels have been documented over the past 100 to 150 years, and future water levels will continue to change at increasing, unknown rates, resulting in the need to consider the impacts of these changes on past coastal design assumptions. New coastal infrastructure plans, and designs should recognize the paradigm shift in assumptions from hydrologic stationarity to non-stationarity in coastal water levels. As we transition into the new paradigm, there is a significant knowledge gap which must address built coastal infrastructure vulnerability based on the realization that the underlying design assumptions may be invalid. A framework for the evaluation of existing coastal infrastructure is proposed to effectively assess vulnerability. The framework, called the Climate Preparedness and Resilience Register (CPRR) provides the technical basis for assessing existing and future performance. The CPRR framework consists of four major elements: (1) datum adjustment, (2) coastal water levels, (3) scenario projections and (4) performance thresholds. The CPRR framework defines methodologies which: (1) adjust for non-stationarity in coastal water levels and correctly make projections under multiple scenarios; (2) account for past and future tidal to geodetic datum adjustments; and (3) evaluate past and future design performance by applying performance models to determine the performance thresholds. The framework results are reproducible and applicable to a wide range of coastal infrastructure types in diverse geographic areas. The framework was applied in two case studies of coastal infrastructure on the east and west coasts of the United States. The east coast case study on the Stamford Hurricane Barrier (SHB) at Stamford CT, investigated the navigation gate closures of the SHB project. The framework was successfully applied using two performance models based on function and reliability to determine the future time frame at which relative sea level rise (RSLR) would cause Navigation Gate closures to occur once per week on average or 52 per year. The closure time analysis also showed the impact of closing the gate earlier to manage internal drainage to the Harbor area behind the Stamford Hurricane Barrier. These analyses were made for three future sea level change (SLC) scenarios. The west coast case study evaluated four infrastructure elements at the San Francisco Waterfront, one building and three transportation elements. The CPRR framework applied two performance models based on elevation and reliability to assess the vulnerability to flooding under four SLC scenarios. An elevation-based performance model determined a time horizon for… Advisors/Committee Members: Julien, Pierre Y. (advisor), Watson, Chester C. (committee member), Ettema, Robert (committee member), Rathburn, Sara L. (committee member).

Subjects/Keywords: coastal engineering; reliability; vulnerability assessments; coastal infrastructure; climate change; sea level change

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APA (6^th Edition):

O'Brien, P. S. (2017). Framework for the analysis of coastal infrastructure vulnerability under global sea level rise, A. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/185711

Chicago Manual of Style (16^th Edition):

O'Brien, Patrick S. “Framework for the analysis of coastal infrastructure vulnerability under global sea level rise, A.” 2017. Doctoral Dissertation, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/185711.

MLA Handbook (7^th Edition):

O'Brien, Patrick S. “Framework for the analysis of coastal infrastructure vulnerability under global sea level rise, A.” 2017. Web. 12 Apr 2021.

Vancouver:

O'Brien PS. Framework for the analysis of coastal infrastructure vulnerability under global sea level rise, A. [Internet] [Doctoral dissertation]. Colorado State University; 2017. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/185711.

Council of Science Editors:

O'Brien PS. Framework for the analysis of coastal infrastructure vulnerability under global sea level rise, A. [Doctoral Dissertation]. Colorado State University; 2017. Available from: http://hdl.handle.net/10217/185711

8. Yang, Chun-Yao. Sediment yield of South Korean rivers, The.

Degree: PhD, Civil and Environmental Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/195392

► South Korea is experiencing increasing river sedimentation problems, which requires a reliable method to predict the sediment yield. With the recent field measurements at 35… (more)

▼ South Korea is experiencing increasing river sedimentation problems, which requires a reliable method to predict the sediment yield. With the recent field measurements at 35 gaging stations in South Korea provided by K-water, we quantified the sediment yield by using the flow duration curve and sediment rating curve. The current sediment yield models have large discrepancies between the predictions and measurements. The goal of this dissertation is to provide better understanding to the following questions: (1) How much of the total sediment load can be measured by the depth-integrated samplers? (2) Can we predict the sediment yield based only on watershed area? (3) Is there a parametric approach to estimate the mean annual sediment yield based on the flow duration curve and sediment rating curve? With 1,962 sediment discharge measurements from the US D-74 sampler, the total sediment discharge is calculated by both the Modified Einstein Procedure (MEP) and the Series Expansion of the Modified Einstein Procedure (SEMEP). It is concluded that the SEMEP is more accurate because MEP occasionally computes suspended loads larger than total loads. In addition, SEMEP was able to calculate all samples while MEP could only compute 1,808 samples. According to SEMEP, the ratio Qm/Qt of measured sediment discharge Qm to total sediment discharge Qt is a function of the Rouse number Ro, flow depth h, and the median grain size of the bed material d50. In Korean sand and gravel bed rivers, the materials in suspension are fine (silt or clay) and Ro ≈ 0. The ratio Qm/Qt reduces to a function of flow depth h, and at least 90% of the total sediment load is measured when h > 1 m. More than 80% of the sediment load is measured when the discharge Q is larger than four times mean annual discharge ¯Q(Q/¯Q > 4). The ratio Qs/Qt of suspended sediment discharge Qs to total sediment discharge can be also analyzed with SEMEP and the result shows that Qs/Qt is a function of h/d50 and Ro. When Ro ≈ 0, the ratio Qs/Qt increases with h/d50. The suspended load is more than 80% of the total sediment load when h/d50 > 18. The relationship between specific sediment yield, SSY, and watershed area, A, is SSY = 300A-0.24 with an average error of 75%. Besides the specific sediment yield, the mean annual discharge, the normalized flow duration curve, the sediment rating curve, the normalized cumulative distribution curve, and the half yield discharge vary with watershed area. From the normalized flow duration curve at an exceedance probability of 0.1%, small watersheds (A<500 km2) have 42 <Q /¯Q < 63, compared to large watersheds (A > 5000 km2) which have 14 < Q/¯Q < 33. In terms of sediment rating curves, at a given discharge, the sediment load of small watersheds is one order of magnitude higher than for large watersheds. From the normalized cumulative distribution curves, the half yield (50% of the sediment transported) occurs when the discharge is at least 15 times the mean discharge. In comparison, the half yield for large watersheds corresponds to Q/¯Q <… Advisors/Committee Members: Julien, Pierre Y. (advisor), Ettema, Robert (committee member), Nelson, Peter (committee member), Rathburn, Sara L. (committee member).

Subjects/Keywords: mean annual sediment yield; sediment yield; flow duration curve; South Korea; modified Einstein procedure

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APA (6^th Edition):

Yang, C. (2019). Sediment yield of South Korean rivers, The. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/195392

Chicago Manual of Style (16^th Edition):

Yang, Chun-Yao. “Sediment yield of South Korean rivers, The.” 2019. Doctoral Dissertation, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/195392.

MLA Handbook (7^th Edition):

Yang, Chun-Yao. “Sediment yield of South Korean rivers, The.” 2019. Web. 12 Apr 2021.

Vancouver:

Yang C. Sediment yield of South Korean rivers, The. [Internet] [Doctoral dissertation]. Colorado State University; 2019. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/195392.

Council of Science Editors:

Yang C. Sediment yield of South Korean rivers, The. [Doctoral Dissertation]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/195392

9. Vandermause, Renee A. Role of dynamic ice-breakup on bank erosion and lateral migration of the Middle Susitna River, Alaska, The.

Degree: MS(M.S.), Civil and Environmental Engineering, 2018, Colorado State University

URL: http://hdl.handle.net/10217/191335

► Rivers in northern, boreal regions experience frigid winters and ice formation that influence several geomorphic processes including bank erosion and lateral channel migration. Not only… (more)

▼ Rivers in northern, boreal regions experience frigid winters and ice formation that influence several geomorphic processes including bank erosion and lateral channel migration. Not only are the ice-driven processes complex and highly variable in time and space, but they are difficult to observe due to the logistical challenges of conducting fieldwork when the rivers are frozen in the winter and during ice breakup in the spring. Yet, characterizing and quantifying the processes that drive bank erosion, whether during the summer open-water period or when ice is in the channel, is important for predicting channel dynamics in the boreal rivers where there is a mixed ice-fluvial regime. Of particular importance is understanding the erosional processes that form or maintain complex channel and riparian systems which in turn provide diverse aquatic habitat for a range of salmonid species. This study capitalized on an extensive archive of field data and observations, of which the author was involved, to quantify the extent to which channel change is driven by ice and fluvial processes on the Susitna River, a large gravel-cobble bed river in south-central Alaska. As bank erosion is a key element of channel change, this study focused on bank erosion along the middle reach of Susitna River located downstream of a proposed dam site. Using aerial photography and videography over two one-year periods, 2011 to 2012 (included a thermal ice-breakup) and 2012 to 2013 (included a dynamic ice-breakup), the study identified short-term erosion rates for distinct geomorphic reaches, determined the amount of erosion by the type of geomorphic surface, and quantified when the most bank erosion occurred annually; whether during the open-water season or when ice was in the channel, particularly during ice-breakup. The aerial imagery was supplemented by observations and data collected along the Middle Susitna River over two field seasons. The study also used a synthesis of observations and 2-D depth averaged fluvial modeling using SRH-2D to characterize processes that drive bank erosion. This study found that the majority of bank erosion, 54 to 61 percent by sub-reach, occurs or is initiated over a short period of time during dynamic breakup of the river's ice cover. The dominant erosion process is attributable to the combination of relatively high-water discharge and the presence of ice floes and ice rubble. Vegetated bars and terrace margins were the most susceptible to bank erosion, notably by impacting ice floes. Erosion of banks adjoining floodplain surfaces, partly protected by vegetation rootmats and by shear walls of smaller ice rubble, accounted for less overall erosion than vegetated bars or terraces. Wide sub-reaches with multiple channels were prone to ice-jamming, diversion of flow conveying ice into side channels, and localized pockets of subsequent bank erosion. Bank erosion occurred less in predominantly single-channel reaches than in the predominantly multi-channel reaches. Rates of bank erosion along the Middle Susitna River… Advisors/Committee Members: Ettema, Robert (advisor), Zevenbergen, Lyle (advisor), Rathburn, Sara (committee member).

Subjects/Keywords: boreal river; erosion; banks; ice; breakup

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APA (6^th Edition):

Vandermause, R. A. (2018). Role of dynamic ice-breakup on bank erosion and lateral migration of the Middle Susitna River, Alaska, The. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/191335

Chicago Manual of Style (16^th Edition):

Vandermause, Renee A. “Role of dynamic ice-breakup on bank erosion and lateral migration of the Middle Susitna River, Alaska, The.” 2018. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/191335.

MLA Handbook (7^th Edition):

Vandermause, Renee A. “Role of dynamic ice-breakup on bank erosion and lateral migration of the Middle Susitna River, Alaska, The.” 2018. Web. 12 Apr 2021.

Vancouver:

Vandermause RA. Role of dynamic ice-breakup on bank erosion and lateral migration of the Middle Susitna River, Alaska, The. [Internet] [Masters thesis]. Colorado State University; 2018. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/191335.

Council of Science Editors:

Vandermause RA. Role of dynamic ice-breakup on bank erosion and lateral migration of the Middle Susitna River, Alaska, The. [Masters Thesis]. Colorado State University; 2018. Available from: http://hdl.handle.net/10217/191335

10. Zey, Scott S. Flow field at open-channel contractions: insights from a two-dimensional numerical model.

Degree: MS(M.S.), Civil and Environmental Engineering, 2017, Colorado State University

URL: http://hdl.handle.net/10217/185693

► A depth averaged, two-dimensional numerical model was used to investigate the hydraulics of flow passing through open-channel contractions. The investigation focused on the magnitude and… (more)

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APA (6^th Edition):

Zey, S. S. (2017). Flow field at open-channel contractions: insights from a two-dimensional numerical model. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/185693

Chicago Manual of Style (16^th Edition):

Zey, Scott S. “Flow field at open-channel contractions: insights from a two-dimensional numerical model.” 2017. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/185693.

MLA Handbook (7^th Edition):

Zey, Scott S. “Flow field at open-channel contractions: insights from a two-dimensional numerical model.” 2017. Web. 12 Apr 2021.

Vancouver:

Zey SS. Flow field at open-channel contractions: insights from a two-dimensional numerical model. [Internet] [Masters thesis]. Colorado State University; 2017. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/185693.

Council of Science Editors:

Zey SS. Flow field at open-channel contractions: insights from a two-dimensional numerical model. [Masters Thesis]. Colorado State University; 2017. Available from: http://hdl.handle.net/10217/185693

11. Palu, Marcos Cristiano. Floodwave and sediment transport assessment along the Doce River after the Fundão Tailings Dam collapse (Brazil).

Degree: PhD, Civil and Environmental Engineering, 2019, Colorado State University

URL: http://hdl.handle.net/10217/195309

► The collapse of the Fundão Tailings Dam in November 2015 spilled 32 Mm3 of mine waste, causing a substantial socio-economic and environmental damage within the… (more)

▼ The collapse of the Fundão Tailings Dam in November 2015 spilled 32 Mm3 of mine waste, causing a substantial socio-economic and environmental damage within the Doce River basin in Brazil. Approximately 90% of the spilled volume deposited over 118 km downstream of Fundão Dam on floodplains. Nevertheless, high concentration of suspended sediment (≈ 400,000 mg/l) reached the Doce River, where the floodwave and sediment wave traveled at different velocities over 550 km to the Atlantic Ocean. The one-dimensional advection-dispersion equation with sediment settling was solved to determine, for tailing sediment, the longitudinal dispersion coefficient and the settling rate along the river and in the reservoirs (Baguari, Aimorés and Mascarenhas). The values found for the longitudinal dispersion coefficient ranged from 30 to 120 m2/s, which are consistent with those in the literature. Moreover, the sediment settling rate along the whole extension of the river corresponds to the deposition of finer material stored in Fundão Dam, which particle size ranged from 1.1 to 2 μm. The simulation of the flashy hydrographs on the Doce River after the dam collapse was initially carried out with several widespread one-dimensional flood routing methods, including the Modified Puls, Muskingum-Cunge, Preissmann, Crank Nicolson and QUICKEST. All of these methods presented unsatisfactory results, with prediction errors in peak discharge up to 44%, and differences in timing to peak up to 5 hours. A new and more accurate one-dimensional flood routing approach was then used, solving the full dynamic equation into an equivalent diffusive wave format and reformulating the hydraulic diffusion coefficient in terms of the Froude number and floodwave celerity. The numerical solution to this new approach was implemented using Crank Nicolson and QUICKEST schemes. The error in predicted peak discharge along the Doce River was reduced to 2%, and the maximum difference found in time to peak was about 1 hour. Regarding sediment transport, a comprehensive one-dimensional numerical model is developed, coupling the new floodwave propagation algorithm with the numerical solution for advective sediment transport and settling. One of the main features of this model is the ability to simulate the propagation of the floodwave and sediment through the entire Doce River extension with or without reservoirs. A sensitivity analysis showed that a hypothetical decrease in water temperature from 30°C to 5°C would have resulted in a concentration 13 times higher at the outlet. In addition, without the presence of hydropower reservoirs on the Doce River, the sediment concentration at the basin outlet would have been 70,000 mg/l instead of the observed 1,600 mg/l. Finally, a simplified numerical model based on the Doce River measurements can simulate the hypothetical collapse of 56 tailings dams in the Doce River basin to estimate the potential impact on the water supply for the towns along the river. Those simulation results show that tailings dams located in the Piracicaba… Advisors/Committee Members: Julien, Pierre (advisor), Thornton, Christopher (committee member), Ettema, Robert (committee member), Rathburn, Sara (committee member).

Subjects/Keywords: Doce River; Fundão Tailings Dam; transport of suspended sediment; floodwave propagation; dam break; one-dimensional advection-dispersion equation

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APA (6^th Edition):

Palu, M. C. (2019). Floodwave and sediment transport assessment along the Doce River after the Fundão Tailings Dam collapse (Brazil). (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/195309

Chicago Manual of Style (16^th Edition):

Palu, Marcos Cristiano. “Floodwave and sediment transport assessment along the Doce River after the Fundão Tailings Dam collapse (Brazil).” 2019. Doctoral Dissertation, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/195309.

MLA Handbook (7^th Edition):

Palu, Marcos Cristiano. “Floodwave and sediment transport assessment along the Doce River after the Fundão Tailings Dam collapse (Brazil).” 2019. Web. 12 Apr 2021.

Vancouver:

Palu MC. Floodwave and sediment transport assessment along the Doce River after the Fundão Tailings Dam collapse (Brazil). [Internet] [Doctoral dissertation]. Colorado State University; 2019. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/195309.

Council of Science Editors:

Palu MC. Floodwave and sediment transport assessment along the Doce River after the Fundão Tailings Dam collapse (Brazil). [Doctoral Dissertation]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/195309

12. Chen, Kaiwei. Application of large-scale particle image velocimetry at the Hydraulics Laboratory of Colorado State University.

Degree: MS(M.S.), Civil and Environmental Engineering, 2018, Colorado State University

URL: http://hdl.handle.net/10217/189265

► Large-scale particle image velocimetry (LSPIV) is a nonintrusive technique used to measure free-surface velocities of water flow in a manner that produces a two-dimensional vector… (more)

Subjects/Keywords: bendway weir; tracer size; LSPIV; accuracy

…is the first study at Colorado State University (CSU) to apply LSPIV for…

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APA (6^th Edition):

Chen, K. (2018). Application of large-scale particle image velocimetry at the Hydraulics Laboratory of Colorado State University. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/189265

Chicago Manual of Style (16^th Edition):

Chen, Kaiwei. “Application of large-scale particle image velocimetry at the Hydraulics Laboratory of Colorado State University.” 2018. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/189265.

MLA Handbook (7^th Edition):

Chen, Kaiwei. “Application of large-scale particle image velocimetry at the Hydraulics Laboratory of Colorado State University.” 2018. Web. 12 Apr 2021.

Vancouver:

Chen K. Application of large-scale particle image velocimetry at the Hydraulics Laboratory of Colorado State University. [Internet] [Masters thesis]. Colorado State University; 2018. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/189265.

Council of Science Editors:

Chen K. Application of large-scale particle image velocimetry at the Hydraulics Laboratory of Colorado State University. [Masters Thesis]. Colorado State University; 2018. Available from: http://hdl.handle.net/10217/189265

Colorado State University

13. Beikmann, Alise Marie. Water resources on outer-lying islands in Micronesia.

Degree: MS(M.S.), Civil and Environmental Engineering, 2016, Colorado State University

URL: http://hdl.handle.net/10217/173538

To view the abstract, please see the full text of the document. Advisors/Committee Members: Bailey, Ryan (advisor), Ettema, Robert (committee member), Grigg, Neil (committee member), Ronayne, Michael (committee member).

Subjects/Keywords: drought; atoll; rainwater; groundwater; Micronesia

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Beikmann, A. M. (2016). Water resources on outer-lying islands in Micronesia. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/173538

Chicago Manual of Style (16^th Edition):

Beikmann, Alise Marie. “Water resources on outer-lying islands in Micronesia.” 2016. Masters Thesis, Colorado State University. Accessed April 12, 2021. http://hdl.handle.net/10217/173538.

MLA Handbook (7^th Edition):

Beikmann, Alise Marie. “Water resources on outer-lying islands in Micronesia.” 2016. Web. 12 Apr 2021.

Vancouver:

Beikmann AM. Water resources on outer-lying islands in Micronesia. [Internet] [Masters thesis]. Colorado State University; 2016. [cited 2021 Apr 12]. Available from: http://hdl.handle.net/10217/173538.

Council of Science Editors:

Beikmann AM. Water resources on outer-lying islands in Micronesia. [Masters Thesis]. Colorado State University; 2016. Available from: http://hdl.handle.net/10217/173538

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