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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

Hydraulic characteristics of circular culvert inlets relating to fish passage

Hunt, Martin 24 September 2012 (has links)
This thesis presents the findings of a physical modeling study examining the hydraulic characteristics within the inlet region of a corrugated steel pipe (CSP) culvert with common inlet treatments. Also examined are the effects of embedding the culvert below the stream bed and backfilling the culvert with granular material. Velocity and turbulence distributions were examined in an effort to better understand how these inlet treatments may affect fish passage. The velocity field of each inlet configuration was dominated by a central jet of high velocity surrounded by low velocity boundary areas. Based on percent area analysis the various projecting end inlet configura-tions presented the largest area with streamwise velocities less than Uavg. The usefulness of the low velocity boundary areas may be limited by significant vertical and spanwise velocities and associated elevated turbulence levels.
2

Hydraulic characteristics of circular culvert inlets relating to fish passage

Hunt, Martin 24 September 2012 (has links)
This thesis presents the findings of a physical modeling study examining the hydraulic characteristics within the inlet region of a corrugated steel pipe (CSP) culvert with common inlet treatments. Also examined are the effects of embedding the culvert below the stream bed and backfilling the culvert with granular material. Velocity and turbulence distributions were examined in an effort to better understand how these inlet treatments may affect fish passage. The velocity field of each inlet configuration was dominated by a central jet of high velocity surrounded by low velocity boundary areas. Based on percent area analysis the various projecting end inlet configura-tions presented the largest area with streamwise velocities less than Uavg. The usefulness of the low velocity boundary areas may be limited by significant vertical and spanwise velocities and associated elevated turbulence levels.
3

Fish Passage at UDOT Culverts: Prioritization and Assessment

Beavers, Aaron Evens 29 July 2008 (has links) (PDF)
State Departments of Transportation are becoming more involved in providing Aquatic Organism Passage (AOP) at road-stream crossings. Department of Transportation (DOT) emphasis on AOP has been driven largely in response to endangered species listings, other agencies' initiatives, and the desire to restore ecosystem connectivity to watercourses. UDOT is currently responsible for approximately 47,000 culverts, but AOP is currently addressed only on an as-needed basis. Currently UDOT has no prioritization or assessment strategy procedure for AOP at UDOT road-stream crossings. Historical fish passage strategies have focused on federally listed adult anadromous salmon and trout. These are generally very large fish whose life cycle includes both fresh and salt water environs. These species have adapted to the wetter conditions prevalent in their Pacific Northwest habitat. However, Utah fish species have adapted to the arid conditions of the Great Basin, are generally much smaller, and complete their life cycle entirely within fresh water. For UDOT these differences represent a potential fundamental divergence in the approaches used for providing fish passage in Utah vs. those historically used in the Pacific Northwest. The purpose of this research was to develop a method of prioritizing culverts statewide and to modify existing culvert assessment procedures for UDOT within a Great Basin/Utah regional context. Developed as part of the research are tools to prioritize and assess culverts. A GIS database was developed to store fish passage assessment data as well as provide functions for prioritizing culverts on the state and regional level. A fish passage assessment protocol for assessing UDOT culverts was developed based on existing fish passage assessments. The culvert assessment was tailored to meet developed UDOT fish passage strategies. A training manual was also created to aid technicians on performing the several physical culvert assessments developed. Additionally, a mark and recapture study at six UDOT culverts was performed to field verify the developed culvert assessment procedure. A step by step methodology was then created to establish critical progression for prioritizing and assessing culverts for fish passage utilizing project results.
4

Atlantic salmon in regulated rivers : Migration, dam passage, and fish behavior

Nyqvist, Daniel January 2016 (has links)
Hydropower dams block migration routes and disrupt longitudinal connectivity in rivers, thereby posing a threat to migratory fish species. Various fish passage solutions have been implemented to improve connectivity with varying success. A well-functioning passage solution must ensure safe and timely passage routes that are used by a substantial portion of the migrating fish. In this thesis, I report the results from telemetry studies where the behavior and survival of migrating Atlantic salmon spawners, post-spawners and smolts have been evaluated in relation to hydropower dam passage. I evaluate downstream passage performance at dams with no passage solutions in the River Klarälven, and with simple passage solutions in in the Winooski River. In the River Ätran, I study both upstream- and downstream passage performance at a dam with sophisticated passage solutions based on the best available technology. In addition, I have studied the survival and behavior of post-spawners and hatchery-released smolts. A substantial portion of the spawners survived spawning and initiated downstream migration. Most males migrated downstream in autumn following spawning, whereas females tended to stay in the river until spring. For hatchery-reared smolts, early release was associated with faster initiation of migration and higher survival compared to late release. Multiple dam passage resulted in high mortality for both smolts and kelts. For smolts, dam passage, even with simple passage solutions, was associated with substantial delay and mortality. High spill levels were linked to high survival and short delay for downstream migrating salmon. The best available passage solution, which consisted of a nature-like fishway and a low sloping intake rack to guide fish to a bypass, resulted in rapid passage of a large portion of the adult migrants.
5

Modeling the hydraulic characteristics of fully developed flow in corrugated steel pipe culverts

Toews, Jonathan Scott 25 September 2012 (has links)
The process of fish migration within rivers and streams is important, especially during the spawning season which often coincides with peak spring discharges in Manitoba. Current environmental regulations for fish passage through culverts require that the average velocity be limited to the prolonged swimming speed of the fish species present. In order to examine the validity of this approach, physical model results were used to calibrate and test a commercially available Computational Fluid Dynamics (CFD) model. Detailed analysis showed that CFD models and the empirical equations used were both able to give a better representation of the flow field than the average velocity. However, the empirical equations were able to provide a more accurate velocity distribution within the fully developed region. A relationship was then developed, to estimate the cumulative percent area less than a threshold velocity within CSP culverts, to be used as a guideline during the design phase.
6

Modeling the hydraulic characteristics of fully developed flow in corrugated steel pipe culverts

Toews, Jonathan Scott 25 September 2012 (has links)
The process of fish migration within rivers and streams is important, especially during the spawning season which often coincides with peak spring discharges in Manitoba. Current environmental regulations for fish passage through culverts require that the average velocity be limited to the prolonged swimming speed of the fish species present. In order to examine the validity of this approach, physical model results were used to calibrate and test a commercially available Computational Fluid Dynamics (CFD) model. Detailed analysis showed that CFD models and the empirical equations used were both able to give a better representation of the flow field than the average velocity. However, the empirical equations were able to provide a more accurate velocity distribution within the fully developed region. A relationship was then developed, to estimate the cumulative percent area less than a threshold velocity within CSP culverts, to be used as a guideline during the design phase.
7

Fish Passage Through Rehabilitated Culverts Laboratory Study

Olsen, Amber H. 01 December 2011 (has links)
Culverts are rehabilitated using a variety of techniques; the approach studied in this report focuses on the use of slip liners. Slip lining refers to installing a liner pipe inside a host pipe to extend its useful life. Slip lining reduces the diameter of the culvert; however, when a smooth-walled liner [e.g., high-density polyethylene (HDPE)] is installed in a profiled-wall pipe (e.g., corrugated metal pipe), the reduction in hydraulic roughness helps to compensate for the reduction in flow area, minimizing any reduction in discharge capacity. In some cases, the discharge capacity may increase. A smaller diameter liner, made of smoother material, will likely produce larger pipe flow velocities relative to the host culvert. High velocities can potentially create a barrier for fish passage, discouraging their use in areas sensitive to fish passage. The objective of this research was to find ways to implement slip liners and still accommodate fish passage. A 60-ft long, 2-ft diameter, baffled slip liner was tested at seven slopes (0-3.5%) and at three flow rates per slope (1-4.6 cfs). For comparison purposes, tests were also conducted on a smooth-walled (non-baffled) liner. Baffles were found to greatly increase the potential for low-flow fish passage, allowing passage up to slopes of 3.5%. Conversely, the smooth-walled liner prohibited passage beyond a 1.0% slope. The potential drawback to using baffles in a slip-lined culvert is the reduction in culvert flow capacity. Compared to the smooth-walled liner, the baffled culvert reduced the flow capacity of the culvert by about 74% at pressurized, full pipe flow. Finally, velocity was measured with an acoustic Doppler velocimeter (ADV) in the baffled culvert and turbulence values were calculated using four different methods. The Energy Dissipation Factor, or EDF, values had a close relationship with percent fish passing and if more testing is done, it could be used as a scaling factor to transfer fish passage data to other sized culverts. The results of this study, suggest that baffled slip-lined culverts can aid fish passage and are useful for culvert rehabilitation as long as the culvert can still maintain appropriate flow capacity.
8

Computational Study of Fish Passage through Circular Culverts in Northeast Ohio

Baral, Darshan 29 May 2013 (has links)
No description available.
9

Culvert Roughness Elements for Native Utah Fish Passage: Phase I

Esplin, Lindsay D. 16 March 2011 (has links) (PDF)
Culverts can increase stream velocities as a result of reduced waterway areas and prevent upstream passage of small non-salmonid fish such as the Native Utah Leatherside chub (Gila copei) and Longnose dace (Rhinichthyscataractae). To mitigate this problem, current culvert design standards for fish passage match sustained fish swim speeds with average cross sectional velocity through the culvert. Such policies dictate relatively large barrels and do not recognize the role of reduced velocity zones near culvert boundaries. Obstacles and streambed substrate create turbulent regions with lower velocity zones that can increase upstream fish passage. A comparison of upstream passage success using native Utah fish in an experimental flume was conducted with three different conditions: (1) a smooth boundary, (2) a smooth boundary with strategically placed cylinders, and (3) a boundary consisting of natural substrate. The refuge provided by the cylinders and substrate allowed fish to expend less energy as they swam upstream. Energy expenditure was compared between the conditions by mapping the velocity field near the boundary and tracing fish swim paths. Substrate provided sufficient refuge for the fish to behave in a manner similar to their behavior in a natural environment and with significantly reduced energy expenditure. Cylinders provided limited refuge that allowed fish to rest periodically as they navigated the flume. The smooth boundary case required the highest energy expenditure as there was no refuge provided. Fish swimming capabilities in the form of prolonged and burst velocities have been recorded for most species. Streamwise velocity near the boundary can be compared to the prolonged and burst swim speeds to predict passage rates. Further field testing is necessary to fully substantiate the effectiveness of utilizing reduced velocity zones in non-salmonid fish passage prediction. If such a design approach can be used instead of using the conservative but overly simplistic average velocity to evaluate the retrofit of existing culverts and to design new culverts it will help minimize costs and result in fewer culvert replacements and smaller and simpler new designs. Other implications such as downstream effects on stream bed stability and scour remain an issue.
10

Culvert Roughness Elements for Native Utah Fish Passage: Phase II

Monk, Suzanne Kim 09 July 2012 (has links) (PDF)
Native fishes have become an increasingly important concern when designing fish passable culverts. Many operational culverts constrict waterways which increase velocities and prevent upstream passage of small fish species. The current method to ensure fish passage is to match the average cross sectional velocity to the sustained swim speed of the fish. This study investigates the passage rates of leatherside chub (Lepidomeda aliciae) and speckled dace (Rhinichthys osculus) at three sites (an arch culvert with substrate bottom, box culvert with bare bottom, and a stream section with no culvert) located on Salina Creek near Salina, UT. It was found that fish were able to pass through all of the sites. However, fish were able to take advantage of the habitat within the culvert that had a substrate bottom more effectively than within the culvert that had no substrate within the barrel. This was reflected in population density estimates at each of the three test sites for each species. It was also found that the substrate at the arch culvert and stream sites scaled with the fish measured in this study. The D50 and D84 were 44 and 205 mm at the arch culvert site and 26 and 126 mm at the stream site. The average fish length was 76 mm for the chub and 64 mm for the dace. It is recommended that (1) a culvert size that produces a velocity equal to the prolonged swim speed of target fish in the near boundary region (2 cm above the bed) be used in the future, and (2) substrate that scales with the target fish species be placed in the culvert barrel.

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