Green and Birkenhead Rivers are located in the southwestern Coast Mountains of British Columbia, and the drainage in both basins is still strongly controlled by glacial features left after the retreat of the Vashon ice sheet. River slopes are imposed on the upland streams while the slope of the main valley streams is at least partly imposed by the glacial topography. Discharge in the streams is dominated by snowmelt during the summer though peak daily discharges frequently occur in autumn during autumn storms. At-a-station hydraulic geometry curves were determined by least square regression analysis for five sections from Water Survey of Canada gauging records. Velocity shows a more rapid than usual rate of adjustment, and resistance decreases more rapidly than the average as discharge increases. Residual values appear to be distributed about the regression lines in a systematic manner suggesting that the channel form fluctuates systematically over time. Similar results were found for ten other sections in the southwestern Coast Mountains. Downstream hydraulic geometries were determined for Green River and Birkenhead River. Bankfull discharge was assumed to have a constant recurrence interval of 2.33 years for both basins. Channel width shows a greater than usual increase in the downstream direction while velocity appears to remain constant or decrease. / Arts, Faculty of / Geography, Department of / Graduate

Temporal and spatial variations of the Fraser River plume, in the central Strait of Georgia (British Columbia, Canada), are monitored by continuous salinity sampling of the engine cooling water on two B.C. ferries. Travelling along two different routes between Vancouver Island and the mainland the ferries provide eight crossings per day both north and south of the river outflow. From each crossing, characteristic measures of the plume are extracted, such as the average salinity and the maximum salinity gradient. These parameters are then formulated as time series and used to compute cross-correlations and cross-spectra with the probable driving forces of wind and river discharge. The effect of the tides is examined using harmonic analysis. Periods of high river discharge lead to decreases in the average salinity for each section, and peaks in the magnitude of the maximum salinity gradient. The correlation of the plume characteristics (average salinity, maximum salinity gradient) on the southern section with the along-strait component of the wind is consistent with advection by the wind. Weak correlation is found between the plume characteristics on the northern section and the wind. Linear combination of the wind and the discharge variations reproduce the general trend of the average salinities but cannot explain the level of variability. A shift to a nonlinear combination of the wind and discharge improves this comparison. The phases of parameter fluctuations at tidal frequencies, on the southern section, agree with the expected effects of tidal currents and the modulation of the river discharge. The agreement is not as apparent for the northern section. The level of the discharge is seen to affect the tidal amplitudes of the salinity fluctuations on the southern section. A numerical model, previously developed to examine the effect of tidal forcing on the plume, is modified to input the hourly wind and daily discharge data record. Equivalent average salinities along the ferry section are outputed and compared to the observed ferry data. Good agreement is reached after manipulating the entrainment velocity and the momentum transfer from the wind to the plume. The tides are seen to add a tidal modulation to the general salinity pattern resulting from the combined effect of the wind and the discharge. Horizontal distributions from the model and from CTD cruise results agree fairly well with each another. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Ice regime plays a significant role in River hydraulics and morphology in Northern hemisphere countries such as Canada. The formation, propagation and recession of ice cover introduce a dynamic boundary layer to the top of the stream. Ice cover affects the water velocity magnitude and distribution, water level and consequently conveyance capacity. A stable ice cover also tends to reduce bed shear and associated sediment transport, but bank scour and ice jamming events can increase sediment entrainment. These effects are even more intense during the ice cover break-up period when extreme conditions such as ice-jamming and release and mechanical ice cover break-up can locally accelerate the flow, and ice can mechanically scour the river bed and banks. The presence of ice has some important implications for hydro-electrical power generation operations too. The ice cover changes the channel conveyance capacity (and therefore increases the flood risk), may increase sediment transport and causes scouring, and is likely to block water intakes and turbines. The rate of water release should, therefore, be adjusted in the presence of the ice cover to avoid unwanted consequences on the dam structure and equipments as well as on the downstream channel and the environment. Even though the influence of ice cover on rivers is widely recognized, large gaps still exist in our understanding of ice cover processes in rivers. Two main reasons for such a shortage are the difficulty and danger involved in collecting hydraulic and sediment transport data under ice cover, especially during the unstable periods of freeze-up and break-up. In the absence of sufficient data, the applicability of available formulae and theories on hydraulic processes in ice-covered rivers cannot be extensively tested and improved. The purpose of this research mainly is a) to perform a continuous, in-situ monitoring of water velocity profiles, sediment loads and ice-cover condition during several years through winter field campaigns at a section of the Lower Nelson River, Manitoba, Canada.The Lower Nelson River is a regulated river (Manitoba Hydro). It receives augmented flow from the Churchill River Diversion, and is subject to operation of many hydro-electricity facilities, one of which is currently under construction, while others are planned to be constructed in the future. Due to the geographical location of the study reach, it is covered by ice and experiences severe ice condition for several months during the year. b) Analysis of the collected data in order to study the impact of ice cover on the hydraulic properties and sediment conveyance capacity at the study reach and c) using the insight gained from the field data analysis to improve a river ice simulation model to apply in the study of Lower Nelson River ice regime. The selection of the Lower Nelson river is motivated by intention of Manitoba Hydro (MH) ,as the industrial partner in this research, to study the winter flow regime at the Lower Nelson River. Manitoba Hydro operates several dams on the Lower Nelson River and is considering more hydropower developments in the future. This study is composed of six steps as are described in the following main steps. Step 1: Selection of potential study sites and data collection techniques: The particular study site for this research is located immediately upstream of Jackfish Island, between Limestone generating station and Gillam Island in Lower Nelson River, Manitoba, Canada. River width at the study site location is about 1km. Water depth at the deployment site varies between 10-12 meters depending on both the time of year and the time of day due to hydropeaking fluctuations. Given the low accessibility to the field during winter time and considering the type of the required data, acoustic techniques were selected as the main approach for the field measurements. Two types of acoustic instruments, Acoustic Doppler Current Profiler (ADCP) and Shallow Water Ice Profiling Sonar (SWIPS) are selected for field investigations in this study. Both of them were planned to be deployed in the river for an extended period of time in order to record necessary data during the ice cover and open water periods. Step 2: Data acquisition. After the site selection and defining the appropriate techniques, data acquisition has been started through a series of annual field measurement campaigns starting from winter 2012. Measured data mainly consist of water velocity and sediment suspension during various ice cover stages, including river ice break-up. The velocity profiles are analyzed to determine dynamic changes in boundary shear stress and hydraulic resistance and stresses in the flow during the both open water and ice cover periods. Step 3: Data analysis and development/testing of roughness and sediment transport formulas. Several aspects of river-ice interactions are covered in the recorded data including ice cover condition and cover thickness variation, river hydraulic characteristics such as depth and velocity and finally information about the concentration of suspended particles. These data are analyzed to define the behavior of the ice cover and river during different ice stages. Ice effect on river conveyance capacity is also evaluated . The accuracy of common assumptions in composite roughness calculations in rivers is estimated and a new approach is developed and validated using the field observations and measurements. Ice cover influence on suspended sediment concentration is also studied as the other part of this research. Considering the type of the river sediment load (mostly bed load) available methods for sediment transport simulation are studied and applied for estimation of the sediment transport under ice cover condition. According to the results, the most suitable methods were planned to be a part of the river ice numerical simulation model, developed in this study. Turbulent characteristics in ice covered flows are also studied through two years of data recordings. Acoustic Doppler Current Profiler employed in this study is programmed for appropriate recording of the water velocity for this purpose. Results are analyzed and turbulent structures in the river are studied in this research as well. Step 4: Testing of Hatch-MH’s river ice simulation model. A numerical model has been selected in order to simulate the river ice process at the study site (LNR). ICESIM, a steady state, one-dimensional river ice process model originally developed in 1973 by Acres International Limited (now Hatch), is selected for this study.ICESIM is originally developed in FORTRAN and is capable of predicting the progression and stabilization of river ice cover. Step 5: Improvement of Hatch-MH’s river ice simulation model: ICESIM model is converted to Matlab as the first step of the model improvements. A Graphical User Interface (GUI) is designed for the program which facilitates the assessment of model performance during the simulation leads to a more user-friendly model to operate. The new model, ICESIMAT is calibrated and evaluated based on the conducted field studies. Simulation capabilities of ICESIMAT are improved in the form of extended or additional subroutines to enhance its capabilities in the simulation of river ice processes and sediment transport. The current version of ICESIMAT is a steady state model, capable of simulating river ice , river hydrodynamic characteristics and sediment transport along the study reach. Though the model is restricted in the terms of the dimensions of the simulation (only one dimensional) its lower computational cost, permits a longer study reach to be simulated (in the scale of hundred kilometers instead of couple hundred meters in three dimensional simulation). ICESIM model is unable to simulate the break-up period which reduces the model capability in the simulation of the complete cycle of river ice. New subroutines are designed and added to extend the model capability to include simulation of ice processes during the ice cover break-up and finally to calculate the sediment transport under the ice cover. Step 6: As the final step, the new subroutines are adjusted and linked to the main improved code, providing a new framework for dynamic ice cover simulation, more prepared for further future improvements both in terms of conceptual and programming aspects of the river ice modeling . The new Matlab basis of the code facilitates upgrading the model to include more complicated processes like river ice jam simulations. As the general result of this thesis, we have a better understanding of hydraulics and sediment transport processes in ice covered rivers ( direct and indirect measurements of river hydraulics characteristics), improved formulas for these processes (including more involving parameters) and a better version of the river ice simulation model (capable of simulating the complete river ice processes) for the contributors to this study in the industry.

The structure of the western three or four miles of the Bear River range east of Logan, Utah, has many times been alluded to in papers written locally on Cache Valley and the related ranges. There has not however, ever been, to the author's knowledge, an investigation made of this portion of the range for the express purpose of determining its exact structure. Although the area specifically covered by this present investigation is greatly inadequate to base the whole west range structure on, the author believes that the facts brought to light by the specific study of this area, added to the facts already known of the rest of the range, will give a clearer and more comprehensive interpretation of the whole western Bear River range front. It was with this purpose in mind that the present investigation was made. The original outline for the study included an investigation of the paleontology of the section. It was found however, after a few weeks study in the field, that the fossils in the local section are far too scarce for any comprehensive study in the present investigation. The study herein described then will be found to refer to paleontology only where it is necessary or where fossil horizons were found advantageous over lithologic units for mapping of formations. The section represented here has several times been studied in part. With a study of these investigations, it was found that there was enough lithologic difference in most of the sections to make possible local correlation and mapping on that basis. In order to make the present paper more thorough and complete it seemed advisable to branch out from the specific area in a few cases and investigate other parts of the valley and range for further insight.into some of the problems confronted on the area. It was also found necessary to make a rather complete study of the literature of related areas.

Suspended-load rivers are subject to rapid geomorphic changes. In particular during the Holocene Epoch, arroyos of the Colorado Plateau experienced several periods of rapid erosion and aggradation. The most recent period of entrenchment occurred around the turn of the 20th century. The mechanisms responsible for the modern period of aggradation that has followed the most recent period of entrenchment have not been well documented. The research presented in this thesis reveals the mechanisms responsible for modern alluviation of the San Rafael River, which drains the Colorado Plateau The lower 87 km of the San Rafael River, which enters the Green River south of the town of Green River, UT has experienced rapid geomorphic changes during the last 100 years. To quantify these changes, we used a complement of temporally precise and spatially robust methods. By understanding the rates, magnitudes and types of geomorphic changes, we could then identify the mechanisms of these channel changes. The San Rafael River narrowed by 83% between 1938 and 2009 and the floodplain aggraded 1.0 to 2.5 m. Channel narrowing was caused by a reduction in the transport capacity of the river, and was accelerated by the establishment of vegetation, including the non-native tamarisk shrub, on active channel surfaces and the floodplain. Significant water withdrawals during the 20th century have primarily been responsible for the reduction in transport capacity by decreasing the magnitude and duration of the annual snowmelt flood. During this time period, monsoon floods continued to deliver large quantities of fine sediment to the channel. During the 20th century, the channel bed incised in one segment and aggraded in five segments. The two periods of incision that we documented were related to human modifications of the channel and floodplain. With the knowledge of the physical processes that have been responsible for the channel changes in the San Rafael River, prediction of future channel conditions can then be made. The changes to the physical template of the San Rafael River have implications for the management of three endemic fish – the roundtail chub (Gila robusta robusta), the bluehead sucker (Catostomus discobolus), and the flannelmouth sucker (Catostomus latipinnis) – which currently utilize the study area.

This thesis examined the relationships among ecology, economy, and society in the history of Longview, Washington, a planned timber settlement on the Columbia and Cowlitz Rivers. It compared the environmental, economic, and social histories of the Cowlitz Indians, American farmers, and urban industrialists that lived there over the past four hundred years. The central argument of the thesis is that human society cannot separate its economic and social organization from its ecology, nor can it reorder the environment without restructuring its economic and social institutions. Three different groups lived in the same physical space, but since they conceived and used the land differently, their societies developed distinct social and economic frameworks. The narrative of the thesis is chronological, tracing environmental, economic, and social change from about 1790 to 1934. During that time, humans gradually transformed a flood plain once dominated by vegetation and wildlife into a paved, sculpted, and densely populated industrial city. This study outlines the major causes and consequences of that transformation for both the land and its inhabitants. A wide range of source material provided the evidence upon which my conclusions were based. In addition to the more conventional historical sources such as diaries, letters, newspapers, memoirs, maps, and census data, I consulted anthropological studies, geological and geographical surveys, ecological reports, agricultural bulletins, and sociological analyses. My findings are presented in Chapters 2 through 5, with chapter 6 summarizing and drawing final conclusions.

The Mobile Basin is a prime example of a system that has undergone extensive channel modification with corresponding declines in the distribution and abundance of the native aquatic fauna. However, many of the declining aquatic species of the Mobile basin may persist within unmodified subbasins. The Noxubee River is a subbasin of the Mobile basin that has had very little alteration throughout its watershed. I investigated the species richness and assemblage structure to determine if the contemporary fish assemblage attributes resembled the conditions represented by historic collections. The findings of this study are important because the Noxubee River has not been extensively investigated since 1983, and the river could serve as refugia for declining riverine species of the Mobile basin. After examination at both local and regional levels, I determined that a diverse contemporary fish assemblage comprising 87 species, similar to historic collections, still persists in the Noxubee River system.

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No description available.

Rivers are considered as one of the most important surface water resources on the earth. During the time, most of the rivers on the earth experienced evolution and changes. River bends and confluences are one of the common cases in most rivers. There is a significant impact of the flow on the cross-sectional profile of river bends and confluences. Secondary currents are one of the important features that characterize flow in river bends and confluences. In such currents, fluid particles follow a helical path instead of moving nearly parallel to the axis of the channel. The local imbalance between the vertically varying centrifugal force and the cross-stream pressure gradient results in generating the secondary flow and raising a typical motion of the helical flow. Several studies, including experimental or mathematical, have been conducted to examine flow characteristics in curved open channels, river meanders, or confluences. In this research, the influence of secondary currents is studied on the elevation of water surface and the hydraulic structures in channel bends and confluences by employing a 3D OpenFOAM numerical model. The research implements a 3D OpenFOAM numerical model to simulate the horizontal distribution of the flow. In addition, the progress in unraveling and understanding the bend and confluent dynamics is discussed. The finite volume method in OpenFOAM software is used to simulate and examine the behavior of the secondary current. Thereafter, a comparison between the experimental data and a numerical model is conducted. Two sets of experimental data are used as the dataset for these two experiments are complete and validated; the data provided by Rozovskii (1961) for a sharply curved channel, and the dataset provided by Shumate (1998) for a confluent channel. Two solvers in OpenFOAM software were selected to solve the problem regarding the experiment: InterFoam and PisoFoam. InterFoam is a transient solver for incompressible flow that is used with open channel flow with Free Surface Model. PisoFoam is a transient solver for incompressible flow that is used with closed channel flow and Rigid-Lid Model. Various turbulence models (i.e., Standard k-ε, Realizable k-ε) are applied in the numerical model to assess the accuracy of turbulence models in predicting the behavior of the flow. The accuracies of various turbulence models are examined and discussed.