Bridge scour is the leading cause of bridge damage nationwide. Successfully mitigating bridge scour problems depends on our ability to reliably estimate scour potential, design safe and economical foundation elements that account for scour potential, identify vulnerabilities related to extreme events, and recognize changes to the environmental setting that increase risk at existing bridges. This study leverages available information, gathered from several statewide resources, and adds watershed metrics to create a comprehensive, georeferenced dataset to identify parameters that correlate to bridges damaged in an extreme flood event. Understanding the underlying relationships between existing bridge condition, fluvial stresses, and geomorphological changes is key to identifying vulnerabilities in both existing and future bridge infrastructure. In creating this comprehensive database of bridge inspection records and associated damage characterization, features were identified that correlate to and discriminate between levels of bridge damage. Stream geomorphic assessment features were spatially joined to every bridge, marking the first time that geomorphic assessments have been broadly used for estimating bridge vulnerability. Stream power assessments and watershed delineations for every bridge and stream reach were generated to supplement the comprehensive database. Individual features were tested for their significance to discriminate bridge damage, and then used to create empirical fragility curves and probabilistic predictions maps to aid in future bridge vulnerability detection. Damage to over 300 Vermont bridges from a single extreme flood event, the August 28, 2011 Tropical Storm Irene, was used as the basis for this study. Damage to historic bridges was also summarized and tabulated. In some areas of Vermont, the storm rainfall recurrence interval exceeded 500 years, causing widespread flooding and damaging over 300 bridges. With a dataset of over 330 features for more than 2,000 observations to bridges that were damaged as well as not damaged in the storm, an advanced evolutionary algorithm performed multivariate feature selection to overcome the shortfalls of traditional logistic regression analysis. The analysis identified distinct combinations of variables that correlate to the observed bridge damage under extreme food events.

The Bear River Range, in north-central Utah, contains a variety of geomorphic elements influenced by the geologic setting and events. Controlling factors of the geologic setting include: (1) a syncline (west) and an anticline with a crestal graben (east) within the part of the mountain range studied, and an adjacent graben valley along the west side of the range; and (2) bedrock of Precambrian and Paleozoic age in the core of the range, predominantly of shallow-marine carbonates and covered in the graben by shaly and conglomeratic rocks of early Cenozoic age, with fanglomerates and lake deposits of later Cenozoic age. Geologic events contributing to geomorphic development include: (1) (?) Bull Lake and Pinedale glaciation; ( 2) various levels of Lake Bonneville; and (3) Hypsithermal climatic conditions. The eighteen canyons along the western front of the Bear River Range in Utah, in sequence from north to south, are: High Creek, Oxkiller Hollow, Cherry Creek, City Creek, Nebo Creek, Smithfield, Birch, Dry (North), Hyde Park, Green, Logan, Dry (South), Providence, Millville, Blacksmith Fork, Hyrum, Paradise Dry, and East. An attempt was made to relate gradient changes along longitudinal canyon profiles to lithologies, attitudes, or other structural controls. The only consistent gradient change is a steepening of the gradient downstream from outcrops of Swan Peak Formation. A pronounced asymmetry in cross-valley profiles probably results from micro-climatic differences that cause north-facing slopes to be steeper than southfacing slopes despite close similarities in structure and lithology across canyons. Several canyons which do not cross the syncline axis have no measurable discharge. Water from these drainages apparently moves along the strike or down the east-dipping rocks of the western limb of the Logan Peak syncline to emerge as springs added to the surface flow in cross-axial canyon streams. Leakage is probably concentrated in the Lodgepole and Great Blue Formations. Minor geomorphic elements within the Bear River Range result from glacial, periglacial, and fluvial processes, and landslides. Periglacial action has produced both nivation and patterned diamicton. Glacial features are present in Logan Canyon and its tributaries, Birch, Providence, and the South Fork of Smithfield canyons. In addition to these previously mapped glacial areas, High Creek Canyon was subjected to glacial modification in the upper reach of South Fork tributary, and Leatham Hollow (Blacksmith Fork Canyon ), in the upper reach of its major southern tributary. Nivation modified the heads of Smithfield, Green, Cottonwood, and Dry (South) canyons by carving cirques floored by rock debris. Evidence for glacial action downstream from these cirques is absent. Patterned diamicton sites are widely distributed within the range. There is no consistent relationship to exposed lithologies or physical setting. The apparent relationship of slope aspect, elevation, and solar radiation suggests an origin by a temperature-dependent process, for near-identical temperatures were calculated for all patterned diamicton sites. Based, in part, on a reconstruction of Pleistocene temperatures, the patterned diamicton sites probably are a form of patterned ground resulting from frost action during glacial episodes. Alluvial fans lie at the mouths of many tributary canyons. Based on degree of soil development and relations to features of known age, a sequence of fan development is recognized. Alluvial fans formed prior to Wisconsinan time and repeatedly thereafter during interglacial and glacial periods. Many of the fans formed after the Pleistocene under the favorable conditions that existed during the Hypsithermal interval. Landslides in the study area are commonly old, inactive features. Only a few sites are recent in age, or currently active. Slopes with a west-component aspect are more prone to movement than other aspects. The most frequently disturbed lithology consists of Tertiary formations which are often conglomeratic. A wide range of slope inclinations have landslides, but the dominant slope is 20 to 24 percent. The main elevation range for landslides is between 6, 000 to 6, 999 feet. Quaternary stream alluvium and Lake Bonneville deposits are found along the eastern margin of Cache Valley and in the lower reaches of most canyons. This material has been deposited since the Provo phase of Lake Bonneville. In several places, lake or stream terraces are mapped.

This thesis was completed in order to assess and document the environmental effects that are the result of elemental phosphorus production in Pinellas County Florida. The study utilized a collection of information resources that included: personal interviews, technical references, historical documents, legal documents and field observations. By utilizing five different sources of information a broad understanding of the problem was developed. Pinellas County and Tarpon Springs officials were interested in creating a more diversified economy in the years following World War-II. The Victor Chemical Works Company responded to the interest in economic diversity by proposing to build an elemental phosphorus production facility in the area of greater Tarpon Springs, Florida. The elemental phosphorus production facility was completed and began operation in November of 1947. Three months after the facility commenced production local residents noticed damage to trees and painted surfaces on private properties. Seven months following commencement of elemental phosphorus production local residents filed suit against the Victor Chemical Works Company due to deleterious gasses and dust that appeared to be damaging to biologic health. The elemental phosphorus production facility operated from 1947 to 1981. The 34-year operational period exposed workers, residents and biologic communities to extended periods of elevated sulfur dioxide, phosphorus pentoxide gas, phosphine gas, fluorine, lead, radium-226 and asbestos. Utilizing personal interviews, technical document review, legal document review and field observations the thesis provided an amalgamation of diverse information upon which the conclusions were based. The research concludes that the production of elemental phosphorus exposed all physical and cultural environments of northwest Pinellas County to many complex adverse environmental impacts that continue to persist in 2007, approximately 26-years following the suspension of production.

Debris-flows pose serious hazards to communities in mountainous regions of the world and are often responsible for loss of life and damages to infrastructure. Characterised by high flow velocity, large impact forces and long runout, debris-flows have potential discharges several times greater than clear water flood discharges and possess much greater erosive and destructive potential. In combination with poor temporal predictability, they present a significant hazard to settlements, transport routes and other infrastructure located at the drainage points (fan-heads) of watersheds. Thus, it is important that areas vulnerable to debris-flows are identified in order to aid decisions on appropriate land-uses for alluvial fans. This research has developed and tested a new GIS-based procedure for identifying areas prone to debris-flow hazards in the Coromandel/Kaimai region, North Island, New Zealand. The procedure was developed using ESRI Arc View software, utilising the NZ 25 x 25 m DEM as the primary input. When run, it enabled watersheds and their associated morphometric parameters to be derived for selected streams in the study area. Two specific parameters, Melton ratio (R) and watershed length were then correlated against field evidence for debris-flows, debris-floods and fluvial processes at stream watershed locations in the study area. Overall, strong relationships were observed to exist between the evidence observed for these phenomena and the parameters, thus confirming the utility of the GIS procedure for the preliminary identification of hydrogeomorphic hazards such as debris-flow in the Coromandel/Kaimai region study area. In consideration of the results, the procedure could prove a useful tool for regional councils and CDEM groups in regional debris-flow hazard assessment for the identification of existing developments at risk of debris-flow disaster. Furthermore, the procedure could be used to provide justification for subsequent, more intensive local investigations to fully quantify the risk to people and property at stream fan and watershed locations in such areas.

>Magister Scientiae - MSc / The analysis of what controls why rivers are the way they are, and how and why they change is crucial in predicting river dynamics and deriving classification systems that can assist management. A variety of factors control the pattern of fluvial styles in a river system across spatial scales. The geomorphic response of a river to an individual control, such as stream power for example, will vary due to a combination of other contributing factors such as geology and climate.

Logan Canyon is located east of Logan, Utah, in the Bear River Range. The lower part of Logan Canyon is considered that section of the canyon from its mouth upstream to Tony Grove Canyon, a distance of 22 miles, Figure 1 Some tributary canyons of the lower part of Logan Canyon have been included in this investigation because of their relationship to Logan Canyon. Grassy Flat Canyon, a south tributary of Logan Canyon 4.4 miles from Logan, exhibits several geomorphic features related to the geology of Logan Canyon. Because of its extensive use and close association with Logan Canyon, Tony Grove Canyon is also included. Tony Grove Canyon extends from Logan Canyon northwestward to the crest of the Bear River Range, a distance of about six miles. More than 20,000 feet of Paleozoic rocks ranging in age from Cambrian to Pennsylvanian are exposed in Logan Canyon . Cenozoic deposits are widespread in and near the canyon. The crest of the Bear River Range near Naomi Peak and Tony Grove Canyon was the center of glacial activity during the Pleistocene. During the glaciations of Tony Grove Canyon, Lake Bonneville extended into Logan Canyon and influenced the geomorphic development near the mouth of the canyon. Logan Canyon is vital to the economy of Cache Valley. The canyon is a large part of the Logan River watershed. Logan River passes through three hydroelectric plants in Logan Canyon and supplies culinary and irrigation water for the valley below. Animals and plants of a wide variety are abundant, providing fishing , hunting, and a harvest of forest products. U.S. highway 89 traverses the canyon and carries a large volume of traffic to points within the canyon, as well as to other areas. Logan Canyon is entirely within the Cache National Forest. Improved campsites and recreational facilities, which were used by almost 1.5 million visitors during 1963; according to the U. S. Forest Service, are located throughout the Canyon. Increased recreational and travel use of the canyon has resulted in a demand for more geologic work in this area .

Emerging "Structure-from-Motion" (SfM) photogrammetry techniques encourage faster, cheaper, and more accessible field methods for accurately reconstructing 3D topography. The SfM method consists of collecting sets of overlapping images of the ground surface with a point and shoot camera, and reconstructing surface topography from the images with developed software programs. This research develops and implements a SfM image acquisition method and post-processing workflow as a supplemental technique to the traditional total-station method to aid in monitoring sandbar change in Marble and Grand Canyons along the Colorado River in Arizona. Due to permitting in Grand Canyon National Park, a 4.9 m pole-mounted camera platform was used in this research to mimic the ground perspective of an aerial platform. This research presents an improved understanding of how the low-angle, pole-mounted camera platform affects image acquisition and ultimately 3D reconstructions of the surface topography. Models of ground surfaces always contain some degree of elevation error, or uncertainty. As such, elevation error models are needed to distinguish whether observed changes to topographic features (in this case sandbars) are real or simply due to elevation error. There are many ways to quantify multiple sources of elevation uncertainty, but in this study the sources of elevation uncertainty were considered to vary across the surface and were characterized accordingly. Especially in river environments with complex surface topography (e.g. steep cut banks), and roughness (e.g. vegetation), quantifying the spatially variable elevation uncertainty of the surface representation is critical for interpreting actual changes in surface topography over repeat surveys. This research: used the sandbar images collected in Marble and Grand Canyons with the pole-mounted camera platform to generate SfM, topographic models; calculated spatially variable surface uncertainty derived from slope and roughness using multiple statistical analyses; built an error model that was calibrated based upon the statistical analyses of the spatially variable surface uncertainty; Key findings of this research are: Densely vegetated topography results in high amounts of elevation uncertainty, and without additional information of the surface underlying the vegetation, the SfM tool is less operational in these areas; Bare, exposed topography with low to high slopes that are not covered in black shadows result in lower surface uncertainty, and are areas where SfM is an operational tool for studies of surface change. Complementing existing topographic sampling methods with more efficient and cost- effective SfM approaches will contribute to the understanding of changing responses of the topographic features. In addition, the development and implementation of SfM and corresponding amounts of elevation uncertainty for monitoring geomorphic change will provide a methodological foundation for extending the approach to other geomorphic systems world- wide.

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.

<p> The open water season of Radstock Bay is less than three months long and varies considerably from year to year. The break-up and ablation sequence of the bay is regular and systematic, commencing with a period of snow melt and run off and continuing until the dramatic evacuation of the ice. This evacuation is dependent on the ice coverage of Lancaster Sound. The ice foot, a feature found often on arctic beaches was found to be larger in areas of more shallow sloping beaches. A sediment size analysis revealed a trend of diminuation of grain size from S. to N. reflecting net sediment transport in that direction. The two major geomorphic events of the 1971 open water, were two storms, both of which had winds from the S.E. that generated 1.0 meter waves which moved sediment from S. to N. The importance of a small pack of ice in the nearshore zone in inhibiting wave action was noted during one of these events. The freeze-up sequence progressed slowly after the advent of sub-freezing temperatures until the temperature of the seawater reached its freezing point, whereupon the rapid covering of the bay with ice ensued.</p> / Thesis / Master of Science (MSc)

<p> Gypsum karst areas in British Columbia and Wood Buffalo National Park, Alta.-N.W.T. are described. Investigation of the geo-hydrology of these areas, particularly specifically the saturation states of rising waters, is demonstrated to be a valuable tool in defining the major geomorphic processes acting. The combination of thermo-dynamic equilibrium studies of the gypsum and limestone processes serves to define zones within which the dominant controls of rock solution can be inferred.</p> <p> The commonly accepted parameters of limestone solution equilibria (Picknett's curves) are examined and shown to be incorrect. Use of the parameters and indices presented in this thesis gives much better accordance with observed characteristics of karst waters. </p> / Thesis / Master of Science (MSc)