ABSTRACT: Umeå has had its troubles with flooding over the years. This study aims to describe and analyze flooding and stormwater management in the municipality of Umeå in Sweden. How the municipality is handling the responsibility to minimize the risk of flooding in problem areas and how they are planning to prevent flooding with stormwater management methods in both old and new districts of the city. With information gathered from the municipality itself and from other reports and websites of worth, I have compared the results I’ve gotten partly from my own field visits in the areas that are being planned for changes and partly from other reports. With that said, this study is a descriptive study with a focus on comparisons.

Traditionally risk management is associated with identification, evaluation and prioritization of risks. Nonetheless, communication of the risks to the parties involved is of the utmost importance. By providing more complete and easy to perceive information regarding potential hazard impacts and economic losses, risk analysis output increases risk awareness and helps make risk-informed decisions. At present, in the field of civil engineering three-dimensional (3D) models are almost exclusively used for the design of structures. The presence of 3D and Virtual Reality (VR) technologies in risk analysis is extremely scarce. At the same time, there are potential advantages these technologies can provide to risk analysis and communication: the virtual 3D environment can emulate physical space and relationships between elements of the system, time-dependent simulations of hazard propagation, and awareness of physical dimensions of elements and their interconnection can be integrated. This work is concerned with the way to communicate risks associated with building systems to decision-makers by visualizing them on a 3D model of construction and through simulation in a VR environment. For this purpose, the Almonte Power Plant in Mississippi Mills, Ontario, is analyzed as a case study. It is a small scale hydropower plant that is at risk of flooding, being located close to the Mississippi River. The last large scale flood in this region occurred in April 2019. The novel methodology is applied to the aforementioned case study and further experiments are performed to test the sensitivity of the model to various parameters. The parameters of interest are flow rate and the degree of dependency between elements. Risk scores are obtained and evaluated as a function of flow rates and duration from the onset of flooding. The change in the degree of dependency between various elements of the electrical system allows an illustration of the importance of expert judgement of those dependencies. / Graduate / 2021-05-20

Research trials performed in the greenhouse compared the tolerance and response of Hordeum jubatum and desirable pasture grass species to herbicides, salinity, and flooding. Desirable grass species used in this study included: `Fawn' tall fescue (Festuca arundinaceae), `Garrison' creeping foxtail (Alopecurus arundinaceus), `Palaton' reed canarygrass (Phalaris arundinacea), `Climax' timothy (Phleum pratense), `Alkar' tall wheatgrass (Thinopyrum ponticum), `Potomac' orchardgrass (Dactylis glomerata), and `Mustang' altai wildrye (Leymus angustus). Tolerance to herbicides, salinity, and flooding varied significantly among grass species. Herbicide tolerance was tested using four herbicides at five rates each. The herbicides used were imazapic (Plateau), propoxycarbazone (Olympus), sulfosulfuron (Outrider), and flucarbazone (Everest) at rates of 0, 10, 25, 50, 100, and 200 g ha-1. Foxtail barley was least tolerant of sulfosulfuron and propoxycarbazone. Tall fescue, creeping foxtail, and reed canarygrass were susceptible to all the herbicides tested. Timothy and foxtail barley were moderately tolerant while tall wheatgrass exhibited the greatest tolerance to flucarbazone. Orchardgrass was most tolerant to propoxycarbazone. Salinity tolerance was determined by exposing grasses to increasing electrical conductivity (EC) over time. Reed canarygrass and timothy were most susceptible to salinity. Orchardgrass, creeping foxtail, and tall fescue were moderately tolerant of salinity. Foxtail barley, altai wildrye, and tall wheatgrass exhibited the highest tolerances to salinity, and continued to persist at the highest EC levels tested. Flooding tolerance was determined by flooding grasses in 18 cm of water for 2, 4, 6, and 8 weeks. Grasses that were able to extend above the water surface survived, whereas plants that failed to extend beyond the water surface experienced higher mortality rates.

No description available.

Northern boreal alluvial meadows are ecologically significant semi-natural ecosystems within the riparian zone. The effects of disturbance like flooding, grazing, and mowing have historically maintained high nutrient turnover and succession disruption that led to high biodiversity, leading to their inclusion in the Natura 2000 network. Today, alluvial meadows are threatened by human abandonment and river flow regulations, both of which provided necessary disturbances. This leads to encroachment by woody plants and a significant reduction in biodiversity. The purpose of this project was to investigate the hydrological conditions required for the long-term maintenance of floodplains of the regulated lower Dal River and how varying water levels affect the species distribution and various vegetation characteristics. This was done by examining plant data from 3 sites in an alluvial meadow in Bredforsen and datalogger water level data to calculate the duration of flooding of plots in a transect study. The effects of altitude, flooding durations, and frequencies on species richness, proportion of woody plants, and vegetation cover were examined. Flooding times showed the most significant effects on vegetation characteristics, while altitude and flooding frequencies differed greatly between sites, with variability explained being low for all explanatory variables. On one hand, this shows that that a lack of seasonal flooding has a negative effect on the alluvial meadow ecosystem and an increase in water flow would be beneficial. On the other hand, the low degree of explained variability implies that flooding solely is not the determining factor and other management methods are necessary to maintain the alluvial meadows.

The continued spread of Palmer amaranth (Amaranthus palmeri S. Wats.) throughout the southern and midwestern United States is a result of herbicide-resistant populations. Besides being the most troublesome weed specie in several agronomic crops, Palmer amaranth is also host to economically important pests such as tarnished plant bug (Lygus lineolaris Palisot de Beauvois). Pesticide application methodology that maximizes efficacy while reducing selection pressure is needed to combat herbicide-resistant Palmer amaranth. Pulse width modulation (PWM) sprayers are used for pesticide application with the goal of maintaining product efficacy while mitigating spray drift. Additionally, alternative off-season weed management practices such as flooding could be adopted to optimize soil seedbank depletion. Therefore, evaluation of spray droplet size and flooding period on Palmer amaranth control and seed germination was conducted. The objectives of this research were to: (1) evaluate the influence of spray droplet size on lactofen and acifluorfen efficacy on Palmer amaranth using a PWM sprayer, (2) develop prediction models to determine spray droplet size that provides the greatest level of Palmer amaranth control, (3) evaluate the impact of flooding period and seed burial depth on Palmer amaranth seed germination in different soil textures, and (4) analyze the impact of nitrogen fertilizer application rate on the attractiveness of Palmer amaranth to tarnished plant bug. Results show that spray droplet size does not affect lactofen efficacy on Palmer amaranth, thus, coarser spray droplets are recommended to increase spray drift mitigation efforts. In contrast, acifluorfen applied with 300 μm (medium) spray droplets provided the greatest Palmer amaranth control. Furthermore, prediction models indicated that greater model accuracy was obtained when adopting a location-specific weed management approach. Flooding periods of 3, 4, and 5 months reduced Palmer amaranth seed germination across burial depths and soil textures. Therefore, fall-winter flooding may be adopted as an effective practice for soil seedbank depletion. Results also demonstrated that nitrogen fertilizer application rate does not consistently impact Palmer amaranth attractiveness to tarnished plant bug.

Tropical Storm Irene’s most extreme rainfall resulted in record-breaking sediment loads from upland tributaries to the Connecticut River. However, was the event exceptional with respect to resultant deposition downstream? Off-river waterbodies to the Lower Connecticut River, such as cut-off meanders and blocked valley lakes, are a particularly important floodplain environment, which have been shown to serve as a focal point for the trapping of sediment and associated contaminants. This study evaluates the relative role of extreme events like Tropical Storm Irene in infilling these off-river environments. To meet this objective we compare the magnitude and composition of resultant sedimentation from Irene to that observed following the 2011 and 2013 spring freshets. Tropical Storm Irene deposits were identified as compositionally distinct, grey layers that were relatively inorganic compared to sediments deposited by the annual spring freshet. Sediment within the Irene deposit was enriched in elemental potassium and depleted in zircon, a finding consistent with being enriched by glacigenic lacustrine and till sediments. Decreased mercury levels in the Irene deposits suggest that this event served to cap highly contaminated, industrial era sediment with a layer of relatively clean, fine-grained silt and clay. Resampling of these waterbodies in Fall 2012 revealed preservation of the 2-3 cm thick Irene deposit as well as 3-4 cm of more recent sediments deposited on top of this event. Sediment contributions from rare events, like Tropical Storm Irene, were found to be less influential than the annual spring freshet in the long-term infilling of waterbodies along the Lower Connecticut River. However, sediments from Irene are compositionally unique and serve to highlight the importance of this event in removing glacially derived fines from the river’s upland catchments.

Dodder (Cuscuta gronovii Willd.) is a weed of serious concern to cranberry (Vaccinium macrocarpon Ait.) growers. It develops vigorously and has a long-lived seed bank. Cranberries are a perennial crop and therefore strategies available to growers of annual crops are not practical. Herbicides, the primary management tool for dodder, although effective, have a narrow window of application and extended seedling emergence after applications can result in escapes. This project examined the effect of water temperature on dodder seed germination and the use of short-term floods (less than 72 hr) for dodder management. Experiments investigated the effect of water temperature on dodder seed germination. Studies, ran twice, submerged dodder seed in water for 0 to 48 hr at 10, 15, and 20 C in one experiment (simulating spring water temperatures) and 0 to 48 hr at 15, 20, and 25 C in a separate experiment (simulating summer water temperatures). In Run 1, the effect of temperature on percent seed germination varied by flood duration; and by temperature alone in Run 2. Percent seed germination however, always fell within normal ranges (35-59%), indicating that flooding may not impact seed germination. Two 1-yr field studies were conducted to evaluate the use of short-term floods (24 to 48 hr) for managing dodder in cranberries. Two scenarios were simulated: cranberry beds with no emergent weed populations (cranberries alone) and cranberries with emergent weed populations (cranberries with additional host). There were three flood durations (0, 24, and 48 hr) and four flood initiations (1 to 4 wk after first seedling emergence). In 2006, mean percent germination from seeds incubated in Petri dishes was lower for seeds submerged 3 and 4 wk after first emergence (AFE) for the 48-hr flood durations. In 2007, mean percent germination for seeds submerged for 24 and 48-hr decreased for floods initiated at 4 wk AFE. Flooding 4 wk AFE resulted in lowest mean attachment ratings in both years and lowest mean dodder biomass on cranberry in the 2007 cranberry and tomato study, suggesting later flood initiation may provide better dodder management.

Polymer flooding is one of the most used chemical methods for enhanced oil recovery(EOR). However, laboratory studies and field applications of polymer injections often encounter polymer-induced clogging due to polymer transport and entrapment, leading to permeability reduction and diminished recovery performance. In this work, we focus on understanding polymer flow behavior using microfluidics devices and fluorescence microscopy. Microfluidic devices were designed to mimic and replicate the pore-network structures of oil-bearing conventional reservoir rocks. We present various flow experiments to study polymer transport and the underlying mechanisms of polymer retention in porous media. We assess the polymer-induced clogging of partially hydrolyzed polyacrylamides - HPAMs, using tracers. Afterward, we use a commercially available fluorescent polymer with microfluidics and single-molecule microscopy to give insights into individual molecule dynamics. Furthermore, we perform numerical simulations to replicate and extend the experimental work. As these experiments were conducted using commercially fluorescent polymer of low molecular weight and due to limitations of tracers to track polymers, we extended this work to investigate the transport of HPAMs, which is the most used polymer for EOR, at molecule-scale. However, existent methods in the literature are not suitable for fluorescently labeling ultra-high molecule weight polymers. Therefore, we present a novel method for synthesis of dye-labeled polymers that successfully tagged the HPAMS. Finally, we assessed the conformation and flow dynamics of the fluorescently labeled HPAM molecules. The findings highlight a limitation in some polymer screening workflows in the industry that suggest selecting the candidate polymers based solely on their molecular size and the size distribution of the rock pore-throats. Moreover, we present, for the first time, direct visualization of the three main mechanisms underlying polymer retention in porous media. We bring the first molecular evidence of polymer pore-clogging and permeability reduction reversibility, which sheds light on the controversy in the literature. In addition, we propose a new method for fluorescent labeling water-soluble ultra-high molecular weight polyacrylamides-based polymers that preserves their viscosifying properties. The method can be extended to any polymers containing carboxyl groups or groups that can be functionalized into carboxyls, and therefore, the applicability covers any fields that employ polymers.

The expected increase in precipitation and temperature in Scandinavia, and especially short-time heavy precipitation, will increase the frequency of flooding. Urban areas are the most vulnerable, and specifically, the road infrastructure. The accumulation of large volumes of water and sediments on road-stream intersections gets severe consequences for the road drainage structures. The need for a tool to identify characteristics that impacts the occurrence of flooding, and to predict future event is thus essential. This study integrates the spatial and temporal soil moisture properties into the research about flood prediction methods. Soil moisture data is derived from remote sensing techniques, with focus on the soil moisture specific satellites ASCAT and SMOS. Furthermore, several physical catchments descriptors (PCDs) are used to identify catchment characteristics that are prone to flooding and an inventory of current road drainage facilities are conducted. Finally, the index of sediment connectivity (IC) by Cavalli, Trevisani, Comiti, and Marchi (2013) is implemented to assess the flow of water and sediment within the catchment. A case study of two areas in Sweden, Västra Götaland and Värmland, that was affected by severe flooding in August 2014 are included. The results show that the method with using soil moisture satellite data is promising for the inclusion of soil moisture data into estimations of flooding and the index of sediment connectivity. / De förväntade ökningarna i nederbörd och temperatur i Skandinavien, och speciellt extrem korttidsnederbörd, kommer att öka frekvensen av översvämningar. Urbana områden är de mest sårbara, och speciellt väginfrastrukturen. Ackumuleringen av stora volymer av vatten och sediment där väg och vattendrag möts leder till allvarliga konsekvenser för dräneringskonstruktionerna. Behovet av ett verktyg för att identifiera egenskaper som påverkar förekomsten av översvämningar, och för att förutsäga framtida händelser är väsentligt. Studien integrerar markfuktighet både rumsligt och tidsmässigt i forskningen om metoder för översvämningsrisker. Markfuktighetsdata är inkluderat från fjärranalysteknik, med fokus på de specifika satelliterna för markfuktighet, ASCAT och SMOS. Vidare är flertalet faktorer (PCDs) inkluderade för att identifiera egenskaper i avrinningsområden som är benägna till översvämning samt en inventering av nuvarande vägdräneringskonstruktioner. Slutligen är ett index med sediment connectivity (Cavalli et al., 2013) implementerat för att se flödet av vatten och sediment inom avrinningsområdet. En fallstudie med två områden i Sverige, Västra Götaland och Värmland, som drabbades av allvarliga översvämningar i augusti 2014 är inkluderat. Resultaten visar att metoden att använda markfuktighet från satellitdata är lovande för inkludering i uppskattningar av översvämningsrisk och i indexet med sediment connectivity.