The Bac Hung Hai zone is the greatest basin in the Red River Delta in Vietnam and also one of the most densely populated regions of the planet. It is mainly a rural region and its economy is dominated by agriculture. In the context of frequent and larger floods in the Bac Hung Hai zone, causing deep socio-economical consequences, the focus of this study is to establish cartography of the high risk areas for flooding in the Bac Hung Hai region using remote sensing and GIS to assist land management. The preparation of a map describing land management in this region is more complicated because parcels for farming are very small and not homogeneous. A consistent and precise map of land use is essential for studies of flooding. The secondary objective is to improve the land use map. To this effect, a classification has been applied to the combination of the spectral bands and textures (TM and ETM[indice supérieur +]) of Landsat and a radar image (ERS). The addition of this information to the spectral bands increases the accuracy of classification by 1% to 4%, according to the dates selected. Additionally, in the study zone where there are few days without clouds, a problem related to the optical satellite image is the cloud cover. Then, the use of radar images will provide ground information for areas hidden by clouds where spectral images are not sufficient. To reach these goals, we have determined the main biophysical considerations that influence flooding. Then, these considerations have been combined in a multi-criteria analysis to evaluate the risks of flooding in the entire basin area. The results show that high to very high risks affect 47% of the area studied and that the south-east region, center, and north-east present the greatest risk.

Metamorphic rocks constitute a vast volumetric proportion of the Earth’s continental lithosphere and are invaluable recorders of the mechanisms and rates of deformation and metamorphism that occur at the micro-, meso- and macro-scale. As such, they have the potential to provide detailed insight into important tectonic processes such as the subductive transport of material into, and back from, mantle depths and also folding, faulting and thickening of crust that occurs during collisional orogeny. The Himalayan-Karakoram-Tibetan orogen is the youngest and most prominent example of a continent-continent collisional mountain belt on Earth today and is a product of the on-going convergence of the Indian and Asian plates that initiated in the Early Eocene. Thus, it provides an exceptional natural laboratory for the investigation of such processes. Recent advances in the computational ability to replicate natural mineral assemblages through a variety of metamorphic modelling techniques have led to improvements in the amount (and quality) of petrographic data that may be obtained from a typical metamorphic rock. In this study, phase equilibria modelling (pseudosection construction) using THERMOCALC, amongst other techniques, has been integrated with in-situ U–Pb and Th–Pb geochronology of accessory monazite in order to constrain the tectonothermal evolution of four regions intimately associated with the Himalayan-Karakoram-Tibetan orogen. These regions comprise the Karakoram metamorphic complex (north Pakistan), the Tso Morari massif (north-west India), the eastern Himalayan syntaxis (south-east Tibet) and the Day Nui Con Voi metamorphic core complex of the Red River shear zone (North Vietnam). Each case study documents previously unreported metamorphic, magmatic or deformational events that are associated with the India-Asia collision. These data have allowed original interpretations to be made regarding the tectonic evolution of each individual region as well as the large-scale evolution of the Himalayan-Karakoram-Tibetan orogenic system as a whole.

Manitoba’s flooding is one of the principal sources of costs associated with flood disasters. Despite the tremendous financial investments in structural mitigation, flood cost, continue to rise. Currently at the national and provincial level, there exists no standardized operational framework and tool for flood risk assessment. The primary role of this research was two-fold. First, Hazus-MH a Quantitative Risk Assessment (QRA) tool was evaluated as a potential flood-loss estimation model in a Manitoba context. Secondly, to examine the application of a QRA tool in policy, a face-to-face questionnaire was completed with flood experts in municipal and provincial government and with consultants. The study results suggested that Hazus-MH has the potential to be applied as a standard QRA tool in Manitoba. This research found that developing a standard QRA tool in Manitoba, would empower communication between decision-makers, centralize data to support disaster planning, and reduce the cost of recovery. / May 2016

Video summarizing a Ph.D. dissertation for a non-specialist audience. / Emergency Management / Emergency Management / College of Arts, Humanities and Social Sciences

Late Ordovician Red River strata of southeastern Saskatchewan were deposited in a broad epicontinental sea. In the lower part, the Yeoman and Herald formations comprise two cycles of carbonateevaporite sequences. Although these units possess an overall layer-cake aspect, thickness variations especially in the Herald Formation show that accumulation was affected by syndepositional flexure, differential subsidence and displacement of fault-bounded blocks. The mainly laminated dolomudstones and anhydrites of the Lake Alma and Coronach members of the Herald Formation were deposited under relatively tranquil conditions. These units host different kinds of synsedimentary deformation features, interpreted to have been induced by earthquakes generated because of movements along basement faults thought to have been oriented orthogonally NE−SW and NW−SE. The low-energy environmental setting was conducive to preserving these features, referred to as seismites.<p> The variety of seismites in the Herald Formation is related to the varying rheology of the carbonate or evaporite sediment, as well as shaking intensity. Brittle and quasi-brittle failure is represented by faults, microfaults, shear-vein arrays and pseudo-intraclastic breccias, mostly in dolomudstones which must have been stiff at the time of deformation. Plastic behaviour is recorded by soft-sediment deformation, comprising a family of features that includes loop bedding, folded laminae and convolute bedding. Indeed, these structures in enterolithic anhydrite are more reasonably interpreted as due to deformation than crystal growth, volume expansion and displacement, the more usual explanations. Sediment shrinkage and concomitant fluidization are recorded by dikelets containing injected carbonate mud or granular gypsum, the latter now preserved as anhydrite. Evidence for wholesale liquefaction, however, was not observed. These rheological differences were caused by the primary nature of the sediment plus modifications due to early diagenesis and burial confinement. Shaking intensity is difficult to gauge, but it is presumed that a minimum of VI on the modified Mercalli scale was required to produce these features. Consequently, shaking of lesser magnitude was probably not recorded.<p> The geographic distribution of seismites should reflect the location of basement faults presumed to have been active during deposition, and indeed there is a concentration adjacent to the known location of syndepositonal fault lineaments. In addition, the stratigraphic distribution of seismites records higher frequencies of activity of these same faults. These distributions show that earthquake-induced ground motion was common during deposition of the Lake Alma Member in southeastern Saskatchewan but less so during deposition of the Coronach Member.<p> Seismites serve as proxies for the activity of relatively nearby syndepositional faults making up the tectonic fabric of sedimentary basins. They also point to basement features that, if re-activated, can induce fracture porosity or influence subsurface fluid flow. Syndepositional tectonism undoubtedly had a much more profound influence on many successions than is presently accepted, and its effects are more widespread than currently appreciated.

Thesis (Ph.D.)--Texas Christian University, 2009. / Title from dissertation title page (viewed July 8, 2009). Includes abstract. Includes bibliographical references.

Postglacial rivers are part of the relatively young low-relief landscape system left behind by glaciers. Over time, postglacial rivers are susceptible to both minor and major channel planform changes as the Earth and its newly exposed rivers adjust to new isostatic and geomorphic equilibriums. Those planform changes result in topographic features that are well preserved among the largely unaltered landscape and offer opportunities to learn about the processes that create them. This work focuses on those minor and major planform changes and the resulting landforms, with a focus on processes effecting the glaciolacustrine Red River Valley. Here, three studies were conducted, two regarding minor planform changes and one focusing on major planform changes. Studies included in this work regard 1) the spatial distribution of meander cutoffs and meander cutoff relief on the Red River, 2), avulsion timing and length resulting from isostatic tilting and 3) mobile river ice and bank interaction frequency, locations, and erosion in meandering rivers. Results show that rivers develop meander cutoffs that faster in areas where geologic materials are more easily eroded and their relief shows a positive relationship with the rate of river incision. Major channel path changes (avulsions) in the presence of isostatic tilting were found to be most frequent soon after river establishment while rates of isostatic rebound are high enough to outpace channel incision. River ice was found to most frequently interact with the outer banks of channels with long, tight bends and high sinuosity, potentially contributing to the meandering process. From these results it can be interpreted that postglacial rivers were highly dynamic early in their history and have stabilized over time, with most of the changes occurring in areas with more erodible alluvium. Presently, rivers undergo most of their changes during the spring thaw when mobile river ice is impacting the banks, with sinuous river reaches impacted most frequently by mobile river ice. / North Dakota Water Recourses Research Institute (ND WRRI) Fellowship Program

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No description available.

Excessive soil moisture can impact planting date, plant establishment, and N availability, resulting in reduced yields and N use efficiency. Nitrogen management practices such as use of urease and nitrification inhibitors, and split applications may be used to reduce N lost during the growing season, improving N use efficiency and crop productivity. The objective of this study was to determine whether N management practices could improve corn (Zea mays L.) productivity with or without subsurface drainage on a fine-textured clay soil in eastern North Dakota. Five field trials were conducted in 2009 and 2010 in eastern North Dakota. Treatments consisted of a factorial combination of N management practices [urease inhibitor n-(n-butyl) thiophosphoric triamide (NBPT), starter fertilizer, nitrification inhibitor 2-Chloro-6-(trichloromethyl) pyridine (nitrapyrin), and split applications], N rates (56, 112, 168, and 224 kg N ha-1), and the presence of subsurface drainage (two environments). In both 2009 and 2010 there was no grain yield differences among drainage treatments. Differences in grain yield were observed with different N rates. Nitrogen management practices also affected grain yield. The interactions between N management practices and drainage were not significant. End of season stalk nitrate content showed differences in N availability with different N rates, but not N management practices. Neither NBPT nor the starter fertilizer significantly increased yield over the untreated check in any environment. Nitrapyrin significantly increased yield over the untreated check at Fargo in 2010. Increased N rates resulted in greater corn grain protein.