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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

An investigation of compound riverine flooding and the influence of anthropogenic drivers within large-scale catchments.

Chilton, William Paul 21 December 2023 (has links)
Water has always been an essential part of human life. It is necessary for every human activity and process. However, this life-sustaining resource can also cause mass destruction and loss of life. As populations grow and floods occur more frequently and at a larger scale, it becomes increasingly crucial to comprehend the variables and processes that surround flood events. Understanding these factors can help us mitigate the risks associated with floods and minimize their impact on communities. This dissertation consists of six chapters which cover two aspects of flooding. The first aspect deals with the sources of flooding events in a multi-regional basin. The second aspect concerns the impact of anthropogenic activity on flooding processes. In the first two chapters, the research motivation is presented, accompanied by a general review of the concepts that govern the research performed. Chapter three provides a statistical analysis of flood incidents based on their location and the prevailing weather conditions. The results of this chapter indicate that there has been a 6% annual increase in flooding each year across the basin of interest, with a staggering 770% increase in the last four years of the study. The main source of this increase is the lower level flood events, which are often the result of human development. Another notable observation in this chapter is that the majority of weather events that led to flooding were non-tropical in nature. Chapter four examines the relationship between land use and flooding by utilizing various statistical and machine learning techniques to identify the types of land use that contribute the most to flooding within the basin. Findings from this chapter include the loss of croplands across the entire basin, with an almost 1:1 replacement with open water surface and urban area, two land uses that produce the most runoff in precipitation events. In chapter five, we present a numerical model of the lower James River Basin in Virginia, which serves as a tool to assess the impact of land use modifications on flooding in the area. From 2004 to 2021, the basin lost over 13-million cubic meters of storage. Finally, chapter six provides an overview of future work and guidance in this area. / Doctor of Philosophy / Accurately predicting the severity and extent of floods is crucial for organizing activities such as evacuation, emergency response, and recovery planning. However, predicting floods can be a daunting task due to the countless basin configurations and various factors that need to be considered, such as slope, land use, development, and infrastructure. In some cases, numerical flood models can only be used in certain areas due to computational limitations, while in others, it may not be possible to use modeling at all. To tackle these challenges, traditional statistical tools can be used to provide information that can be incorporated into local numerical flood models. This text utilizes publicly available data in a series of statistical, machine learning, and numerical modeling tools to examine flooding in the James River Basin. The first three chapters provide a general overview and research motivation followed by a comprehensive history and statistical analysis of storms in the James River Basin over the last 70 years. The remaining three chapters present a method for assessing land use indicators of flooding using traditional statistics and machine learning tools. Finally, a numerical model of the coastal region of the James River Basin is presented, examining the interaction between the ocean and riverine environments during simulated events.
2

Systems analysis of alternative architectures for Riverine Warfare in 2010

Oliveria, Tristan V., Beaver, James W., Mercado, Pedro R., Bucher, Andrew D., Free, Jennifer M., Byers, Richard W. 12 1900 (has links)
Student Integrated Project / Includes supplementary material. / This thesis analyzed the Navy's proposed Riverine Force (RF) structure and capabilities of 2006. Systems Engineering and Analysis cohort 10 (SEA10) developed a cost-effective system of systems which increased battlespace awareness and situational responsiveness for 2010. Riverine missions were decomposed into their functional, physical, and operational architectures using the detect-to-engage sequence. This analysis determined critical RF functions. Critical functions detect and engage were then physically represented by feasible force package alternatives that augmented the baseline RF. SEA10 analyzed these alternatives using agent based models to identify baseline RF capability gaps and provide insights into possible solutions. Reduction of modeling data indicated the baseline force was as effective as some upgraded force packages depending on the measure of performance (MOP) or scenario structure under scrutiny. Sensor augmentation demonstrated significant improvements to baseline performance by increasing battlespace awareness. Weapon augmentation alone did not significantly improve baseline performance by increasing situational responsiveness. Combined sensor-weapon augmentation performed well across all MOP and scenarios. The Unmanned Surface Vehicle (USV) was the most cost-effective alternative. Dedicated helicopter support demonstrated the best performance overall, but was the most costly alternative.
3

Test and evaluation of meshdynamics 802.11 multi-radio mesh modules in support of coalition riverine operations

Russo, Joseph Anthony 06 1900 (has links)
The Coalition Operating Area Surveillance and Targeting System (COASTS) program is a joint project between the Naval Postgraduate School and the Royal Thai Armed Forces (RTARF). The program focuses its research on command, control, communications, computers, intelligence, surveillance and reconnaissance (C4ISR) uses for commercial-off-the-shelf (COTS), state-of-the-art, rapidly scaleable airborne and ground communications equipment, including various wireless network technologies. This research is being conducted in partnership with the RTAF to develop a network and associated devices and applications that potentially may help suppress drug trafficking in the northern Thailand border regions. Commensurately, the U.S. Navy is taking the Global War on Terror (GWOT) lead in coalition Maritime Security Operations and riverine warfare operations. With formation of the new Naval Expeditionary Combat Command (NECC), and its new Riverine Warfare Group, the Navyâ s role takes effect starting in January 2007, and could benefit from this research. This thesis focuses on testing and evaluating the overall performance of the MeshDynamics Multiple-Radio Mesh Modules, operating in the 802.11 wireless frequency spectrum. These modules are key building blocks of meshed networks that provide coverage over an area where riverine and coastal operations are being conducted. The network provides an information source and communications backbone for maritime, ground, and air assets. / US Navy (USN) author.
4

Seasonal and interannual differences in surface chlorophyll stocks and integrated water column chlorophyll stocks in the northeastern Gulf of Mexico

Fletcher, William Wallerich 01 November 2005 (has links)
During the Northeastern Gulf of Mexico Chemical and Hydrography study (NEGOM-COH), nine oceanographic cruises were fielded during the spring, summer and fall seasons from November 1997 to August 2000. Surface chlorophyll-? fluorescence, salinity, and temperature data were logged once a minute from the R/V Gyre and subsurface chlorophyll-? fluorescence, salinity, temperature, and nutrients were profiled when the ship stopped to make stations. Each cruise occupied 94-98 stations, partitioned among 11 cross-margin transects of water depths between 10 m to 1000 m. Overall chlorophyll-? abundance within the study area is forced by the amount of freshwater discharge. Seasonal and interannual differences are largely determined by the monthly mean streamflow for the major rivers within the NEGOM area, particularly the Mississippi River. However, an important forcing function for transport of river water to the outer continental shelf and slope is the periodic presence of anticyclonic slope eddies. Especially when these slope eddies were centered south and east of the Mississippi River delta, they entrained and so redistributed low salinity green water to a wider area within the NEGOM region than could be predicted by mean monthly streamflow alone. The mean surface chlorophyll-? concentrations, and in particular the distribution of relatively high surface chlorophyll-? concentrations off-shelf, were strongly dependent upon entrainment of freshwater by these slope eddies, especially during the three summer cruises. Interannual variability in the summertime entrainment of low salinity green water was driven by summer-to-summer differences in sea surface height (SSH) of the slope eddy(s), and in how far they extended on margin. Satellite observations of ocean color showed that freshwater entrainment by anticyclonic eddies persisted for a temporal scale of several weeks each summer. Satellite-derived surface chlorophyll-? concentrations were positively correlated with in situ measurements of surface chlorophyll-?, with greatest agreement between satellite and ship measurements of surface chlorophyll-? at concentrations <1.5 mg/m3. Because subsurface chlorophyll-? concentrations were often elevated at depths greater than the first optical depth, satellite measurements of chlorophyll-? concentration generally underestimated integrated chlorophyll-? standing stocks within the euphotic zone.
5

The art of riverine warfare from an asymmetrical approach /

Willey, Paul F. January 2004 (has links) (PDF)
Thesis (M.S. in Defense Analysis)--Naval Postgraduate School, March 2004. / Thesis advisor(s): Anna Simons, George Lober. Includes bibliographical references (p. 61-64). Also available online.
6

Stygian myth : U.S. riverine operations against the guerrilla /

Freitas, Mark. Treadway, Braddock W. January 1994 (has links)
Thesis (M.A. in National Security Affairs) Naval Postgraduate School, December 1994. / "December 1994." Thesis advisor(s): Jan Breemer. Includes bibliographical references. Also available online.
7

Dynamiska flöden som restaureringsmetod : Hur förändras strandvegetationen med en säsongsanpassning av minimitappningen i den reglerade Juktån? / Dynamic flows as a ecological restoration method : How will the riparian vegegation change by implementing seasonal flow variation in the regulated Jukt River?

Sidenbom, William January 2019 (has links)
Regulation and alteration of streams and rivers have a long history and dams provide us with resources. It also degrades the ecosystems connected to them by cutting off transportation routes and changing the flow regime. Riparian ecosystems have evolved to the natural flow regimes, making them sensitive to hydrological alterations. Riparian plant communities are often species rich and have a positive impact on their surroundings, but are often degraded because of flow alteration. Studies predict that riparian zones will lose species and extent because of climate change, making it increasingly important to manage and restore them.  This report examines the potential effects of two scenarios of a planned re-introduction of natural flow variation in the regulated river Juktån in Sweden. Riparian vegetation composition and cover was inventoried in plots with different amount of yearly flooding to assess current relationships between flooding and riparian vegetation. A rating curve was used to determine the relationship between discharge and river stage. GIS-modeling using LiDAR data and the rating curve made it possible to predict the extent of flooding with the two scenarios, and resulting potential changes in vegetation extent and composition. No significant correlation was found between species richness and number of days flooded under current flooding regime. Positive correlation was however found between elevation and species richness, bare soil and flooding, and vascular plant cover and flooding. The three most species-rich vegetation belts are expected to increase substantially in area with both scenarios, suggesting that positive response is likely with the introduction seasonal flow variation.
8

Território e desenvolvimento: análise da produção de açaí na região Tocantina (PA) / Territory and development: analysis of the açaí production in the area Tocantina (PA)

Corrêa, Rosivanderson Baia [UNESP] 14 August 2017 (has links)
Submitted by ROSIVANDERSON BAIA CORREA null (rosivan@ufpa.br) on 2017-09-30T06:26:40Z No. of bitstreams: 1 T E S E_FINAL.pdf: 5349394 bytes, checksum: e698ed8922f5a1e6e36ce2a439a77a29 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-10-02T16:41:43Z (GMT) No. of bitstreams: 1 correa_rb_dr_prud.pdf: 5349394 bytes, checksum: e698ed8922f5a1e6e36ce2a439a77a29 (MD5) / Made available in DSpace on 2017-10-02T16:41:43Z (GMT). No. of bitstreams: 1 correa_rb_dr_prud.pdf: 5349394 bytes, checksum: e698ed8922f5a1e6e36ce2a439a77a29 (MD5) Previous issue date: 2017-08-14 / O presente trabalho tem como objetivo principal investigar e analisar a produção do açaí (euterpe olerácea martius) na região tocantina no estado do Pará, em particular os municípios de Cametá, Igarapé-Mirí e Oeiras do Pará pertencentes à Microrregião Geográfica de Cametá , por serem estes grandes produtores de açaí. Tendo este produto experimentado nos últimos anos uma grande expansão/aceitação no mercado externo regional, nacional e global. O recorte temporal selecionado se estende de 1990 até os dias atuais, por ser este o momento em que o açaí-fruto, em forma de polpa, começa a ser comercializado fora da região, além do consumo interno na Amazônia. Dessa forma surgem novos produtos a partir da polpa do açaí como o sorvete de açaí, mix, energéticos, refrigerantes etc. As principais problemáticas investigaram quais têm sido as vantagens para as comunidades ribeirinhas que produzem açaí, com a expansão do circuito espacial da produção para os mercados nacional e internacional? Quais têm sido as metamorfoses impressas no território que indiquem mudanças? Quais medidas podem ser adotadas para fomentar o desenvolvimento que beneficie não apenas os comerciantes e as agroindústrias, mas também os produtores de açaí e as comunidades locais? Realizamos a investigação utilizando a pesquisa bibliográfica, a pesquisa de Campo e a pesquisa documental e os resultados apontam que existe perspectiva de desenvolvimento a partir a produção de açaí se aliada a outras atividades, como a pesca e a cultura de outros produtos. / The present work has as main objective to investigate and to analyze the production of the açaí (euterpe olerácea martius) in the area tocantina in the state of Pará, in matter the municipal districts of Cametá, Igarapé-Mirí and Oeiras do Pará belonging Geographical Microrregião of Cametá, for they be these big producing of açaí. Tends that this experienced product in the last years a great expansion in the regional, national and global external market. The selected temporary cutting if it extends from 1990 to the current days, for being this the moment in that the açaí-fruit, in pulp form, begins to be marketed out of the area, besides the internal consumption in the Amazonian. In that way new products do appear starting from the pulp of the açaí as the açaí ice cream, mix, energy, soft drinks etc. which THE main problem investigated the advantages have been for the riverine communities that produce açaí, with the expansion of the space circuit of the production to the national and international markets? Which have the metamorphoses been printed in the territory that you/they indicate changes? Which measures can be adopted to foment the development to not just benefit the merchants and the agribusinesses, but also the producing of açaí and the local communities? We accomplished the investigation using the bibliographical research, the research of Field and the documental research and results point that development perspective exists to break the açaí production if allied to other activities, as the fishing and the culture of other products.
9

The art of riverine warfare from an asymmetrical approach

Willey, Paul F. 03 1900 (has links)
Approved for public release; distribution is unlimited / This thesis examines U.S. riverine warfare from an unconventional perspective in three Latin American countries to include: Bolivia, Colombia, and Peru. U.S. forces in particular NSW was (and remains) instrumental in helping these countries establish riverine units and an active presence on their rivers. These three different programs all have the same mission to deny the uncontested use of the rivers and inland waterways by narco traffickers and insurgent forces for the use of illegal activities. This thesis compares and contrast the three cases and garnishes lessons learned for future endeavors of the same. / Lieutenant Commander, United States Navy
10

Aspects of the invertebrate ecology of the Nwanedzi tributary of the Limpopo River

Mokgalong, Nehemiah Mashomanye January 1981 (has links)
Thesis (M. Sc. (Zoology)) -- University of the North, 1981 / Refer to the document

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