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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

Development of an Oil Spill Emergency Mapping System Using Internet GIS

Gomes, Gary January 2010 (has links)
ince the 1970s, environmental monitoring in China has formed a complete web across the country with over 2000 monitoring stations. China State Environmental Protection Administration (SEPA) has published an annual report on the State of the Environment in China since 1989. The Chinese government began to inform the public of environmental quality and major pollution incidents through major media since the late 1990s. However, environmental quality data has not been adequately used because of constraints on access and data sharing. The public and interested groups still lack access to environmental data and information. After examining the current air quality reporting systems of the US Environmental Protection Agency and the Ontario Ministry of Environment, reviewing current Internet GIS technology and sample websites, this thesis developed an ArcIMS website to publish air quality data and provide background information to the public for the city of Dalian, China. The purpose is to inform the public of daily air quality and health concerns, and to improve public awareness of environmental issues. A better-informed and educated public will be more likely to voluntarily conserve the environment in the long run. The development of this thesis can satisfy most basic expectations. However, due to the limitation of current Internet products like ArcIMS, symbology and connection with outside databases are not adequate. In addition some regular GIS analysis functions are not available to Internet GIS products. This development can be further improved to serve other environmental data to the public with better interactivity through coding. Similar Internet GIS products can be used in other Chinese cities to report their air quality data. For internal data sharing and reporting within the government, an open, interoperable distributed GIService is recommended, which is believed to be the future of Internet GIS.
2

Vulnerability of Larval Fish Populations to Oil Well Blowouts in the Northern Gulf of Mexico

Chancellor, Emily 01 January 2015 (has links)
On April 20th, 2010, a fire broke out on the Deepwater Horizon (DWH) offshore oil drilling rig on the Macondo prospect located off the coast of the Gulf of Mexico (GOM). This fire and resulting explosions resulted in the sinking of the Deepwater Horizon rig and the largest marine oil spill in history. An estimated 4.9 million (+/- 10%) barrels were released into the Gulf of Mexico over the ensuing 87 days. Many economically important fish species spawn in northern Gulf of Mexico waters; the spawning seasons and pelagic larval phase of many of these species occur within the temporal extent of the DWH oil spill (April through July). Fish eggs and larvae in waters exposed to Macondo oil likely experienced lethal and sublethal physiological effects, leading to potential losses in year class strength depending on the proportion of a population’s larval production encountering oil. Differing spatial distributions of larvae due to different spawning locations and seasons could predict that some species were disproportionately affected by the DWH oil spill. This study aims at quantifying the impact of the spill across numerous taxa, by estimating the proportion of species-, genus-, or family-specific fish larval abundances located within the spatial/temporal domain of the DWH spill until the Macondo well was capped. Estimates and related uncertainties were based on empirical ichthyoplankton data collected over 27 years and on observed and modeled distribution of surface oil slicks and concentrations. In addition, two hypothetical oil spills were simulated on the Western Florida Slope and on the Western interior of the Gulf of Mexico to assess the impact of oil spills to the ichthyoplankton from different offshore locations that would have occurred during the DWH spill period. Ichthyoplankton data collected during annual plankton surveys (and other resource surveys) as part of the Southeast Area Monitoring and Assessment Program – Gulf of Mexico (SEAMAP) during years 1982-2009 were used to describe the composition and distribution of ichthyoplankton in the northern Gulf of Mexico. The SEAMAP larval fish data along with oil surface distributions (both actual and simulated) were used to estimate the proportions of larvae of 115 selected fish taxa that were potentially exposed to DWH oil. Bootstrapping methods were applied to the SEAMAP data to quantify the variability. Proportions of larval fish potentially exposed to oil were calculated for four oil spill scenarios: (1) the DWH spill, (2) an September-December oil spill with the same spatial footprint as the DWH spill but occurring later in the year, (3) a west Florida Slope spill occurring during the months of April-July and centered at 27˚N, 85˚W, and (4) a western GOM spill occurring during the spring and centered at 27˚N, 93.5˚W. Spill scenarios (3) and (4) were modeled using the Connectivity Modeling System (CMS). The CMS is a Lagrangian model which predicts oil droplet distribution and degradation based on oil properties and ocean currents. Significant differences in the proportion of larvae potentially exposed were found in the DWH spill and the three simulations. The proportion of fish larvae exposed to the DWH spill varied between 0% (many species) and 26.8% (Cynoscion nebulosus). The proportion of fish larvae exposed to simulated spills varied between 0% and 78.9% (Bonapartia pedaliota in Western GOM spill). Both the west Florida Slope oil spill and the western GOM spills had a disproportionally greater impact on a larger number of taxa than the DWH spill, even after correcting for their larger spatial extent. For the DWH spill (Scenario 1), the potentially most impacted taxa were Cynoscion nebulosus, Engraulidae, Rachycentron canadum, and Etropus spp. If the DWH spill had occurred in the fall (Scenario 2), the most potentially impacted taxa would have been Leiostomus xanthurus, Elopidae, and Pomatomus saltatrix. For a west Florida slope exposure (Scenario 3), the potentially most impacted taxa would be Holocentridae, Acanthocybium solandri, Coryphaena spp., and Pomacanthidae. For a western GOM spill (Scenario 4), the most potentially impacted taxa would be Bonapartia pedaliota, Thunnus thynnus, Caranx spp., and Holocentridae.. The historical SEAMAP data set combined with the CMS modeling tool provides a powerful planning tool to understand the potential impacts of oil spills in the northern GOM and the relative sensitivity of locations in the Northern GOM to oil spill effects.
3

Development of an Oil Spill Emergency Mapping System Using Internet GIS

Gomes, Gary January 2010 (has links)
ince the 1970s, environmental monitoring in China has formed a complete web across the country with over 2000 monitoring stations. China State Environmental Protection Administration (SEPA) has published an annual report on the State of the Environment in China since 1989. The Chinese government began to inform the public of environmental quality and major pollution incidents through major media since the late 1990s. However, environmental quality data has not been adequately used because of constraints on access and data sharing. The public and interested groups still lack access to environmental data and information. After examining the current air quality reporting systems of the US Environmental Protection Agency and the Ontario Ministry of Environment, reviewing current Internet GIS technology and sample websites, this thesis developed an ArcIMS website to publish air quality data and provide background information to the public for the city of Dalian, China. The purpose is to inform the public of daily air quality and health concerns, and to improve public awareness of environmental issues. A better-informed and educated public will be more likely to voluntarily conserve the environment in the long run. The development of this thesis can satisfy most basic expectations. However, due to the limitation of current Internet products like ArcIMS, symbology and connection with outside databases are not adequate. In addition some regular GIS analysis functions are not available to Internet GIS products. This development can be further improved to serve other environmental data to the public with better interactivity through coding. Similar Internet GIS products can be used in other Chinese cities to report their air quality data. For internal data sharing and reporting within the government, an open, interoperable distributed GIService is recommended, which is believed to be the future of Internet GIS.
4

The Mechanism of Long-Term Environmental Impact Assessment for Large Oil Spill Events

Tsao, Kai 19 October 2011 (has links)
Ever since humans began using cargo by sea to transport oil, oil spill incidents have occurred on different scales in different environments. Oil leaks by cargo tankers on the high seas have a bigger and more serious impact on the environment. Among the many oil spills in the ocean, the most serious was the Exxon Valdez incident in Alaska¡¦s Prince William Sound (PWS). While it may not have been the largest spill in terms of the volume of oil leaked, its effects were far-reaching; the location of the spill was in the sensitive area between the temperate and subtropical zones, and it was home to many fish, migratory birds, and mammals. Therefore, this location has become an important place for researchers to study the environmental and biological impacts of an oil leak. In the past, there have been several studies conducted from various perspectives and in various stages. In 2001, the Greek oil tanker The Amorgos ran aground near Kenting National Park¡¦s Long-Keng Environmental Protection Zone and seriously damaged the ecological environment. Taiwanese studies on the ecological impacts of oil spills include investigations and evaluations done on a short-term basis, and have been mainly focused on contingency plans and designs, evaluation systems, and handling technology. Thus, the purpose of this paper is to use related studies conducted in Alaska PWS to evaluate the ecological system in the Long-Keng area and to assess the long-term impacts of an oil spill in the ecological sensitive area of Taiwan.
5

Hydrocarbons in the open ocean waters near the Galician Bank after the deep sea spill from the Prestige wrecks

Elordui-Zapatarietxe, Saioa 03 June 2009 (has links)
Hoy en día existe una escasez de estudios sobre la distribución de los hidrocarburos en mar abierto, aunque el aumento de la explotación de yacimientos de petróleo y la intensificación del tráfico marítimo más allá de la plataforma continental haya aumentado. Asimismo, se han identificado nuevas fuentes de contaminación. En los últimos años se ha puesto en evidencia el alto número de barcos hundidos en los fondos marinos que podrían potencialmente generar futuros vertidos de petróleo. En esta tesis, se investiga el accidente del petrolero Prestige cerca de Galicia en el 2002 como caso de estudio de un vertido marino en profundidad en mar abierto, ya que aproximadamente unas 43.000 toneladas de fuel oil pesado que llevaba a bordo fueron vertidas una vez el barco de rompió en dos y se hundió. Además, la zona del hundimiento del Prestige es un área hidrodinámicamente compleja. La columna de agua esta formada por cinco masas de aguas principales, de diferente origen y con características físico-químicas diferentes, que pueden contribuir activamente extender el fuel liberado por el Prestige en las aguas cerca del Banco de Galicia. En este contexto, el principal objetivo de la presente tesis ha sido determinar la importancia de los pecios del Prestige como fuente de contaminación en las aguas cerca del Banco de Galicia varios años después del accidente e investigar el papel de las masas de agua en el transporte y distribución de los hidrocarburos en la zona del hundimiento. Estos objetivos se han alcanzado mediante la combinación de estudios de laboratorio y trabajo de campo. Por un lado, se realizaron diferentes experimentos bajo condiciones estables de temperatura y salinidad que dieron información sobre la disolución potencial del fuel del Prestige en agua marina. Además, dos campañas oceanográficas se llevaros a cabo en marzo y octubre del 2006 cerca de los pecios y las zonas adyacentes, con el objetivo de recoger agua marina. Se determinaron hidrocarburos en la materia sólida en suspensión y la fase disuelta del agua en la columna de agua de las tres estaciones. Una se encontraba encima de los pecios del Prestige mientras que las otras dos se localizaron a 73 millas náuticas, una al norte y la otra al sur de este punto. En marzo del 2006, en la zona del hundimiento y en las otras dos estaciones, las concentraciones de hidrocarburos de origen petrogénico estaban dentro el rango los niveles descritos en la literatura para áreas similares, mientras que los niveles en octubre del mismo año era superiores. Las concentraciones de hidrocarburos poliaromáticos encontrados en la fase disuelta eran, tanto en marzo como en octubre, mucho mayores que los niveles de referencia establecidos para la zona. La huella química de los hidrocarburos en octubre del 2006 indicó que los pecios del Prestige habían estado liberando fuel oil durante varios años después del accidente. Sin embargo, a pesar de la amplia presencia de hidrocarburos provenientes del petróleo en la columna de agua de las tres estaciones, no se puede afirmar que el Prestige constituía la fuente más importante de contaminación en le área, ya que los hidrocarburos parecían provenir de múltiples orígenes. De hecho, varias masas de agua presentan contenidos distintivos de hidrocarburos en la fase disuelta y material particulado. El estudio realizado se puede entender como un ejemplo del potencial de un pecio hundido en el Noratlántico profundo como fuente de contaminación. Aunque cada pecio representa un caso único, el conocimiento obtenido sobre la distribución espacial y temporal de los hidrocarburos después del accidente del Prestige se puede utilizar en futuros vertidos. / There is an apparent shortage of studies on the distribution and fate of oil hydrocarbons in open ocean waters. Nevertheless, given the increasing exploitation of oilfields in the high seas, and the intensification of maritime traffic, in the last decades, oil pollution of the marine environment beyond the continental platforms is increasing. In addition, new sources of pollution are being recognized. Thus, in recent years it has been noted that the high number of sunken vessels scattered in the oceans sea floor are potentially a present and future source of oil spills. In this thesis, the accident of the Prestige tanker in 2002 off the Galician coast is investigated as a case study of a deep sea spill in open ocean waters, since around 43,000 tonnes of heavy fuel oil were spilled after the vessel broke in two and sank. In addition, the area near the Galician Bank, where the Prestige wrecks are located, is hydrodynamically complex. The water column is comprised by five main water masses from different origins and physico-chemical properties, which may contribute to actively spread the oil released from the Prestige in different and distinct ways. In this context, the main aim of this study has been to determine the importance of the Prestige shipwrecks as a source of oil pollution in the waters near the Galician Bank several years after the accident took place and to investigate the role of the water masses in the sinking area in the transport and distribution of hydrocarbons. These objectives have been tackled by a combination of laboratory and field studies. First of all, several sets of experiments were carried out under controlled temperature and salinity conditions which provided information about the potential dissolution of the Prestige fuel oil in seawater. In addition, two oceanographic cruises were undertaken in March and October 2006, near the wrecks location and surrounding areas, to collect seawater samples. Hydrocarbons were determined in the suspended particulate matter (SPM) and dissolved phase (DP) in the water column of three stations. One was located above the Prestige wrecks, and the other two 73 nautical miles north and south of the Prestige incident area.Hydrocarbons concentrations from petrogenic sources in the SPM above the wreck and surrounding areas in March 2006 were within the range of abundances previously reported for similar areas, but much higher in October 2006. The concentrations of polycyclic aromatic hydrocarbons found in the DP were, both in March and October 2006, well above any expected background levels. The chemical fingerprint of the hydrocarbons indicated that in October 2006 the oil at the Prestige station originated from the wrecks. This, together with the unusually high relative concentration of hydrocarbons in the DP at the Prestige station in March 2006, indicates that the Prestige wrecks had been releasing oil for several years after the accident. However, despite the widespread occurrence of oil hydrocarbons in the three stations and throughout their water columns, it could not be concluded that the Prestige was the main source of pollution in the area near the Galician bank, which most likely has multiple origins. In fact, different water masses contain distinct contents of hydrocarbons in the SPM and the DP, which in some instances may have remote sources. The study conducted can be viewed as an example of the potential of a sunken wreck in the deep North Atlantic as a source of pollution. Although each potentially polluting shipwreck represents a singular case, knowledge obtained about the temporal and spatial distribution of hydrocarbons after the accident of the Prestige could be applied to deal with other deep spills in the future.
6

Integrating hydrodynamic and oil spill trajectory models for nowcasts/forecasts of Texas bays

Rosenzweig, Itay 03 October 2011 (has links)
A new method for automatically integrating the results of hydrodynamic models of currents in Texas bays with the National Oceanic and Atmospheric Administration’s (NOAA) in house oil spill trajectory model, the General NOAA Operational Modeling Environment (GNOME), is presented. Oil spill trajectories are predicted by inputting wind and water current forces on an initial spill in a dedicated spill trajectory model. These currents can be field measured, but in most real and meaningful cases, the current field is too spatially complex to measure with any accuracy. Instead, current fields are simulated by hydrodynamic models, whose results must then be coupled with a dedicated spill trajectory model. The newly developed automated approach based on Python scripting eliminates the present labor-intensive practice of manually coupling outputs and inputs of the separate models, which requires expert interpretation and modification of data formats and setup conditions for different models. The integrated system is demonstrated by coupling GNOME independently with TXBLEND – a 2D depth-averaged model which is currently used by the Texas Water Development Board, and SELFE – a newer 3D hydrodynamic model with turbulent wind mixing. A hypothetical spill in Galveston Bay is simulated under different conditions using both models, and a brief qualitative comparison of the results is used to raise questions that may be addressed in future work using the automated coupling system to determine the minimum modeling requirements for an advanced oil spill nowcast/forecast platform in Texas bays. / text
7

The Investigation of Mysterious Marine Oil Spills on the West Coast of Canada

Szeto, Andrew 03 August 2012 (has links)
The Government of Canada’s National Aerial Surveillance Program (NASP) is responsible for the monitoring of ship based oil pollution in Canada’s three oceans. In many of these spills, the source of pollution is unknown as there are often no vessels found in the vicinity at the time of detection. In this work, the oil spills found in 2010 on the West Coast of Canada, alongside the collated vessel traffic data captured by the Canadian Coast Guard are investigated to determine the vessels most likely responsible for these spills. In terms of tools and techniques applied, oil spills are firstly hindcasted using the General NOAA Operational Modeling Environment (GNOME) to determine the location of their source. ArcGIS is used to geospatially reference and combine various data sets, and lastly the Analytical Hierarchy Process (AHP) is used to rank possible polluters found in the area of the spill.
8

Fingerprinting simulated marine oil spills with gasoline-range compound specific isotope correlation

Kory, Michael David 01 May 2012 (has links)
Environmental liability cases involving spilled or released petroleum products into ocean ecosystems require oil identification techniques that are unambiguous and conclusive, even in situations where oils have been subjected to secondary environmental processes, such as, evaporation and dissolution. The ability and functionality of the Compound Specific Isotope Correlation (CSIC) technique is tested to determine its reliability to characterize released petroleum using the carbon isotope ratios (13C/12C) of the individual gasoline-range compounds (C5-C9). In particular, this thesis studies the potential of CSIC as a robust diagnostic tool, to identify and correlate marine releases of oil with their sources, especially those having undergone evaporative weathering. Three crude oils (Alberta Sweet Mixed Blend, Lacula and Louisiana) added to synthetic seawater were exposed to mechanically simulated wave energy and controlled evaporative weathering at 10 oC. Time-series sampling of the gasoline-range vapour fractions from the headspace employed Solid Phase Micro Extraction (SPME). SPME-Continuous Flow-Isotope Ratio Mass Spectrometry (SPME-CF-IRMS) determined the molecular abundances and stable carbon isotope ratios (δ13C) of the gasoline-range compounds of the original and weathered oils. Evaporation rates over the maximum 20 hour period varied for the 3 study oils. Most (74%) of the individual compounds measured in the oils display a δ13C enrichment with progressive evaporation with approximately half of the compounds in all 3 oils showing fractionation of the carbon isotopes ≤ 0.5‰ within measurement precision. The magnitude of carbon isotope shift observed in compounds pre-vs. post-weathering ranges from 0 to 2.8 ±0.6‰. There is no clear relationship identified between the degree of 13C enrichment in the oils and groupings such as chemical class, structure or carbon number. The overall weighted average 13C enrichment for all compounds in the 3 oils is approximately 1‰. Toluene was the only compound consistently exhibiting comparatively high 13C enrichment (1.6‰, 1.8‰ and 2.8‰) in all 3 oils after evaporative weathering. Hierarchical Cluster Analysis (HCA) treatment of the CSIC data set can reliably discriminate between the 3 oils despite evaporative weathering and δ13C changes. HCA is also able to unambiguously relate the three weathered oils back to their respective original unweathered oil. Diagnostic shifts in δ13C of individual compounds in an oil may potentially be used to trace weathered oils back to the source, and possibly give a estimation of time since release. However the typically rapid rate of evaporation for the gasoline-range fractions limits the time that an oil can be successfully identified by CSIC. / Graduate
9

Evaluation of the Impact of the Deepwater Horizon Oil Spill and Hurricanes on Wildfires in Southeast Louisiana

Carley, Richard 11 May 2013 (has links)
Remotely sensed MODIS fire detections were used to examine wildfire variability from 2003-2011 in southeast Louisiana, and to determine if the Deepwater Horizon oil spill and hurricanes may have impacted fire frequency and intensity. Despite low wildfire detection rates, around 60% for fires at least 1 km2 or greater, the MODIS fire product provided a consistent and reliable source of wildfire data. As a result of Hurricane Katrina, wildfire detection frequencies doubled their average numbers during the fall of 2005 in inland areas and during the spring of 2006 in inland and coastal marsh areas. Strangely enough, the oil spill may have contributed to lower fire frequencies in the summer of 2010 and spring of 2011 inland. Neither hurricane Katrina nor the oil spill were found to have an effect on fire intensity, and the spatial distribution of wildfires remained relatively constant over the study area after both disasters.
10

The impact of the 1989 Exxon Valdez oil spill on phytoplankton as seen through the dinoflagellate cyst record

Genest, Maximilien 28 September 2018 (has links)
Our knowledge of how oil spills affect coastal environments is severely limited by the shortage of research that addresses the impact of these events on phytoplankton, the single most important group of organisms in the marine ecosystem. This scarcity of knowledge is mainly attributed to the absence of baseline data, preventing the comparison of pre- and post-spill populations. This unique study aims to identify how dinoflagellates and diatoms, the two major groups of phytoplankton in coastal marine environments, have been affected by the 1989 Exxon Valdez oil spill in Prince William Sound (PWS), Alaska. To do this, sedimentary records of dinoflagellate cysts, produced during a dinoflagellate's life cycle and preserved in the sediment, and biogenic silica, a proxy for diatom abundance, were analyzed prior to, during and after the oil spill. The analysis of two well-dated cores in PWS reveals marked increases during the oil spill in the concentrations of total cysts of the species Operculodinium centrocarpum sensu Wall and Dale, (1966) and Dubridinium spp. Total cyst concentrations doubled in core P-10 from 362 to 749 per g, while in core P-12 the increase was from 1175 to 1771 cysts g-1. During this peak in cyst concentrations, total concentrations were 3 and 2 standard deviations greater than the mean in cores P-10 and P-12, respectively. Dubridinium spp. showed a five and sevenfold increase in concentrations in cores P-10 (4 to 20 cysts g-1) and P-12 (16 to 110 cysts g-1), respectively, while O. centrocarpum sensu Wall and Dale, (1966) doubled in concentrations in the two cores (P-10: 117 to 276 cysts g-1; P-12: 268 to 495 cysts g-1). Biogenic silica values did not show significant changes throughout the cores, with values varying between 8% and 9% in core P-10 and 9.0% to 10.9% in core P-12. These changes lie within or very close to the standard deviation of the analyzed standards, suggesting that much of the changes could be analytical noise. The dinoflagellate cyst signals seen in this study are comparable to those seen as a result of nutrient enrichment in estuarine systems, suggesting that the 1989 Exxon Valdez oil spill and its remediation had a stimulatory effect on some taxa of cyst- producing dinoflagellates. This impact appears to be short-lived, with cyst concentrations returning to pre-spill levels within two years of the event. The lack of change in diatom abundance, on the other hand, suggest that diatom abundance remained relatively constant during the entirety of the sample period. / Graduate / 2020-07-10

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