River ice is an important component of the traditional way of life for the communities along the Slave River both culturally and economically. During the winter, a stable ice cover provides local residents with safe access to their traditional hunting, trapping, and fishing grounds along the river. Periodic spring ice breakup flooding is required to maintain the ecological balance along the Slave River Delta. Recently, however, local observations have indicated changes in ice cover characteristics (e.g. air pocket formation, double layer ice, ice cover flooding) during the winter, which increase the risks of travelling on the ice. Also prolongs dry periods during the spring are leading to rapid growth of invasive vegetation that reduces the lake and channel areas of the Delta. Although some attempts have been made to understand the patterns of spring flood frequency in the Delta, very little is known about the Slave River’s ice cover characteristics and behaviour. Remote sensing techniques and field surveys were used in this study to understand the ice cover progression and to examine ice cover characteristics along the river during the winters of 2013-2014 and 2014-2015. RADARSAT-2 satellite imagery captured the changes in the ice cover and identified different types of ice during the winter seasons at two primary study sites – downstream of Fort Smith and the Slave River Delta. The mechanism of ice cover growth, with the formation of air pockets and layers underneath the ice cover was investigated. Steeper channels and several open water sections appear to be contributing to significant amounts of air entrainment into the water in winter. Changes in the hydraulic characteristics due to flow regulation and ice cover progression can also change the quantity and distribution of air pockets along the river ice cover. Additionally, the impact of flow fluctuations on the ice cover (e.g. ice cover flooding) was also observed. Increases in discharge cause the ice cover to crack or dislodge from the river banks, leading to water seeping onto the ice and flooding it, which has implications for the muskrat and beaver populations. A geospatial model was developed to determine the spatial patterns of ice cover breakup along the river from Fort Fitzgerald to the delta. This model successfully identified the areas of breakup initiation and persistence of ice until the end of the breakup. MODIS satellite imagery was used to describe the temporal patterns and evolution of breakup events between the years 2008 and 2011. In addition to geomorphological influences, air temperature and flow conditions also have strong impacts on the spatial and temporal patterns of the ice cover breakup.

This research relates Hg levels in the Common Loon (Gavia immer) to a variety of physical factors. Constructed within the framework of a GIS system, this model analyzes the spatial relationships and the influence of physical land cover factors as a function of distance from the individual loon territories. Thiessan polygons were used to generate the territory for each loon. Buffering of the thiessan polygons was done to establish the boundaries of the individual distance classes and to gather information on the percentage of individual land cover classes within each distance class. Information on precipitation was also gathered. Results from the regression analysis (R2 = 57.3% at the 150m distance class) performed on the variables suggest that the proximity of certain land use types such as cropland, shrub land, and wetlands influence the rates at which Hg is available within an individual territory. Within the 150m and 300m buffers, crop land, shrub land, and wetland exhibited the strongest relationship with the Hg levels in the common loon, with cropland exhibiting a negative relationship suggesting that the proximity of cultivated lands plays a role in decreasing the amount of available Hg in a territory. / Master of Science

Recently, the number of human cases of La Crosse encephalitis (LACE), an illness caused by mosquito-borne La Crosse (LAC) virus, has increased in southwestern Virginia, resulting in a need for better understanding of the virus cycle and the biology of its vectors in the region. This project examined the spatial and temporal distributions of the primary vector of LAC virus, Ochlerotatus triseriatus, and a potential secondary vector, Aedes albopictus. Ovitrapping surveys were conducted in 1998 and 1999 to determine distributions and oviposition habitat preferences of the two species in southwestern Virginia. For virus assay, adult mosquitoes were collected at a tire dump and a human case site during 1998 and 1999, and ovitrap samples were taken from a human case site in 2000. In a separate study, a landcover map of Wise County was created by supervised classification of Landsat Enhanced Thematic Mapper imagery, and maps indicating posterior probabilities of high mosquito abundance were created by combining ovitrap survey-derived, landcover-based prior and conditional probabilities for high and low mosquito abundance using remote sensing techniques and Bayesian decision-making rules. Both Oc. triseriatus and Ae. albopictus were collected from all ovitrap sites surveyed in Wise, Scott, and Lee Counties during 1998. Numbers of Oc. triseriatus remained high from late June through late August, while Ae. albopictus numbers increased gradually through June and July, reaching a peak in late August and declining thereafter. Overall, Oc. triseriatus accounted for 90.1% of eggs collected during this period, and Ae. albopictus made up the remaining 9.9%. Abundance of the two species differed among the sites, and in Wise County, relative Ae. albopictus abundance was highest in sites with traps placed in open residential areas. Lowest numbers of both species were found in densely forested areas. Ovitrapping at a human LACE case site during 1998 and 1999 revealed that Aedes albopictus was well-established and overwintering in the area. An oviposition comparison between yard and adjacent forest at the Duncan Gap human LACE case site in 1999 showed that Ae. albopictus preferentially oviposited in the yard surrounding the home over adjacent forested areas, but Oc. triseriatus showed no preference. LAC virus was isolated from 1 larval and 1 adult collection of Oc. triseriatus females from the Duncan Gap human case site, indicating the occurrence of transovarial transmission at this site. The supervised landcover classification for Wise County yielded a landcover map with an overall accuracy of 98% based on comparison of output classification with user-defined ground truth data. Posterior probability maps for Oc. triseriatus and Ae. albopictus abundance reflected seasonal and spatial fluctuations in mosquito abundance with an accuracy of 55-79% for Oc. triseriatus (Kappa=0.00-0.53) and 70-94% for Ae. albopictus (Kappa=0.00-0.49) when model output was compared with results of an ovitrapping survey. Other accuracy measures were also considered, and suggestions were offered for improvement of the model. / Master of Science

During the late 19th and into the 20th Century, the Tisza River’s vast floodplain-wetland systems were largely disconnected by levees, facilitating "reclamation" for agriculture and resulting in an estimated loss of over 90% of historical wetlands. While levees have been successful in preventing catastrophic flooding for a century, Lower Tisza flood stages continue to rise partially due to aggradation and increased roughness on the confined floodplain. The decrease in the Tisza's current floodway carrying capacity has reduced the flood-protection level of the Tisza's aging levee system. Recently in Hungary, "Room for the River" policies have gained more prominence. For the first of three papers for this dissertation, I assessed eight potential floodplain-reconnection scenarios that would provide more room for the river between Csongrád, Hungary and the Hungary-Serbia border. A novel framework using hydrodynamic and geospatial modeling was used to perform planning-level evaluations of the tradeoffs between floodplain-reconnection scenarios and enhancement of the existing levee system. The scenarios evaluated include levee removal and levee setbacks to strategically reconnect historical wetlands while reducing flood levels. Scenario costs and human population impacts were also assessed. Impacts of reconnecting the Lower Tisza floodplain were compared to heightening levees, the prevailing strategy over the previous century. From a purely construction-cost perspective, heightening Lower Tisza levees is potentially the most cost-effective and politically expedient solution (i.e., impacts the least number of people). However, levee heightening does not solve the long-term problem of reduced flood conveyance, nor does it result in wetland reconnection or enhancement of other floodplain ecosystem services. The suite of reconnection options evaluated provides engineers, planners, and decision makers a framework from which they can further evaluate potential flood-risk reduction options. At least three of the eight reconnection scenarios (setting the western levee back, 1500-meter, and 2000-meter setbacks) along the Lower Tisza demonstrated that floodplain-wetland reconnection is possible while achieving the objectives of minimizing impacts on human populations and reducing flood heights. The Illinois River has a similar history to the Tisza. Levees were constructed, and wetlands were drained during the late 19th and early 20th Centuries. By the mid-1920’s, Illinois River levee systems became increasingly difficult for private landowners and the state to maintain as commodity prices fell and flood levels increased. However, the 1928 U.S. Flood Control act shifted a substantial portion of the burden of flood mitigation from local landowners to the federal government, preventing the dissolution of levee districts. While these levee systems have facilitated floodplain agricultural production and development for the last century, disconnecting the river from its floodplain has led to concerns about the negative impacts of levees on the physical and biological systems of the Illinois River Valley. Recent studies have emphasized approaches that would result in setting back or removing levees in order to naturalize portions of large river-floodplain systems, including the Illinois. The costs and benefits of such projects have shown potential restoration benefits may outweigh potential costs, but these studies have not demonstrated the specific levee districts which have the highest reconnection potential from an economic standpoint. The second paper for this dissertation used geospatial methods to fill this gap by assessing the National Commodity Crops Productivity Index (NCCPI) soil values and agricultural production and profit values for corn and soybeans in 32 individual levee districts along a 235-km segment of the Lower Illinois River. In general, soil productivity index values were lower for Illinois River levee districts compared to the county averages in which the districts are located. Over the five-year study period from 2010-2014, the total agricultural profits in the levee districts ranged from $18-61 million. Several levee districts have relatively low per hectare agricultural values when compared to wetland benefit studies, indicating these protected floodplain areas may be suitable for reconnection. For the third and final dissertation paper I used a novel hydrodynamic, geospatial, economic, and habitat suitability framework to assess the tradeoffs of strategically reconnecting the 125-km La Grange Segment (LGS) of the Lower Illinois River to its floodplain in order to decrease flood risk, improve floodplain habitats, and limit the costs of reconnection. Costs included building-associated losses, lost agricultural profits, and total levee removal and construction costs. Modeled scenarios demonstrated that while flood heights and environmental benefits are maximized through the most aggressive levee setbacks and removals, these scenarios also have the highest economic costs. However, the tradeoff of implementing lower-cost scenarios is that there would be less flood-height reduction and less floodplain habitat available. Several levee districts had high potential for reconnection based on limiting potential damages as well as providing suitable floodplain habitat. To implement large-scale strategic floodplain reconnection along the LGS, opportunity costs ranged from $1.1-$4.3 billion. As such, payments for ecosystem services will likely be necessary to compensate landowners for building losses and decreased long-term agricultural production that result in an overall flood-reduction benefit, increased floodplain wetlands, and most-soil plant habitat.

Submitted by LUIZ HENRIQUE PEREIRA null (e_luizh@yahoo.com.br) on 2016-12-20T11:04:00Z No. of bitstreams: 1 pereira_lh_geo_RC.pdf: 6871364 bytes, checksum: 830de7380f478a93aeff860b974bc3ce (MD5) / Rejected by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: Incluir o número do processo de financiamento nos agradecimentos da dissertação/tese. Corrija esta informação e realize uma nova submissão com o arquivo correto. Agradecemos a compreensão. on 2016-12-22T10:30:31Z (GMT) / Submitted by LUIZ HENRIQUE PEREIRA (e_luizh@yahoo.com.br) on 2016-12-22T10:46:39Z No. of bitstreams: 1 pereira_lh_dr_rcla.pdf: 6574636 bytes, checksum: c3702d008829fade5dc14e767d174030 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-12-22T12:04:12Z (GMT) No. of bitstreams: 1 pereira_lh_dr_rcla.pdf: 6574636 bytes, checksum: c3702d008829fade5dc14e767d174030 (MD5) / Made available in DSpace on 2016-12-22T12:04:12Z (GMT). No. of bitstreams: 1 pereira_lh_dr_rcla.pdf: 6574636 bytes, checksum: c3702d008829fade5dc14e767d174030 (MD5) Previous issue date: 2016-10-28 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Atenuar incertezas nos resultados de modelos dinâmicos que estimam a produção de sedimento na vertente e o transporte do material no canal fluvial torna-se fundamental quando se considera a premência de políticas territoriais em minimizar o risco de sub ou super exploração dos recursos naturais, bem como indicar a disponibilidade de água em bacias hidrográficas. A aplicação de modelos de simulação de processos ambientais tem sido amplamente favorecida pelo avanço das geotecnologias, em especial dos Sistemas de Informações Geográficas, que viabilizam a extração, tratamento, análise e integração de dados geoespaciais. No entanto, observa-se que pouca atenção tem sido dada à análise e avaliação dos fatores responsáveis pela discrepância entre estimativas e observações. Diante o exposto, este trabalho apresentou como principal objetivo caracterizar a variabilidade espacial da incerteza propagada pela aplicação dos modelos hidrossedimentológicos EUPS, MEUPS e REUPS, e indicar sua correlação espacial com características geomorfométricas da área em análise. As atividades foram desenvolvidas com o escopo teórico da modelagem de sistemas ambientais, e baseadas em técnicas de geoprocessamento e sensoriamento remoto. Os resultados obtidos demonstram que a sensibilidade dos parâmetros é específica para cada tipo de bacia modelada, sendo os Fatores C, P os mais sensíveis para bacia do Monjolo Grande, e os Fatores C e LS os mais sensíveis para a bacia do ribeirão Jacutinga. As incertezas possuem maior expressividade nas áreas predominantemente de solos arenosos, e há correlação significativa do grau de incerteza dos resultados dos modelos com as características geomorfológicas, sobretudo em áreas de vertentes côncavas. / Lessening the uncertainties in the results from geospatial dynamic models, considering those that estimate the sediment production in the hillslope and the transportation of sediments over the river-channel, becomes essential when considering the current need to gather trustworthy quantitative information. In this sense, the contribution of hydro-sedimentological modeling is a significant part on the landscape planning phase, effectively composing the process of agricultural land management. The application of geospatial modeling has been widely benefited by the improvement on geotechnologies. However, it´s application has been applied indiscriminately from the procedures and methods for gathering entrance data. Differences in spatial scale of analysis, the characteristics of the geographical area of interest and the evaluation of the trustworthiness of the results are not taken into account. With these issues exposed this paper aimed to characterize the spatial variables and the uncertainties programed by the applications of the hydro-sedimentological models USLE, MUSLE e RUSLE. Indicating it´s spatial correlation with the geomorphometry characteristics of the analyzed areas it was possible to propose an objective criteria for the selection of the models based on the area´s geomorphological characteristics searching to minimize the statistical uncertainties thus offering measurements of trustworthiness in the final results. The activities were developed with the theoretical scope of environmental systems modeling and based on geoprocessing and remote sensing techniques. Results gathered show that the sensitivity of the parameters is specific to each type of watershed that was modeled, C and P factors being the most sensitives for Monjolo Grande river basin (sandy soil), and C and LS factors were the most sensitives for Jacutinga river basin (clay soil). The uncertainties are more prominent in the areas where the soil is predominantly sandy. There was a significant correlation between the level of uncertainty and the results from the models with geomorphological characteristic, especially in concave hillslope areas. / FAPESP: 2013/13885-0

This study compares suspended sediment and land use/land cover in the watershed of Weeks Bay, Alabama. Using Landsat thematic mapper imagery, potential high and low erosion sites were determined based on the increase in urban development form 2002 to 2005. In situ sediment sampling was used to test the hypothesis that the high erosion potential sites have larger amounts of suspended sediments. Additionally, sampling was performed along the Fish and Magnolia rivers to establish a background total suspended sediment level. The background study established an average total suspended sediment concentration of 18.71 mg/L for the Fish River and 17.47 mg/L for the Magnolia River, which are higher than previous studies. The results of the comparison between suspended sediments and land use/land cover proved to be more complex than expected due to variation in precipitation, to the 30 m satellite resolution, and to the criteria for classifying urban land use.

No description available.

Made available in DSpace on 2016-07-18T17:53:15Z (GMT). No. of bitstreams: 1 miriam ubida sales.pdf: 372296 bytes, checksum: f4ab27f8a6b466463d2c2ca5401a4ec3 (MD5) Previous issue date: 2015-03-26 / To evaluate the presence of pathogenic and apathogenic strains of Listeria spp in urban parks and squares in the city of Presidente Prudente, 117 soil samples from 57 different georeferenced locations were evaluated for pH and inoculated in Fraser Broth for selective enrichment of Listeria spp. After incubation at 30° C for 7 to 21 days, broth with evidence of growth were plated on ALOA chromogenic agar. Bacterial colonies compatible with the Listeria were classified by morphotinctorial and biochemical criteria and evaluated for antimicrobial susceptibility by disk diffusion method. Listeria was isolated in 37 squares / parks (64.9%) and 57 of 117 samples (47.8%) of soil, of which 5 were classified as L. monocytogenes and 2 as L. ivanovii. There was a predominance of acidic pH in the city soil (mean = 5.44). The average pH did not differ between positive and negative isolates samples with Listeria spp (p = 0.5523). Spatial modeling techniques revealed no link between points with positive isolates and variability of soil pH. The type of square / park (infant, sports, garden and rest) did not affect the percentage of isolation for Listeria spp. Sandy soils tended to have lower percentages of isolation than clay soils. The seven isolated pathogenic were resistant to four or more antibiotics, including ampicillin (3/7 = 42.9%) and sulfonamides (5/7 = 71.4%). Considering that no collection point received recent fertilization, we concluded that pathogenic and apathogenic Listeria species are dispersed in the soil of urban areas, even under unfavorable pH and the absence of organic fertilizer use. / Para avaliar a presença de linhagens patogênicas e apatogênicas de Listeria spp em parques e praças urbanos do município de Presidente Prudente, 117 amostras de solo de 57 diferentes locais georeferenciados, foram avaliadas quanto ao pH e inoculadas em caldo Fraser para enriquecimento seletivo de Listeria spp. Após incubação a 30ºC por sete a vinte e um dias, caldos com crescimento evidente foram plaqueados em ágar cromogênico ALOA. Colônias bacterianas compatíveis com o gênero Listeria foram classificadas por critérios morfotintoriais e bioquímicos e avaliadas quanto a sensibilidade microbiana pelo método de disco difusão. Listeria spp foi isolada de 37 praças/parques (64,9%) e de 56 das 117 amostras (47,8%) de solo, das quais cinco foram classificadas como L. monocytogenes e duas como L. ivanovii. Observou-se predomínio do pH ácido no solo do município (média=5,44). O pH médio não diferiu entre amostras com isolamentos positivos e negativos para Listeria spp (p=0,5523). Técnicas de modelagem espacial não revelaram relação entre pontos com isolamentos positivos e variabilidade do pH do solo. O tipo de praça/parque (infantil, esportivo, jardim e descanso) não influenciou nos percentuais de isolamento para Listeria spp. Solos arenosos tenderam a apresentar percentuais de isolamento inferiores aos solos argilosos. Os sete isolados patogênicos apresentaram resistência a quatro ou mais antimicrobianos, incluindo ampicilina (3/7=42,9%) e sulfonamidas (5/7=71,4%). Considerando-se que nenhum ponto de coleta recebeu adubação recente, conclui-se que espécies patogênicas e apatogênicas de Listeria estão dispersas no solo de aglomerados urbanos, mesmo sob pH desfavorável e a ausência do uso de adubo orgânico.

Der Einfluss des Menschen verändert die Erdoberfläche in gravierendem Maße. Die Anwendung von Landnutzungsmodellen ist etabliert, um derartige Prozesse zu analysieren und um Handlungsempfehlungen für Entscheidungsträger zu geben. Landnutzungsmodelle stehen unter dem Einfluss von Unsicherheiten, welche beim Interpretieren der Ergebnisse berücksichtigt werden müssen. Dennoch gibt es wenige Ansätze, die unterschiedliche Unsicherheitsquellen mit ihren Interdependenzen untersuchen und ihre Auswirkungen auf die projizierte Änderung der Landschaft analysieren. Aus diesem Grund ist das erste Ziel dieser Arbeit einen systematischen Ansatz zu entwickeln, der wesentliche Unsicherheitsquellen analysiert und ihre Fortentwicklung zur resultierenden Änderungskarte untersucht. Eine andere Herausforderung in der Landnutzungsmodellierung ist es, die Eignung von Projektionen abzuschätzen wenn keine Referenzdaten vorliegen. Bayes’sche Netze wurden als eine vielseitige Methode identifiziert, um das erste Ziel zu erreichen. Darüber hinaus wurden die Modellierungsschritte „Definition der Modellstruktur“, „Auswahl der Eingangsdaten“ und „Weiterverarbeitung der Daten“ als wesentliche Unsicherheitsquellen identifiziert. Um das zweite Ziel zu adressieren wurde eine Auswahl an Maßzahlen entwickelt. Diese quantifizieren Unsicherheit mit Hilfe einer projizierten Änderungskarte und ohne den Vergleich mit Referenzdaten. Mit diesen Maßzahlen ist es zusätzlich möglich zwischen quantitativer und räumlicher Unsicherheit zu unterscheiden. Vor allem in räumlichen Anwendungen wie der Landnutzungsmodellierung ist diese Möglichkeit wertvoll. Dennoch kann auch ein absolut sicheres Modell gleichzeitig ein falsches und nutzloses Modell sein. Deswegen wird ein Ansatz empfohlen, der die Beziehung zwischen Unsicherheit und Genauigkeit in bekannten Zeitschritten schätzt. Die entwickelten Ansätze geben wichtige Informationen um die Eignung von modellierten Entwicklungspfaden der Landnutzung zu verstehen. / Human influence has led to substantial changes to the Earth’s surface. Land change models are widely applied to analyze land change processes and to give recommendations for decision-making. Land change models are affected by uncertainties which have to be taken into account when interpreting their results. However, approaches which examine different sources of uncertainty with regard to their interdependencies and their influence on projected land change are rarely applied. The first objective of this thesis is therefore to develop a systematic approach which identifies major sources of uncertainty and the propagation to the resulting land change map. Another challenge in land change modeling is the estimation of the reliability of land change predictions when no reference data are available. Bayesian Belief Networks were identified as a useful technique to reach the first objective. Moreover, the modeling steps of “model structure definition”, “data selection” and “data preprocessing” were detected as relevant sources of uncertainty. To address the second research objective, a set of measures based on probabilities were developed. They quantify uncertainty by means of a single predicted land change map without using a reference map. It is additionally possible to differentiate uncertainty into its spatial and quantitative components by means of these measures. This is especially useful in spatial applications such as land change modeling. However, even a certain model can be wrong and therefore useless. Therefore, an approach is suggested which estimates the relationship between disagreement and uncertainty in known time steps to use this relationship in future time steps. The approaches give important information for understanding the reliability of modeled future development paths of land change.