• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 42
  • 22
  • 7
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 106
  • 106
  • 106
  • 106
  • 20
  • 20
  • 17
  • 15
  • 13
  • 12
  • 11
  • 11
  • 11
  • 9
  • 9
  • 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.
31

Basin-scale spatiotemporal analysis of hydrologic floodplain connectivity

McCann, David Michael 30 May 2014 (has links)
Floodplain inundation often provides water quality benefits by trapping sediment and biogeochemically transforming other pollutants. Hydrologic floodplain connectivity is a measure of water exchanges and interactions between the main channel and the floodplain via surface (inundation) and subsurface (groundwater) connections. Using an automated model combining GIS and numerical analysis software, this study examined floodplain inundation patterns and measured floodplain connectivity for the Mahantango Creek watershed (Pennsylvania, USA). Connectivity was quantified by developing a metric that included inundation area and duration. Long-term hydrographs at each reach in the watershed were developed via QPPQ (Flow-Percentile-Percentile-Flow) methodology using regional regression analysis to calculate the ungauged flow duration curves (FDC). Inundation area (normalized to stream length) was found to increase with drainage area, suggesting larger streams have more area available for biogeochemical activity. Annual connectivity increased with drainage area, suggesting larger streams, having higher connectivity, should be the focus of individual reach restoration projects due to higher potential for water quality benefits. Across the watershed as a whole, however, the total annual connectivity across first order streams was greater than higher order streams, suggesting the collection of small streams in a watershed may have a stronger effect on outlet water quality. Connectivity was consistently higher during the non-growing season, which was attributed to higher flows. Despite higher connectivity during the non-growing season, increased floodplain biological activity may be negated by low temperatures, reducing microbial activity. Correlations between land use and connectivity were also found, emphasizing dynamics between flow, channel morphology, and floodplain inundation. / Master of Science
32

Combining Quantitative Eye-Tracking and GIS Techniques With Qualitative Research Methods to Evaluate the Effectiveness of 2D and Static, 3D Karst Visualizations: Seeing Through the Complexities of Karst Environments

Tyrie, Elizabeth Katharyn 01 May 2014 (has links)
Karst environments are interconnected landscapes vulnerable to degradation. Many instances of anthropogenic karst disturbance are unintentional, and occur because of the public's lack of understanding or exposure to karst knowledge. When attempts are made to educate the general public about these landscapes, the concepts taught are often too abstract to be fully understood. Thus, karst educational pursuits must use only the most efficient and effective learning materials. A technique useful for assessing educational effectiveness of learning materials is eye-tracking, which allows scientists to quantitatively measure an individual's points of interest and eye movements when viewing a 2D or 3D visualization. Visualization developers use eye-tracking data to create graphics that hold the observer's attention and, thereby, enhance learning about a particular concept. This study aimed to assess and improve the educational effectiveness of 2D karst visualizations by combining eye-tracking techniques with Geographic Information Systems, knowledge assessments, and semi-structured interviews. The first phase of this study consisted of groups of 10 participants viewing 2D karst visualizations with one category of manipulated visual stimuli. The second phase consisted of groups of 10-15 participants viewing 2D karst visualizations that were created based on the results from the first phase. The results of this study highlighted both effective stimuli in karst visualizations and stimuli that hinder the educational effectiveness of visualizations.
33

The Role of Geographic Information Systems in Post-Disaster Neighborhood Recovery: Lessons from Hurricanes Katrina and Rita

Baldwin, Brian 14 May 2010 (has links)
Through partnerships and collaborations with universities, non-profits, local government, and private foundations, neighborhood associations and residents have been using Public Participation Geographic Information Systems (PPGIS) as a tool for neighborhood recovery in post-Katrina and Rita New Orleans. The landfall of Hurricanes Katrina and Rita along the Gulf Coast Region changed the way that Geographic Information Systems (GIS) are used for Emergency Management and Response, PPGIS, and community recovery. This research explores GIS and PPGIS best practices through an evaluation of New Orleans, LA case studies and seeks to present solutions for the development of a post-disaster PPGIS for community recovery.
34

O uso de geotecnologias na gestão agrícola: um estudo aplicado ao processo de inspeção na citricultura / The use of geotechnology in management in agriculture: a study applied to the process of inspection in citriculture

Monzane, Márcio Rodrigo de Gonçalves 18 August 2008 (has links)
A presente dissertação constitui-se num estudo de caso que versa acerca da utilização da tecnologia GIS (Geographic Information System) no processo de inspeção agrícola. A pesquisa teve o caráter exploratório com metodologia qualitativa, tendo como técnicas de pesquisa a revisão bibliográfica, a fim de identificar os conceitos atinentes ao tema, análise documental, entrevistas semi-estruturadas e observação de campo. O significativo e constante crescimento da citricultura paulista no cenário mundial do agronegócio reforça a necessidade de se criar mecanismos para controle e desenvolvimento da atividade. Dessa forma, o referido estudo apresenta a compreensão e análise da utilização de uma tecnologia baseada em sistema de informação geográfica (software livre), desenvolvido por um centro nacional de pesquisa agropecuária, aplicada ao processo de inspeção citrícola de um instituto de pesquisa em citros, localizado na cidade de Araraquara, no Estado de São Paulo. / This work is based on a study of case about the use of the GIS (Geographic Information System) at the process of agricultural inspection. The research was an exploration using the qualitative methodology based on the bibliography review in order to identify the concepts of the theme, documental analyses, semi structured interviews and environmental research. A constant fairly increasing of the paulista citriculture worldwide reinforces the necessity of the creation of a mechanism to control and develop the activity. This way, the mentioned study presents comprehension and analyses of the technology utilization based on a geographic information system (free software), developed by a national center of agropecure research, applied to the process of citric inspection in an institute of research in citric placed in Araraquara in São Paulo state, Brazil.
35

Modelagem socioambiental de resíduos sólidos em áreas urbanas degradadas : aplicação na Bacia Mãe d'Água, Viamão, RS / Socio-environmental modelling of solid waste in urban degraded areas: a case study of Mãe d’Água Watershed, city of Viamão, Rio Grande do Sul, Brazil

Ribeiro, Bárbara Maria Giaccom January 2017 (has links)
As cidades são consideradas as mais elevadas formas de organização social; são redes onde acontecem as conexões sociais – dentro de outras redes: sociais, espaciais e de infraestrutura –, que possibilitam que pessoas, coisas e informações interajam através do espaço urbano. Entretanto, também é no ambiente urbano que se deflagram as maiores ameaças à urbanidade e à salubridade dos remanescentes de ambiente natural. Sendo o sistema urbano considerado um sistema de sistemas integrados, um dano em uma fração de uma rede urbana, e em um único local, pode gerar consequências em uma extensa área geográfica e envolvendo diversas dimensões do sistema urbano, afetando diretamente a economia local e regional. Em áreas urbanas caracterizadas pela ocupação irregular, já com algum grau de consolidação, devido a fatores relacionados à ineficiência de infraestrutura urbana e de serviços e às condições socioeconômicas e culturais, os sistemas de drenagem urbana tornam-se correias de transporte de resíduos sólidos aos cursos d’água. A presença de resíduos na rede de drenagem, além dos muitos impactos ao meio ambiente natural e à saúde humana, compromete a eficiência desses sistemas, estando diretamente relacionadas a entupimentos, inundações, ondas de resíduos sólidos e perdas econômicas. Além disso, aumentam dos custos de limpeza na drenagem, bem como o subsídio financeiro, i.e., o custo não investido ou não internalizado, que o ambiente transfere para sociedade. Estudos e ações, em escala de bacia hidrográfica urbana, para identificação do ciclo de geração, transporte e disposição final dos resíduos sólidos são essenciais para se evitar ou minimizar as destinações indevidas de resíduos e, consequentemente, o comprometimento dos recursos hídricos. Esta pesquisa propõe e define o “Ciclo Lixológico” a partir da integração de variáveis relativas ao ambiente físico, às características socioeconômicas da população e às condições da infraestrutura urbana existente. Toma-se a bacia hidrográfica da barragem Mãe d’Água, localizada na divisa de Porto Alegre e Viamão (RS) como estudo de caso. São utilizados dados espacializados relativos a características do relevo, dos corpos d’água e do sistema de drenagem, da infraestrutura de acesso e circulação; bem como dados de uso e ocupação do solo; dados demográficos e socioeconômicos, e informações de cobertura e regularidade do serviço de coleta de resíduos. Com base nestas informações, é proposta a modelagem da geração e do transporte de resíduos sólidos no contexto da bacia hidrográfica. A verificação do modelo utiliza observações de campo e dados in situ de resíduos sólidos capturados por uma armadilha instalada no exutório de uma das drenagens principais da bacia. Adicionalmente à quantificação da carga no exutório, o modelo permite a espacialização de resultados relativos à dinâmica de transporte de resíduos nas vias de escoamento naturais e antrópicas, bem como à identificação de locais de acumulação, ainda que temporária, de resíduos sólidos. Este modelo mostra-se operacional e passível de reprodução em outras bacias hidrográficas urbanas, de modo a contribuir com as futuras gestões de recursos hídricos e de resíduos sólidos, orientando o planejamento e a implementação de intervenções a curto e longo prazo. / Cities are the highest level of social organization, they are the networks where social connections are made. Within the city there are social, spatial, and infrastructural sub networks, which enable the interaction between people and things in the urban space. In the same space lie the biggest threatens to the urbanity and salubrity of the natural environment reminiscent. The urban system is a composition of integrated sub systems, therefore any damage to one fraction of this system may have a knock-on effect on a large geographic area and across multiple dimensions of the urban system; which can negatively affect the local and regional economy. Particularly in informal settlements, the inefficiency of the urban services and infrastructure together with socioeconomic and cultural conditions turn the urban drainage systems into routes of solid waste to rivers and water bodies. The existence of solid waste in urban drainage systems compromises the efficiency of the system and it is linked to clogging, floods, litter waves and economic losses. In addition, it also poses risk to human health, environment and increases the maintenance and social cost of the drainage system. For this reason, it is essential to develop studies and action plans, at watershed scale, to identify and describe the cycle of genesis, transportation and final disposition of solid waste. These studies can help minimizing the inappropriate discard of solid waste and potential damage to the freshwater resources. This research proposes and defines the “Wastelogical Cycle” through the integration of variables related to physical environment, socioeconomic characteristics, and quality of the urban infrastructure. The study is applied to Mãe d’Água dam watershed at Viamão city, Porto Alegre Metropolitan Region, Rio Grande do Sul state, Brazil. This study incorporates spatial data on the local geomorphology, hydrology, urban drainage system, access and circulation infrastructure, land cover, land use, demography, socioeconomic characteristics and information on the coverage and frequency of the solid waste collection service. Based on these data we modeled the genesis and transportation of solid waste within the watershed; the quality of the model was assessed via field observations and in situ data on solid waste collected by a trap at the estuary of one of the main drainage in the watershed. In addition to the quantification of the solid waste charge in the river mouth, the model allows spatial visualization of the dynamics of solid waste transportation at natural and anthropic water flow networks and the identification of hotpots for solid waste accumulation. The model is operational and reproducible for other urban watersheds, it has potential to contribute to the management of solid waste and hydrological resources in the future and may be used as a tool to direct and plan interventions in the short and long term.
36

Klamydiainfektioner i Sverige  : Kan en geografisk analys förklara det rumsliga mönstret?

Anyango, Carren January 2009 (has links)
<p>Chlamydia is a sexually transmitted infection. The infection rates have increased in the last decade. During 2008 the trend rates declined in all counties and regions in Sweden. Chlamydia infections have a geographical spatial pattern differences. This is seen from the national surveillance data report from the Swedish Institute for infectious disease control (SMI). The overall aim with the study is to conduct a geographical analysis of Chlamydia infections and explain the differences in the spatial pattern. The study is limited to the counties and a region that have been using Becton Dickinson laboratorial analysis methods. The study is based on statistics on Chlamydia infections incidence rates, from the SMI. The statistics did raise questions regarding the spatial patterns differences. Therefore some of the chosen counties and region were contacted through both telephone and email. Further information search was conducted on internet sites for some of the government authorities: The National Board of Health and Welfare, Swedish National Institute of Public Health etc. The mentioned authorities along with the SMI, play important roles in the area of sexually transmitted infections (STI).</p><p>Geographical spatial pattern differences of Chlamydia in the chosen counties and region can be explained on the basis of several factors. Statistics have been influenced by the fact that individuals have tested themselves in other areas/locations and not the locations where they have their permanent addresses (home areas). The quantities of taken samples and the effectiveness regarding the processes taken to reduce Chlamydia infections have led to detection of several cases and control of further infections. The public has more place access and opportunities of carrying out the tests (both in the region, the counties and through internet). The possibility to conduct detailed geographical studies has been limited because of the missing data at the municipality level. However, the study has raised questions that need further analysis. The previous research of Chlamydia infections has shown that other countries for example USA have succeeded in conducting detailed research studies of Chlamydia infections by using  geographic information systems (GIS) methods. Are there possibilities to conduct such research in Sweden with the current Swedish statistics on Chlamydia infections?</p><p> </p> / <p>Klamydia är en sexuell överförbar infektion. Klamydiainfektioner har under det senaste decenniet ökat på nytt i Sverige. År 2008 skedde en trendminskning i alla landsting och regioner. Utgångspunkten är att det finns mycket kunskap i samhället om klamydia och skyddsåtgärder för sjukdomen. Geografiska skillnader vad gäller spridning av klamydiainfektioner förekommer, vilket framgår av statistik från alla 21 landsting/regioner iSverige. Det övergripande syftet med studien är att göra en geografisk analys av klamydiainfektioner och ge en förklaring till förekommande skillnader av det rumsliga mönstret. Studien begränsar sig till landsting och regioner som använt sig av Becton Dickinsons testmetod och har utgått ifrån statistik från Smittskyddsinstitutet (SMI). Därefter har de berörda landstingen och regionerna kontaktats via både mail och telefon. Vidare informationssökning har skett hos de olika aktörerna inom klamydiaområdet såsom socialstyrelsen, statens folkhälsoinstitut osv.</p><p>Klamydiainfektioner har utvecklats i olika takt i de valda landstingen/regionen genom åren. Det rumsliga mönstret kan förklaras utifrån flera faktorer. Statistik påverkas av att individer testar sig på andra orter än där de är mantalsskrivna (hemkommuner). Antal tagna provmängder och effektivitet vad gäller handläggning av klamydiainfektioner leder tillupptäckt av flera fall och bromsar utvecklingen. Även tillgänglighet till platser för testninghar ökat i vissa län.</p><p>Möjlighet att genomföra en grundlig geografisk analys begränsas på grund av avsaknad avdata på kommunnivån. Däremot har studien lett till frågor som man bör söka svar på. Tidigare forskning har visat att andra länder exempelvis USA har lyckats genomföradetaljerade studier av klamydiainfektioner med hjälp av geografiskt informationssystem(GIS). Finns möjligheter att genomföra sådana klamydiastudier i Sverige med nuvarandesvensk data?</p>
37

Klamydiainfektioner i Sverige  : Kan en geografisk analys förklara det rumsliga mönstret?

Anyango, Carren January 2009 (has links)
Chlamydia is a sexually transmitted infection. The infection rates have increased in the last decade. During 2008 the trend rates declined in all counties and regions in Sweden. Chlamydia infections have a geographical spatial pattern differences. This is seen from the national surveillance data report from the Swedish Institute for infectious disease control (SMI). The overall aim with the study is to conduct a geographical analysis of Chlamydia infections and explain the differences in the spatial pattern. The study is limited to the counties and a region that have been using Becton Dickinson laboratorial analysis methods. The study is based on statistics on Chlamydia infections incidence rates, from the SMI. The statistics did raise questions regarding the spatial patterns differences. Therefore some of the chosen counties and region were contacted through both telephone and email. Further information search was conducted on internet sites for some of the government authorities: The National Board of Health and Welfare, Swedish National Institute of Public Health etc. The mentioned authorities along with the SMI, play important roles in the area of sexually transmitted infections (STI). Geographical spatial pattern differences of Chlamydia in the chosen counties and region can be explained on the basis of several factors. Statistics have been influenced by the fact that individuals have tested themselves in other areas/locations and not the locations where they have their permanent addresses (home areas). The quantities of taken samples and the effectiveness regarding the processes taken to reduce Chlamydia infections have led to detection of several cases and control of further infections. The public has more place access and opportunities of carrying out the tests (both in the region, the counties and through internet). The possibility to conduct detailed geographical studies has been limited because of the missing data at the municipality level. However, the study has raised questions that need further analysis. The previous research of Chlamydia infections has shown that other countries for example USA have succeeded in conducting detailed research studies of Chlamydia infections by using  geographic information systems (GIS) methods. Are there possibilities to conduct such research in Sweden with the current Swedish statistics on Chlamydia infections? / Klamydia är en sexuell överförbar infektion. Klamydiainfektioner har under det senaste decenniet ökat på nytt i Sverige. År 2008 skedde en trendminskning i alla landsting och regioner. Utgångspunkten är att det finns mycket kunskap i samhället om klamydia och skyddsåtgärder för sjukdomen. Geografiska skillnader vad gäller spridning av klamydiainfektioner förekommer, vilket framgår av statistik från alla 21 landsting/regioner iSverige. Det övergripande syftet med studien är att göra en geografisk analys av klamydiainfektioner och ge en förklaring till förekommande skillnader av det rumsliga mönstret. Studien begränsar sig till landsting och regioner som använt sig av Becton Dickinsons testmetod och har utgått ifrån statistik från Smittskyddsinstitutet (SMI). Därefter har de berörda landstingen och regionerna kontaktats via både mail och telefon. Vidare informationssökning har skett hos de olika aktörerna inom klamydiaområdet såsom socialstyrelsen, statens folkhälsoinstitut osv. Klamydiainfektioner har utvecklats i olika takt i de valda landstingen/regionen genom åren. Det rumsliga mönstret kan förklaras utifrån flera faktorer. Statistik påverkas av att individer testar sig på andra orter än där de är mantalsskrivna (hemkommuner). Antal tagna provmängder och effektivitet vad gäller handläggning av klamydiainfektioner leder tillupptäckt av flera fall och bromsar utvecklingen. Även tillgänglighet till platser för testninghar ökat i vissa län. Möjlighet att genomföra en grundlig geografisk analys begränsas på grund av avsaknad avdata på kommunnivån. Däremot har studien lett till frågor som man bör söka svar på. Tidigare forskning har visat att andra länder exempelvis USA har lyckats genomföradetaljerade studier av klamydiainfektioner med hjälp av geografiskt informationssystem(GIS). Finns möjligheter att genomföra sådana klamydiastudier i Sverige med nuvarandesvensk data?
38

Lithic Technology and Obsidian Exchange Networks in Bronze Age Sardinia, Italy (ca. 1600-850 B.C.)

Freund, Kyle P. 01 April 2010 (has links)
The Sardinian Bronze Age (Nuragic period) and the factors which created and maintained an island-wide identity as seen through the presence of its distinctive nuraghi have received considerable attention; however the amount of research directly related to the stone tools of the era has been relatively limited despite the wealth of knowledge it is capable of yielding. This thesis hopes to contribute to Sardinian archaeology through the study of ancient technology, specifically obsidian lithic technology, by combining typological information with source data gleaned from the use of X-ray fluorescence spectrometry (XRF). These data are integrated with statistical analyses breaking down the spatial distribution of nuraghi across the island through the use of distance-based methods, including k-means and kernel density analyses, which create a more comprehensive understanding of the island-wide political and social structure. This research will test the hypothesis that changes in the acquisition of obsidian raw materials were coupled with corresponding changes in how the obsidian was used. The results provide precedence for future work in Sardinia and create a model for integrating two types of analyses, sourcing and typological. By combining these results, it is possible to investigate how obsidian influenced the ancient economy as well as assess its cultural significance for people of the past.
39

Μελέτη του Νομού Αχαΐας με χρήση Γεωγραφικών Συστημάτων Πληροφοριών (GIS)

Γκαμούρα, Κανέλλα 04 December 2014 (has links)
Αυτή η εργασία έχει ως στόχο την περιβαλλοντική αξιολόγηση των δήμων του Νομού Αχαΐας με τη χρήση του GIS και των Ψηφιακών Υψομετρικών Μοντέλων Εδάφους(Ψ.Υ.Μ.Ε ή DEM). Τα παραπάνω δεδομένα μπορούν να χρησιμοποιηθούν σε περιπτώσεις εφαρμογών όπως: 1.Για κατασκευή ψηφιακών τοπογραφικών χαρτών 2.Για παραγωγή χαρτών σκιασμένου αναγλύφου (shaped relief maps),υψομέτρων,κλίσεων και εκθέσεων 3.Για ομαδοποίηση και καταμέτρηση χαρακτηριστικών αντικειμένων κατά κλάσεις υψομέτρων,κλίσεων και εκθέσεων 4.Για διευκόλυνση υδρολογικών μελετών (υδρογραφικό δίκτυο,όρια λεκάνης απορροής,κ.ά.) Επιπλέον,στο φυσικό περιβάλλον η μορφολογία εδάφους και οι καλύψεις της Γης μπορούν να βοηθήσουν στο σχεδιασμό(κόστος και τρόπος ανάπτυξης)ενός δικτύου κινητής ή σταθερής ασύρματης τηλεφωνίας αφού η διάδοση και η εμβέλεια του σήματος επηρεάζονται από αυτό. Στόχος της εργασίας αυτής είναι να ταξινομηθούν οι δήμοι του Ν.Αχαΐας βάση μορφολογικών παραμέτρων,να βρεθούν οι καλύψεις Γης από δορυφορικές φωτογραφίες και η ορατότητα των κεραιών βάση του DEM. / This work aims at assesing the environmental evaluation of municipalities of Prefecture Achaia with the use of GIS and Digital Hypsometric Models of Territory(DEM). The previous data can be used in cases of applications as: 1.For the manufacture of digital topographic maps 2.For the production of maps of shaded bas-relief(shaped relief maps),altitudes,bents and reports 3.For the regrouping and measurement of characteristic objects at age-groups of altitudes,bents and reports 4.For the facilitation of hydrologic studies (hydrographical network,limits of run-off plane,etc) Moreover,in the natural environment the morphology of soil and the covers of Earth can help in the planning(cost and way of growth)of a networkmobile or constant wireless telephony after the distribution and the scope of signal are influenced by this. The target of this work is to categorize the municipalities of Prefecture of Achaia base on morphological parameters,to find the covers of Earth from satelite photographs and the visibility of aerials base on DEM.
40

A Geographic Information System (GIS) Analysis of Cancer Clinical Trial Locations in the State of Georgia by Major Cancer Type

Parker, Shaunta Shanell 10 July 2008 (has links)
Improving cancer care through clinical research is a major public health issue. However, in Georgia, the exact number of cancer clinical trials is unknown, indicating the need for baseline data regarding cancer clinical trial locations and cancer burden. This study provides the first statewide analysis of cancer clinical trial locations using Geographic Information Systems (GIS). This study examines cancer clinical trial locations by county, according to incidence rates, racial patterns and mortality rates of the four major cancer types: breast, colorectal, lung, and prostate. Findings from this study suggest that metro-Atlanta counties have higher densities of cancer clinical trials. This study also found that there were little or no cancer clinical trials available in counties with the highest rates of overall incidence, African American incidence and overall mortality. This research demonstrates the need to increase availability of cancer clinical trials in counties with the highest cancer burden.

Page generated in 0.151 seconds