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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

Changes in phenological time series in Estonia and central and eastern Europe 1951-1998 : relationships with air temperature and atmospheric circulation /

Aasa, Anto, January 2005 (has links) (PDF)
Thesis (doctoral)--University of Tartu, 2005. / Vita. Includes bibliographical references.
2

Consideration for the impact of climate change information on stated preferences /

Barak, Boaz. January 2006 (has links)
Thesis (Ph. D.)--University of Rhode Island, 2006. / Includes bibliographical references (leaves 269-279).
3

Climate effects on phytoplankton biomass and functional groups /

Markensten, Hampus, January 2005 (has links)
Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Felaktig titel på omslag och rygg: Climate effect on phytoplankton biomass and functional groups. Härtill 5 uppsatser.
4

ReDesign for a new energy paradigm /

Lewton, Alexander Tripp. January 2008 (has links) (PDF)
Thesis (M Arch)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Christopher Livingston. Includes bibliographical references (leaves 97-99).
5

Climate change and variability and their impacts on the yields of major food crops in Rwanda

Muhire, Innocent 02 July 2015 (has links)
PhD. (Environmental Management) / Climate change and variability has rapidly emerged as one of the most serious threats to sustainable development especially for developing African countries such as Rwanda. Since most of the agricultural activities in African countries are rain-fed, any adverse change in climate is likely to have a devastating effect on output and the livelihood of the majority of the population in the affected countries. Therefore, there should be continuous and regular preparedness to on-going climate variability. Climate change and variability derived information, are most likely to improve the agricultural outcomes when it is integrated into a framework for decision making to mitigate specific risks. It is in that regard, this research aims at analyzing climate change and variability and their impacts on the yields of major food crops in Rwanda. The raw climatic data (temperatures and precipitations) used in this study were obtained from the Rwandan Meteorological Center based in Kigali and Rwanda Environment Management Authority (REMA) while the agricultural records were collected from the National Institute of Statistics of Rwanda (NISR) and the Ministry of Agriculture and Animal Resources (MINAGRI). Length and completeness of records were the basic criteria used to select weather stations in order to have the most complete dataset. Five major crops, namely beans, cassava, Irish potatoes, maize, and sweet potatoes were selected for investigation because they are grown over large areas in most parts of the country during the two agricultural seasons i.e. season A (September-January) and season B (February-June). This research uses a number of statistical techniques in an attempt to quantify the magnitude and significance in temperature, rainfall, number of rainy days, aridity index and rainfall erosivity changes and variability taking place over Rwanda. The same techniques were applied in determining the magnitude and significance of inter-annual variations in food crop yields over Rwanda. A geographical information system (GIS) was used to present spatially the results on maps...
6

Enhancing livelihood strategies of rural communities prone to climate risk in the Caprivi Region of Namibia

Nyambe, Jacob Mulele January 2013 (has links)
Thesis (PhD. (Agricultural economics)) --University of Limpopo, 2013 / Declining rural livelihood and coping strategies in the Caprivi region have for some time been blamed on climate risk factors alone. Prominent climate risk factors are drought and floods. While the indignation of many speculators about the devastating effects of climate risk factors on annual harvests may be valid, the truth is that there are now new constraints on the livelihoods of rural households. Multi-stage cluster and stratified random sampling were used in identifying respondents. Data was collected by means of face-to-face interviews with a structured questionnaire that was applied on a sample of 253 respondents. The respondents resided in three constituencies, namely Kabbe, Katima Rural and Linyanti, which are classified as floodplains. With regards to the analytical framework, the thesis used descriptive statistics, factor analysis, a logistics regression model, as well as an unconstrained multivariate regression model. The objective of the thesis is to suggest mitigating strategic policy prescriptions that will enhance the livelihoods of rural communities in the Caprivi region. The results revealed that albeit agriculture is the main livelihood strategy, it is on a declining path in the context of livestock numbers (cattle, goats and chickens) and crop harvest (maize, millet and sorghum). Of the respondents, a substantial number (31%) of rural households are headed by people who are ≥ 56 years of age. Notwithstanding the damage caused to crop fields by other factors, the main causative factor to the poor harvest in 2007 was wild animals. The biannual harvesting approach has been abandoned for a single approach owing to climate risk factors and changes in the natural environment attributed to climate change and destruction of crop field by wild animals. The average annual rainfall at Katima Mulilo is 653 mm, but volatility in annual rainfall often results in drought or floods. Malaria, Human Immunodeficiency Virus and Acquired Immune Deficiency Syndrome are to blame for reduced availability of labour to maintain livelihood activities that sustain rural households. The results further show that five factor components make rural households eligible for receiving food aid. The first is the capacity to farm, the second is climate risk awareness, the third is household economic status, the fourth is past economic opportunities, and the last factor is household labour fitness. Salient to a rural farming household’s decision to farm are three variable, namely food cost, age of the head of the household and the value of food aid. Using income as a proxy to the de factor inadvertent climate risk occurrences and damage to crops by wild animals, pension in the hands of heads of rural households, the value of livestock owned by rural households and, the value of food aid provided to rural households proved to have a significant relationship with rural household income. In order to enhance rural livelihoods in the study area, the government and development partners should work towards establishing a repository for indigenous knowledge which rural communities have employed in the past. This knowledge should be improved on in order to use it in tackling related challenges in future. There is a need to invest more in agricultural infrastructure such as water-catchment facilities and irrigation infrastructure to assist communities to embark on irrigated vegetable farming in dry seasons; establish health facilities close to rural communities that are remote; address the lack of access to finance in the study area; and as an illustration of the lack of government projects in the study area, the green scheme should be rolled out in the area. The opening up of conservancies in areas where rural communities eke out their living from the agricultural livelihood strategy has caused unintended consequences for farming rural households. Thus the policy interface gap between the opening up of community conservancies and the agricultural policy affecting the agricultural livelihood strategy need to be addressed.
7

Riskbegreppets ogreppbarhet : En studie av riskbegreppets rörliga aspekter och dess påverkan på Karlstad kommuns hantering av översvämningsrisker. / The notion of risk and its intangible features : A study of the different perspectives of risk management and its impact on Karlstad Municipality’s management of flood-risks.

Persson, Jens January 2016 (has links)
The purpose of this essay is to provide a deeper understanding of how the notion of risk and its intangible features affects the spatial planning of Karlstad Municipality with focus on how central actors (Karlstad Municipality and Länsstyrelsen Värmland) are handling the notion of flood-risks. This is interesting to study especially when considering building new living areas on ground that is troubled with floods. What becomes interesting to study is how the view on risk-management differs among actors. The methods used for conducting this research are document analysis and interviews which hopefully will bring a deeper understanding of how the notion of risk is being treated differently depending of which actor is being studied. In this study, a case-study was made on a planning-process of a new residential area located on flood-prone area. The result shows that both actors studied are not willing to take any risks when it comes to prognoses of climate change. On the other hand, for Länsstyrelsen there was a small doubt towards building on these kinds of areas. The difference in the view of risk seems to lie in which understanding we have of what we know. Länsstyrelsen seems to be skeptical to the trust in knowledge and technology that Karlstad Municipality seems to have. That view could be involuntary though, especially because of the lack of residential apartments along with the market ideals of building close to water. The problem is that they are building on attractive but yet risky areas, and to reduce these risks a flood guard has been built. The situation becomes a paradox where they want to have the cake and still eat it. This dilemma is very expensive and at the same the solutions made are not 100 % safe regarding the uncertainty of climate change. This paradox implies that risks are being created which later have to be dealt with. The central actors deal with the situation in the best way through trusting the technology and the prognoses that are provided today. / Syftet med uppsatsen är att ge en djupare förståelse för hur riskbegreppets ogreppbarhet påverkar Karlstads samhällsplanering med fokus på hur centrala aktörer (Karlstad kommun och Länsstyrelsen Värmland) förhåller sig till översvämningsrisker. Detta är intressant att undersöka med tanke på att det byggs nya bostadsområden på mark som är översvämningsdrabbat. Det som då blir intressant att undersöka i en sådan här fråga är hur synen på risk skiljer sig olika centrala aktörer emellan. Metoderna som använts som försök för att besvara dessa frågor är dokumentanalyser som tillsammans med intervjuer förväntas ge en djupare förståelse för hur synen på risk kan se olika ut beroende på vilken aktör som studeras. I detta fall gjordes en fallstudie på en enskild planprocess tillhörande ett område som i skrivande stund planeras byggas i ett riskfyllt område. Resultatet visade att båda parterna inte är villiga att ta några som helst risker när det kommer till de prognoser vi har idag. För Länsstyrelsens del fanns dock en grundläggande skepsis mot dessa typer av byggnationer. Skillnaden i synen på risk verkar ligga i förhållandet till det vi vet. Länsstyrelsen visade sig vara skeptisk till den tillit på teknik och kunskap som Karlstad kommun verkar ha. Problemet är att det byggs på ett eftertraktat område som innebär tydliga risker och för att minska dessa risker byggs ett översvämningsskydd. På så sätt blir det ett dilemma som är väldigt kostsamt och som till 100 % kanske inte ens går att lösa med tanke på osäkerheten i klimatförändringarna. Denna paradox innebär alltså att man bygger sig till risker som sedan måste hanteras. Situationen är dock som den är idag vilket gör att de centrala aktörer som spelar en roll i denna nyexploatering helt enkelt måste göra det bästa av situationen och förlita sig på den teknik och de prognoser som finns idag.
8

Effect of pleistocene climatic changes on the evolutionary history of South African intertidal gastropods

Muteveri, Tinashe 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Historical vicariant processes due to glaciations, resulting from the large-scale environmental changes during the Pleistocene (0.012-2.6 million years ago, Mya), have had significant impacts on the geographic distribution of species, especially also in marine systems. The motivation for this study was to provide novel information that would enhance ongoing efforts to understand the patterns of biodiversity on the South African coast and to infer the abiotic processes that played a role in shaping the evolution of taxa confined to this region. The principal objective of this study was to explore the effect of Pleistocene climate changes on South Africa′s marine biodiversity using five intertidal gastropods (comprising four rocky shore species Turbo sarmaticus, Oxystele sinensis, Oxystele tigrina, Oxystele variegata, and one sandy shore species Bullia rhodostoma) as indicator species. Sequence data obtained from partial segments of the mitochondrial cytochrome oxidase c subunit 1 (COI), and the nuclear ribosomal DNA (encompassing part of 5.8S, second Internal Transcribed Spacer and part of 28S, hereinafter called ITS2; or comprising part of the first Internal Transcribed Spacer, 5.8S, second Internal Transcribed Spacer and part of 28S, hereinafter called ITS), were used as genetic markers to construct phylogeographic patterns and to investigate demographic histories of the taxa. Population structure was investigated using haplotype network analyses, pairwise ΦST statistics, analysis of molecular variance (AMOVA), isolation by distance analyses, Bayesian analysis of population structure (BAPS) and coalescent analysis of gene flow. Demographic history was analysed through Fu′s Fs tests, mismatch distributions, and Bayesian skyline plots. Demographic analyses suggest that all five intertidal gastropods studied experienced demographic expansions dating to the late Pleistocene. The sandy shore direct developer B. rhodostoma began expansion after the LGM (c. 15 kya) whereas for the four rocky shore broadcast spawners (T. sarmaticus, O. sinensis, O. tigrina, and O. variegata) the onset of expansion coincided with or preceded the LGM (c. 25, 60, 50, 40 kya, respectively). Consistent with recent range expansions and gene flow patterns, the population genetic structure in all species was characterised by shallow or a lack of population differentiation. Oxystele variegata was an exception as it showed a deep disjunction, of late Pleistocene origin, between individuals in the west coast Namaqua Bioregion and those in the south coast Agulhas Bioregion. These results provide strong evidence of the vital role that Pleistocene climatic changes and current regimes played in shaping the nature and distribution of biodiversity on the South African coast. In addition, gene flow in all species, except O. tigrina, was remarkably asymmetrical with the regions around Cape Infanta and Port Elizabeth acting as source populations. Considering the generally weak population genetic structure and gene flow patterns detected for most gastropod species studied here, it is recommended that T. sarmaticus, O. sinensis, O. tigrina and B. rhodostoma be managed as panmictic populations, and that the region encompassing Cape Infanta, and Port Elizabeth should be prioritised for conservation as it appears to harbour source populations. Oxystele variegata was the only species showing distinct population structure and in this instance, species specific conservation efforts should recognize this divergence by treating the two genetic assemblages as distinct management units. / AFRIKAANSE OPSOMMING: Historiese vikariante prosesse kan toegeskryf word aan glasiasie, en het tot gevolg gehad dat grootskaalse veranderinge in die omgewing plaasgevind het tydens die Pleistoseen (,012 - 2.6 miljoen jaar gelede, Mjg). Dit het 'n beduidende impak gehad op die geografiese verspreiding van spesies, veral ook in die mariene stelsels. Die motivering vir hierdie studie was om nuwe data te voorsien wat sal bydrae tot die voortgesette pogings om die patrone van biodiversiteit langs die Suid-Afrikaanse kus te verstaan. Dit sou ook help om die abiotiese prosesse af te lei wat 'n rol gespeel het in die evolusie van taksa wat in hierdie streek voorkom. Die hoofdoel van hierdie studie was om die effek van die Pleistoseen klimaatsveranderinge op Suid-Afrika se mariene biodiversiteit te bepaal deur gebruik te maak van vyf intergety slak spesies as indikatore (vier wat in rotsagtige gebiede voorkom: Turbo sarmaticus, Oxystele sinensis, Oxystele tigrina, Oxystele variegata en 'n sanderige strand spesies: Bullia rhodostoma). Volgorde data verkry vanaf gedeeltelike segmente van die mitochondriale sitochroom oksidase c subeenheid 1 (COI), en die kern ribosomale DNA (bestaande uit 'n deel van 5.8S, tweede interne getranskribeerde spasieërders en 'n deel van 28S), hierna genoem ITS2 is gebruik as genetiese merkers om filogeografiese patrone te dokumenteer en ook om die demografiese geskiedenis van die spesies te ondersoek. Bevolking struktuur is ondersoek deur gebruik te maak van haplotipe netwerk analise, paarsgewyse ΦST statistiek, analise van molekulêre variansie (AMOVA), isolasie deur afstand analise, Bayesiaanse analise van die bevolking struktuur (BAPS) en analise van gene vloei. Demografiese geskiedenis is ontleed deur Fu se Fs toetse, misparing verdelings, en Bayesiaanse luglyn kurwes. Demografiese ontleding dui daarop dat al vyf die intergety slakke wat ondersoek is demografiese uitbreidings ervaar het wat terugdateer tot die einde van die Pleistoseen. Die sanderige strand direkte ontwikkelaar, B. rhodostoma, het die uitbreiding begin na die LGM (c. 15 Kya), terwyl vir die vier rotsagtige kusbewoners wat eiers oor 'n uitgebreide gebiede versprei (T. sarmaticus, O. sinensis, O. tigrina, en O. variegata) het die aanvang van die bevolkings uitbreiding saamgeval met die laaste galsiasie of dit voorafgegaan (c. 25, 60, 50, 40 Kya, onderskeidelik). In ooreenstemming met die onlangse reeks bevolkings uitbreidings, is die bevolking genetiese struktuur in alle spesies gekenmerk deur weinig differensiasie. Oxystele variegata was 'n uitsondering en het 'n ontwrigting van laat Pleistoceen oorsprong getoon tussen individue langs die weskus Namaqua Biostreek en dié in die suid kus Agulhas biostreek. Hierdie resultate voorsien sterk bewyse van die belangrike rol wat die Pleistoseen klimaatsveranderinge gespeel het in die vorming en verspreiding van biodiversiteit langs die Suid-Afrikaanse kus. Daarbenewens, geen vloei in alle spesies, behalwe O. tigrina, was merkwaardig asimmetries. Kaap Infanta en Port Elizabeth verteenwoordig moontlik die bron bevolkings. Met inagneming van die geringe bevolking genetiese struktuur en geenvloei patrone wat waargeneem is vir die meeste slak spesies wat bestudeer is, word dit aanbeveel dat T. sarmaticus, O. sinensis, O. tigrina en B. rhodostoma bestuur word as 'n panmiktiese bevolking, en dat die streek wat Kaap Infanta en Port Elizabeth insluit geprioritiseer moet word vir bewaring. Oxystele variegata was die enigste spesie wat duidelike bevolking struktuur getoon het en in hierdie geval, moet spesie spesifieke bewaringspogings aangewend word.
9

Tracking Climate-Driven Changes in Neandertal Subsistence Behaviors and Prey Mobility Patterns

January 2012 (has links)
abstract: The ability of Neandertals to cope with the oscillating climate of the late Pleistocene and the extent to which these climate changes affected local Neandertal habitats remain unanswered anthropological topics of considerable scientific interest. Understanding the impact of climatic instability on Neandertals is critical for reconstructing the behaviors of our closest fossil relatives and possibly identifying factors that contributed to their extinction. My work aimed to test the hypotheses that 1) cold climates stressed Neandertal populations, and 2) that global climate changes affected local Neandertal habitats. An analysis of Neandertal butchering on Cervus elaphus, Rangifer tarandus, and Capreolus capreolus skeletal material deposited during global warm and cold phases from two French sites - Pech de l'Az&eacute; IV and Roc de Marsal - was conducted to assess the impact of climate change on butchering strategies and resource extraction. Results from a statistical analysis of surface modification on all marrow yielding long bones, including the 1st phalanx, demonstrated that specimens excavated from the cold levels at each cave have more cut marks (Wald &chi;2= 51.33, p= <0.001) and percussion marks (Wald &chi;2= 4.92, p= 0.02) than specimens from the warm levels after controlling for fragment size. These results support the hypothesis that Neandertals were nutritionally stressed during glacial cycles. The hypothesis that global climates affected local habitats was tested through radiogenic strontium isotopic reconstruction of large herbivore mobility patterns (e.g., Bison, Equus, Cervus and Rangifer), because it is known that in the northern hemisphere, mammals migrate less in warm, well-vegetated environments, but more in cold, open environments. Identifying isotopic variation in mammalian fossils enables mobility patterns to be inferred, providing an indication of whether environments at Pech de l'Az&eacute; IV and Roc de Marsal tracked global climates. Results from this study indicate that Neandertal prey species within the Dordogne Valley of France did not undertake long distance round-trip migrations in glacial or interglacial cycles, maintaining the possibility that local habitats did not change in differing climatic cycles. However, because Neandertals were nutritionally stressed the most likely conclusion is that glacial cycles decreased herbivore populations, thus stressing Neandertals. / Dissertation/Thesis / Ph.D. Anthropology 2012
10

Krisberedskap skogsbränder : Hur Sveriges kommuner arbetar med krisberedskap för skogsbränder / Wildfires and crisis management : how Swedish municipalities work with crisis management against wildfires

Bergquist, Ebba January 2022 (has links)
In February 2022 the Intergovernmental panel on climate change (IPCC) published a report indicating that wildfires may become more frequent as climate changes keeps progressing. The last few years we have witnessed devastating consequences due to wildfires around the world. In 2014 Sweden was affected by one of the biggest wildfires in modern history when a total of 15 000 hectares burned down. This study investigates how municipalities in Sweden work with crisis management against wildfires. Data was collected in a questionnaire sent out to municipalities as a web-survey. The questionnaire included questions about the municipality´s ability to handle a higher frequency of wildfires and if their risk and vulnerability analysis includes wildfires. The overall response rate was 52 % (151/290) and more than half of the municipalities answered that wildfires are included in their risk and vulnerability analysis, and they think they can manage a higher frequency of wildfires. It was not possible to identify a difference in crisis management between small (&lt;16 000) and large (&gt;16 000) municipalities, and municipalities located in the southern and northern parts of Sweden, respectively. What can be seen as worrying is that there are municipalities that do not have the capacity to handle an increase in wildfires. Economics are named one of the main reasons municipalities do not prioritize these issues. Due to the development with rising temperatures and more frequent wildfires in the world, forest fires will probably be a topical research area onwards.

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