• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 86
  • 34
  • 1
  • 1
  • Tagged with
  • 123
  • 123
  • 117
  • 49
  • 33
  • 32
  • 28
  • 25
  • 19
  • 17
  • 16
  • 15
  • 15
  • 15
  • 15
  • 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.
51

CLIMATE CHANGE AND THE ELECTRICAL DISTRIBUTION GRIDS OF GOTLAND AND KLINTEHAMN

Brinkhurst, Sean January 2023 (has links)
Climate change represents a critical threat to electrical infrastructure. With reliance on electricity expected to increase in Sweden due to the transition from fossil fuel based energy to greener energy sources, it is important that the reliability of the electrical grid be upheld. This thesis studies the potential climate affected effects of extreme precipitation, annual average temperature change, water pooling after 100/500-year rains, and sea level rise. The RCP scenarios used for extreme precipitation and temperature change are RCP 4.5 and RCP 8.5. These climate effects will be studied in this thesis to understand and determine the extent of the climate effects on the electrical grid of Gotland and Klintehamn. The possible issues on infrastructure that can be exacerbated by these climate effects will be presented. This thesis will use spatial analysis to find results using GIS as a tool. GIS will be used to compare the various climate effects over the electrical grid data. Data was received from various sources, extreme precipitation and temperature change were sourced from SMHI, water pooling, and sea level rise were sourced with permission from Region Gotland. The electrical grid data for both Gotland and Klintehamn was received from GEAB, this data is considered nationally sensitive information therefore the location of this data is not shown. The results generally show that climate change, no matter the scenario presents a threat to the infrastructure. Although it should be noted as well that the scenario will impact the severity of the effects. RCP 8.5 will likely have more of an effect for both extreme precipitation and temperature than RCP 4.5. Water pooling is expected to have a greater effect on the <20kV lines than on the 70kV infrastructure. Finally, sea level rise is expected to have a much greater effect from 2-meter sea level rise over the 1-meter sea level rise. The overarching theme found is that climate change will have impacts over the electrical grid.
52

CLIMATE FINANCE AND UNIVERSAL ENERGY ACCESS: ENERGY JUSTICE IN THE GREEN CLIMATE FUNDS PROJECTS TO PROMOTE ENERGY ACCESS IN AFRICA

Sjölén, Alice January 2023 (has links)
Climate finance is becoming an increasingly important aspect of climate change action, and massive sums are estimated to be required to mitigate further increase in greenhouse gas (GHG) emissions. Mitigation projects supported by climate finance further have the possibility to increase access to modern energy services in countries where these are lacking. Focusing on the Green Climate Fund (GCF) and the fund’s climate finance projects committed to enhancing energy access, this study investigates the complexities related to climate finance projects and what possible justice implications climate finance might result in. The area of focus in the study is the African continent, and the aspect of energy justice, specifically energy access equity. The study uses qualitative document analysis and reflexive thematic analysis along with an energy justice lens and framework, to analyse aspects of energy justice in six approved funding proposals of the GFCs energy generation and access portfolio. The results reveal three major overarching themes of a strong focus on private sector enhancement, where risk management and return on investments are common patterns in the approved funding proposals, site selection criteria that focus on financial viability and market potential, and a strong focus on finding a balance between affordability and profits. Resulting from this is likely to be an enhancement of energy access for the middle and low-income population in Africa, however, the results of the study show that energy justice implications resulting from the planned projects, particularly in terms of energy access equity are likely to arise. The themes found in the documents are likely to result in both distributive and recognition justice implications specifically affecting individuals, households and social groups living in extreme poverty or in areas deemed as undesirable for investments. It further highlights the need to consider already marginalised groups in society and not only financial viability of projects to attract private sector involvement. The study concludes that while private finance is positive in terms of climate finance, a balance between private and public finance is of importance, and increased focus must be put on the fairness and equity of energy access projects supported by climate finance from the Green Climate Fund.
53

Energy-saving impacts of intelligent speed guidance at signalized intersections for different driver behaviors and vehicle powertrains / Energibesparande effekter av intelligent hastighet vägledning vid signaliserade korsningar för olika förarbeteenden och fordonsdrivlinor

Yang, Yuxuan January 2022 (has links)
In order to control the energy consumed by vehicles for crossing signalized intersections, this project designs and tests a speed guidance energy-saving strategy for signalized intersections, taking drivers’ bounded rationality into consideration. This research achieves speed guidance by developing theoretical foundation of speed guidance, dividing scenarios for practise of speed guidance, and calculating optimal trajectories for vehicles. As for influence of bounded rationality, this research categorizes all drivers into three different types: aggressive drivers, normal drivers and conservative drivers. Numerical simulation of this research is focuses on a single intersection, with three traffic saturation level, represented by 346, 519 and 692 vehicles per hour. Considering the foreseeable popularization of electric cars (EV) in the close future, proportion of EV is also taken as a variable, and experiments are carried separately at three milestones of EV proportion: 0%, 30%, and 60%. The findings suggest that aggressive drivers benefit the most from the speed guidance in energy saving, and speed guidance does lest benefit to normal drivers. Both drivers’ bounded rationality and high traffic volume could lead to increase of energy consumption, while providing specifically modified speed guidance is able to achieve satisfying reductions to these effects. With increase of EVs’ proportion in the traffic flow and drop of overall energy consumption, effect of the guidance becomes comparatively worse than the previous non-EV performance of 7% to 11%, while remaining to be effective to cut off overall energy consumption by 5% to 8%. This research is able to improve normal speed guidance with more accurate and practicable guidance information for drivers in current traffic environment.
54

Damage Assessment of the 2022 Tongatapu Tsunami : With Remote Sensing / Skadebedömning av 2022 Tongatapu Tsunamin : Med Fjärranalys

Larsson, Milton January 2022 (has links)
The Island of Tongatapu, Tonga, was struck by a tsunami on January 15, 2022. Internet was cut off from the island, which made remote sensing a valuable tool for the assessment of damages. Through land cover classification, change vector analysis and log-ratio image differencing, damages caused by the tsunami were assessed remotely in this thesis. Damage assessment is a vital part of both assessing the need for humanitarian aid after a tsunami, but also lays the foundation for preventative measurements and reconstruction. The objective of this thesis was to assess damage in terms of square kilometers and create damage maps. It was also vital to assess the different methods and evaluate their accuracy. Results from this study could theoretically be combined with other damage assessments to evaluate different aspects of damage. It was also important to evaluate which methods would be good to use in a similar event. In this study Sentinel-1, Sentinel-2 and high-resolution Planet Imagery were used to conduct a damage assessment. Evaluating both moderate and high-resolution imagery in combination with SAR yielded plausible, but flawed results. Land cover was computed for moderate and high-resolution imagery using three types of classifiers. It was found that the Random Forest classifier outperforms both CART and Support Vector Machine classification for this study area.  Land cover composite image differencing for pre-and-post tsunami Sentinel-2 images achieved an accuracy of around 85%. Damage was estimated to be about 10.5 km^2. Land cover classification with high-resolution images gave higher accuracy. The total estimated damaged area was about 18 km^2. The high-resolution image classification was deemed to be the better method of urban damage assessment, with moderate-resolution imagery working well for regional damage assessment.  Change vector analysis provided plausible results when using Sentinel-2 with NDVI, NDMI, SAVI and BSI. NDVI was found to be the most comprehensive change indicator when compared to the other tested indices. The total estimated damage using all tested indices was roughly 7.6 km^2. Using the same method for Sentinel-1's VV and VH bands, the total damage was estimated to be 0.4 and 2.6 km^2 respectively. Log ratio for Sentinel-1 did not work well compared to change vector analysis. Issues with false positives occurred. Both log-ratios of VV and VH gave a similar total estimated damage of roughly 5.2 km^2.  Problems were caused by cloud cover and ash deposits. The analysis could have been improved by being consistent with the choice of dates for satellite images. Also, balancing classification samples and using high-resolution land cover classification on specific areas of interest indicated by regional methods. This would circumvent problems with ash, as reducing the study area would make more high-resolution imagery available.
55

Lågstadielärares upplevda utmaningar med klimatundervisning inom de naturorienterande ämnena / Primary School Teachers’ Experienced Challenges with Climate Education in Natural Science Education

Forss, Matilda, Friberg, Li January 2023 (has links)
Klimatförändringar är i dagens samhälle ett påtagligt problem och skolans uppdrag är att lära ut området för unga. Det komplexa ämnet kan orsaka utmaningar och känslor, specifikt klimatångest, som lärare tvingas hantera för att stödja elever att bli medvetna och uppmuntrade till att arbeta för hållbar utveckling. Däremot behandlas inte klimatförändringar i någon större utsträckning i det centrala innehållet i läroplanen för NO-ämnena i årskurs 1-3.  Syftet med studien är att undersöka lärares upplevda utmaningar med klimatundervisning inom NO-ämnena i de lägre årskurserna och hur dessa hanteras. Studien syftar även till att undersöka hur NO-lärare hanterar klimatångest i undervisningen.  Studien genomfördes med semistrukturerade intervjuer med fem NO-lärare för årskurs F- 3 och materialet analyserades genom tematisk analysmetod. Analysen utgår från teoretiska begrepp, exempelvis klimatångest och eco-anxiety, samt känslohanteringsstrategier för att diskutera resultatet.  Resultatet visar att de utmaningar NO-lärarna såg var nivåanpassning, media, lärarnas egna engagemang samt kunskaper och transparens. Engagemang var den mest uttalade positiva känslan lärarna upplevde hos både sig själva och eleverna. Negativa känslor som klimatångest och oro var synligt hos lärare och elever. Lärarna hanterade utmaningarna genom att börja klimatundervisningen tidigt och inte ignorera fenomenet. De arbetade även elevnära och lösningsfokuserat.  Utifrån resultatet blir det synligt att klimatångest skulle kunna ses som en stor utmaning med NO- och klimatundervisning på lågstadiet. Lärarnas erfarenheter av hantering av klimatångest som utmaning utgår mestadels från menings- och problemfokuserade strategier och i mindre grad emotionsfokuserade hanteringsstrategier.
56

Det sårbara hållbara samhället : En studie om elmarknadens förutsättningar utifrån klimat och väder i en Sydsvensk kontext / The vulnerable sustainable society : A study concerning the powermarket's situation in regards to climate and weather in a southern Swedish context

Tedestam, Joel January 2023 (has links)
Syfte Syftet är att utreda kopplingen mellan väder och elproduktion i ett begränsat sydsvensktområde; elområde 4. Metod Arbetet kommer att utföras med en kvantitativ och en kvalitativ metod. Den kvantitativametoden innefattar den största delen av den empiriska huvudundersökningen och utgörs avinsamlad data från SMHI och Nordpool. Det kvantitativa materialet kommer att redogöras föri diagramform vilket utgör grunden för den kvalitativa analysen. Begreppet hållbarhetkommer att figurera som en central punkt för arbetets utformning. Resultat Resultaten består av väder- och klimatdata från ett antal utvalda väderstationer i elområde 4vilka visar på hur olika väderförutsättningar skapar trender för elproduktion. Kustnäraområden har väderkontexter som lämpas bäst för placering av vindkraftverk. Områden iinlandet är mer problematiska och måste utvärderas individuellt för lämplighet förvindkraftsparker. Temperaturerna i elområde 4 visar på en regional sänkning av temperaturenunder slutet av november 2022. I resultaten finns även en betydande undersökning omelmarknadens förutsättningar i elområde 4, främst då med tanke på elproduktion och elprisersamt elhandel. Elproduktionen i elområde 4 är i huvudsak beroende av vindkraft ochsamtidigt finns det ett stort behov av elhandel med andra elområden. Slutsats Kopplingen mellan väder och elpriser är tydligast inom två kategorier, nämligen elproduktionoch elkonsumtion. Elproduktionen varierar kraftigt från dag till dag beroende påvindhastigheten, vilken i sin tur skapar förutsättningar för vindkraften som elområde 4 ärberoende av. Över tid har vindkraftverken en rimlig förmåga att producera el men från dag tilldag kan elproduktionen och därmed även elpriserna variera oerhört mycket. Elkonsumtionensyftar främst på behovet av uppvärmning vilket är onekligt sammankopplat med höjningaroch sänkningar i temperaturen. Det är temperaturförändringar som styr de störreförändringarna i elmarknadens balans mellan produktion och konsumtion. Vid mycket kallatemperaturer kan inte elproduktionen längre hålla jämna steg med konsumtionen ochelpriserna skjuter i höjden.
57

Possibilities of rewetting agricultural land for decreasing greenhouse gas emission and sustainable adaptation to flooding : -A case study from two sites in Sweden

Lamin, Noore Wazid January 2015 (has links)
The consequence of climate change will be more flooding in some areas and problems with sea-level rise. Drained wetlands and lakes that today are used for agriculture in the future may need to be rewetted because it might be unsustainable to continue to drain them. Rewetting these lands will have many positive effects like for instance decreased greenhouse gas emissions since these lands due to their high organic matter content are emitting a lot of CO2 and N2O. In this study two sites that could become candidates for rewetting have been studied and compared for their CO2 and N2O emissions. This was done by using a method for sampling gases both from a closed chamber and directly from soil. The emission rates were higher for Ramsjön compared to Vesan for both gases that could probably be an effect of season. A strong covariation between the two gases was shown for Ramsjön and the relationship was fairly strong for Vesan this indicates a common process for releasing the two gases. Rewetting these areas would probably have a high potential for saving greenhouse gas emissions and possibly also serve as flood adaptation areas with a high biodiversity and recreational value.
58

Beyond Conservation: Unlocking livelihoods, empowering communities : The case of Mamirauá

Leon Lavandera, Alejandra January 2023 (has links)
The spread of Community-based Natural Resources Management (CBNRM) programs can be attributed to the failure of top-down approaches and the development of more equitable governance strategies. A CBNRM approach seeks to fulfill dual objectives by balancing environmental conservation goals and local livelihood opportunities. This thesis analyzes how the implementation of CBNRM programs at Mamirauá Sustainable Development Reserve (MSDR) influences the available livelihood opportunities for local communities. Data was gathered through document analysis and online qualitative interviews and questionnaires with MSDR's staff, directly involved with these programs. The study found that trust, empowerment, and engagement are crucial for the effective implementation of these programs. By including local knowledge, promoting community participation and organization, providing continuous training, and having an ongoing evaluation and adaptation approach when managing resources, MSDR balances conservation goals with local development. Additionally, results indicate that the existing challenges are related to the efficacy of policy and legislative frameworks at the local and national levels, which complicates the work of implementing organizations. The findings suggest that a participatory approach to conservation can lead to positive outcomes, highlighting the importance of sustainable development within protected areas. These results have implications for future CBNRM projects and deepen our understanding of the intrinsic relationship between nature conservation and local livelihoods.
59

A Laminated Carbonate Record of Late Holocene Precipitation from Martin Lake, LaGrange County, Indiana

Stamps, Lucas G. 01 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Precipitation trends and their driving mechanisms are examined over a variety of spatial and temporal scales using a multi-proxy, decadally-resolved sediment record from Martin Lake that spans the last 2300 years. This unique archive from a northern Indiana kettle lake documents significant climate variability during the last 2 millennia and shows that the Midwest has experienced a wide range of precipitation regimes in the late Holocene. Three independent proxies (i.e., oxygen and carbon isotopes of authigenic carbonate and %lithics) record variations in synoptic, in-lake and watershed processes related to hydroclimate forcing, respectively. Together, these proxies reveal enhanced summer conditions, with a long period of water column stratification and enhanced summer rainfall from 450 to 1200 CE, a period of time that includes the so-called Medieval Climate Anomaly (950-1300 CE). During the Little Ice Age, from 1260 to 1800 CE, the three proxy records all indicate drought, with decreased summer rainfall and storm events along with decreased lake stratification. The Martin Lake multi-proxy record tracks other Midwest climate records that record water table levels and is out-of-phase with hydroclimate records of warm season precipitation from the High Plains and western United States. This reveals a potential warm season precipitation dipole between the Midwest and western United States that accounts for the spatial pattern of late Holocene drought variability (i.e., when the Midwest is dry, the High Plains and the western United States are wet, and vice versa). The spatiotemporal patterns of late Holocene North American droughts are consistent with hydroclimate anomalies associated with mean state changes in the Pacific North American teleconnection (PNA). Close associations between late Holocene North American hydroclimate and records of Northern Hemisphere temperatures and the Pacific Ocean-atmosphere system suggests a mechanistic linkage between these components of the global climate system that is in line with observational data and climate models. Based on our results, predominantly –PNA conditions and enhanced Midwestern summer precipitation events are likely to result from continued warming of the climate system. In the western United States, current drought conditions could represent the new mean hydroclimate state.
60

Dekomponeringsanalys av personbilstrafikens CO2-utsläpp i Sverige 1990–2015

Kalla, Christelle January 2019 (has links)
År 2045 ska Sverige uppnå territoriella nettonollutsläpp och till år 2030 ska utsläppen från transportsektorn ha minskat med 70 % jämfört med år 2010. Sveriges vägtrafik står för en tredjedel av de totala växthusgasutsläppen. För att uppnå klimatmålen bör de mest lämpade styrmedlen och åtgärderna prioriteras. En systematisk undersökning av de faktorer som påverkat utsläppsutvecklingen kan vägleda beslutsfattare att fördela resurserna där de gör mest nytta. Dekomponeringsanalys är en potentiell metod för detta syfte då flera olika faktorers effekter kan särskiljs och mätas. Fem additiva LMDI-I dekomponeringsanalyser genomfördes på utsläppsutvecklingen av fossilt CO2 inom personbilstrafiken mellan åren 1990–2015. De faktorer som undersöktes var befolkning, bil per capita, bränsleteknologier, motorstorlekar, trafikarbete per bil, emissioner och biobränsle. Data från emissionsmodellen HBEFA, Trafikverket och SCB användes i analyserna. Under hela perioden 1990–2015 minskade CO2-utsläppen och dekomponeringsanalyserna visade att alla de ingående faktorerna påverkat utvecklingen. Sett över hela tidsperioden 1990–2015 hade faktorerna påverkat utvecklingen mest i storleksordningen trafikarbete per bil (35 %), bränsleteknologier (15 %), befolkning (15 %), bil per capita (13 %), emissioner (11 %), biobränsle (7 %) samt motorstorlekar (5 %). Procenten anger andelen som faktorn utgjorde av effekternas absoluta summa. Trafikarbete per bil, emissioner, biobränsle och motorstorlekar minskade utsläppen. Bränsleteknologier, befolkning och bil per capita ökade utsläppen. Resultaten kan användas som en indikation för vilka faktorer som kan påverka den framtida utsläppsutvecklingen mest och för vilka åtgärder bör vidtas. Åtgärderförslag är incitament för att välja mer hållbara transportsätt, öka andelen av bilar med lägre utsläpp i fordonsflottan och använda mer biobränsle. / By year 2045 Sweden shall reach zero territorial net emissions and by year 2030 the emissions from the transport sector shall be reduced by 70% compared to year 2010. In Sweden the road traffic stands for a third of the total greenhouse gas emissions. In order to achieve the climate targets, the most suited policies and actions should be prioritized. A systematic investigation into the factors that affect the change in emissions can guide decision makers to distribute resources where they contribute the most. A decomposition analysis is a potential method for this purpose since the effect of different factors can be separated and measured. Five additive LMDI-I decomposition analyses were made on the change in fossil CO2 emission from passenger cars in Sweden between year 1990–2015. The factors that were investigated were: population, vehicle per capita, fuel technologies, engine sizes, distance travelled per vehicle, emissions and biofuel share. Data from the emissions model HBEFA, the Swedish Transport Administration and Statistics Sweden were used in the analyses. During the period of year 1990–2015 the CO2 emissions were reduced, and the decomposition analyses showed that all ingoing factors affected the change. Throughout the period the factors that contributed the most were in order of size: distance travelled per vehicle (35%), fuel technologies (15%), population (15%), car per capita (13%), emissions (11%), biofuel (7%) and engine size (5%). The percentage is the share of the factor’s effect of the absolute sum of all the different effects. Distance travelled per vehicle, emissions, bio fuels and engine size reduced the emissions. Fuel technologies, population and car per capita increased the emissions. The suggestions of actions are incentive for people to use more sustainable means for transportation, increase the share of cars with lower emissions in the fleet and use more biofuel.

Page generated in 0.066 seconds