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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

Využitelnost indexů konektivity krajiny jako prediktorů výskytu druhů / Usability of connectivity metrics as predictors of species distribution

Kučera, Michal January 2016 (has links)
The aim of this thesis is to evaluate whether connectivity indices are usable for bird prediction. The study area contains of the whole country but is divided into separate squares with area of 133 km 2 each, where the presence or absence of the bird species is known. The dependence is tested on landscape connectivity indices presented by prof. S. Saura. The land cover contains of Corine land cover 2012 data. The results will be evaluated with logistic regression approach on sample data including 4 different dispersal distances (500 m, 1 000 m, 2 000 m and 3 000 m) and 10 specific bird species typical for given land cover. The corelation between land cover area presence of the bird is also tested.
2

Carbon dioxide in agricultural streams : Magnitude and patterns of an understudied atmospheric carbon source

Osterman, My January 2018 (has links)
The role of streams in the global carbon budget was for a long time neglected, since they were considered passive transporters of carbon from land to sea. However, studies have shown that streams are often supersaturated in carbon dioxide (CO2), making them sources of carbon to the atmosphere. The main sources of stream CO2 are in-stream mineralization of organic matter and transport of carbon from the catchment. The catchment derived CO2 could both be of biogenic (respiration) or geogenic (weathering) origin. Most studies regarding the topic rely on measurements carried out in forest-dominated catchments, while agricultural streams are under-represented. The objective of this study was to examine partial pressure of CO2 (pCO2) in streams in catchments dominated by agriculture. This was done to increase the knowledge about agricultural influence on stream pCO2, and to provide a basis for planning mitigation strategies for reducing CO2 emissions from the agriculture sector. Sampling was performed in ten streams draining agriculture-dominated catchments around Uppsala, Sweden, from June to November 2017. Measurements of pCO2 were carried out with floating chambers, equipped with CO2 sensors. Nutrients, organic carbon, discharge and different chemical variables were also measured. For correlation tests, the method Kendall’s Tau was used. Catchments were delineated in a geographic information system (GIS) and the CORINE Land Cover dataset was used to examine land use. Stream specific median pCO2 varied from 3000 to 10 000 μatm. In some streams, pCO2 exceeded 10 000 μatm, which was outside of the sensor’s measurement range. Values of pCO2 were high compared to similar studies in forested catchments, which could indicate that occurrence of agriculture in the catchment increases stream CO2. Correlation was found between pCO2 and discharge, with negative correlation in five streams and positive correlation in two. Negative correlation was found between pCO2 and pH and percentage of dissolved oxygen, respectively. No significant correlation was found between pCO2 and fraction of agricultural land use, nutrients or organic carbon. Further studies are needed to examine the sources of CO2, since it is possible that a large part of the CO2 has a geogenic origin. The floating chamber method should be revised to reduce the sensor’s sensitivity to condensation and cold temperatures, and to increase the measuring range.
3

Hodnocení změn pokryvu Země pomocí objektových detekcí / Evaluation of Land Cover Changes Using the Object Detections

Skokanová, Eliška January 2011 (has links)
The aim of the project is to perform object based change detection of land cover in specific areas of Czech republic. Landsat 2000 and Spot 2006 satellite images are used as input data. The method used for evaluation of changes is Multivariate Alteration Detection unsupervised method which is based on statistical procedures and is available from e-Cognition software. The results of detection are compared with Corine Land Cover changes database to evaluate degree of parity on detected areas. Different mapping unit is used to be able to detect smaller changes than Corine database. First part of the work is review of literature sources aimed on processing of satellite images, description of the spectral behavior of landscape objects, origins of Corine Land Cover database and principle of change detection using MAD. Second part deals with data adjustment, change detection process and comparison of reached results with Corine. Keywords: object based change detection, satellite images, Corine Land Cover, mapping unit of changes, Multivariate Alteration Detection, e-Cognition
4

The multi-criteria assessment of ecosystem services at a landscape level to support decision-making in regional and landscape planning / Die multikriterielle Erfassung von Ökosystemdienstleistungen auf Landschaftsebene zur Unterstützung der Entscheidungsfindung in der Regional- und Landschaftsplanung

Koschke, Lars 25 February 2016 (has links) (PDF)
The growing pressure on natural resources and biodiversity has led to a widespread acknowledgement of the services nature provides for humans. The appropriate representation of the benefits of sustainable land use in decision-making is still a challenge and tools that facilitate land use planning processes are needed. The dissertation presents a multicriteria assessment approach for a qualitative estimation of regional potentials to provide ecosystem services. This approach has been applied in several case studies in Saxony, Eastern Germany and Brasil. The ecosystem services concept builts the methodological framework for the assessment as it offers a universal approach to evaluate the impact of Land use/ Land cover change (LULCC) on human well-being. Since standardized methodical approaches for ecosystem services assessment at the landscape level are lacking, a particular requirement was to conceive a method that is easily transferable to other case study areas. Further the method should enable the use of existing and easily available environmental data, and it should be transparent for stakeholders and decision makers. The results of our study show that the combination of selected ecosystem services and land cover data such as CORINE Land Cover (CLC) can contribute to regional planning by communicating the effect of LULCC on ecosystem services, especially when applied as an evaluation basis in the tool GISCAME. The approach supports also the assessment of the performance of a region to provide ecosystem services and the comparison of regions towards this aspect. In the discussion section, the limitations of the developed approach are discussed. Main sources of uncertainty are related to coarse land cover data, lacking knowledge on the provision of ecosystem services at a landscape scale, and the difficulty to make relevant the ecosystem services concept in regional planning processes.
5

Les formes des villes européennes vues du ciel. Une contribution de l'image CORINE Land cover à la comparaison morphologique des grandes villes d'Europe occidentale.

Guérois, Marianne 16 December 2003 (has links) (PDF)
La question de la forme urbaine s'est affirmée depuis une dizaine d'années comme une priorité des réflexions sur le devenir des villes européennes. Soulevée en réaction au processus d'étalement urbain, cette question est de plus portée par l'émergence de la notion de développement urbain durable et par les débats qu'elle anime quant aux bien-fondés d'un modèle de ville compacte et dense. Ces discussions ne sont cependant que rarement étayées par des mesures comparables car les bases de données sur les villes européennes sont toujours en cours de constitution. <br /><br />La cartographie des espaces bâtis restituée par l'image CORINE Land cover vers 1990 est une source inédite qui, croisée avec les données de population, nous a permis d'établir un ensemble de repères pour comparer les formes des villes considérées à l'échelle de la tache urbaine. Malgré la complexité des processus en jeu et par-delà la spécificité des situations locales, nous avons ainsi interrogé le rôle de logiques générales relatives à la taille des villes, à leur appartenance nationale ou à différents contextes de peuplement régionaux, pour rendre compte de la diversité des formes observées en Europe occidentale.<br /><br />Dans le cadre des agglomérations, deux dimensions de la compacité, l'une relative à l'emprise physique des villes (étendue et densité), l'autre à leur configuration spatiale (forme des taches urbaines), ont été croisées pour vérifier et nuancer l'importance d'un gradient nord-sud de la compacité urbaine en Europe. Dans le cadre élargi d'aires urbanisées, le modèle du champ urbain ressort encore comme un principe fort d'organisation des espaces bâtis, selon un double gradient linéaire, très contrasté dans les limites de l'agglomération, plus diffus dans les espaces périurbains. Pour quelques grandes régions urbaines, l'application de méthodes de lissage a permis, en généralisant l'image des surfaces bâties à plusieurs échelles, de restituer différentes structures hiérarchiques du peuplement, plutôt monocentriques ou polycentriques. Ces premières explorations ont établi des résultats qui seront confrontés à la prochaine version de CORINE, disponible en 2004.
6

The multi-criteria assessment of ecosystem services at a landscape level to support decision-making in regional and landscape planning

Koschke, Lars 24 April 2015 (has links)
The growing pressure on natural resources and biodiversity has led to a widespread acknowledgement of the services nature provides for humans. The appropriate representation of the benefits of sustainable land use in decision-making is still a challenge and tools that facilitate land use planning processes are needed. The dissertation presents a multicriteria assessment approach for a qualitative estimation of regional potentials to provide ecosystem services. This approach has been applied in several case studies in Saxony, Eastern Germany and Brasil. The ecosystem services concept builts the methodological framework for the assessment as it offers a universal approach to evaluate the impact of Land use/ Land cover change (LULCC) on human well-being. Since standardized methodical approaches for ecosystem services assessment at the landscape level are lacking, a particular requirement was to conceive a method that is easily transferable to other case study areas. Further the method should enable the use of existing and easily available environmental data, and it should be transparent for stakeholders and decision makers. The results of our study show that the combination of selected ecosystem services and land cover data such as CORINE Land Cover (CLC) can contribute to regional planning by communicating the effect of LULCC on ecosystem services, especially when applied as an evaluation basis in the tool GISCAME. The approach supports also the assessment of the performance of a region to provide ecosystem services and the comparison of regions towards this aspect. In the discussion section, the limitations of the developed approach are discussed. Main sources of uncertainty are related to coarse land cover data, lacking knowledge on the provision of ecosystem services at a landscape scale, and the difficulty to make relevant the ecosystem services concept in regional planning processes.
7

Spatial and Temporal Dynamics of  Carbon Sequestration in Stockholm  County's Green areas : A GIS-based Analysis / Kolbindningsdynamiken i Stockholm Läns Grönområden genom Tid : En GIS-baserad Analys

Kareflod, Victoria January 2023 (has links)
The human influence of global climate is an issue currently assessed in various mitigation strategies. Stockholm County has committed to becoming carbon neutral by 2040 and negative by 2045 according to the Paris agreement. The strategy includes cutting of various sectors emissions as well as compensating for remaining emissions with carbon sequestration methods. Accounting for ecosystems ability to sequester carbon at local level in green urban areas is an important in carbon offset efforts. It has emerged from previous research that the sequestration rate may differ depending on vegetation age and thus time passing, which is not assessed on a regional level, which is important for carbon offset efforts to accurately account for the sequestration potential in long-term mitigation strategies. This study therefore aims to fill the knowledge gap of how the temporal aspect affects the current sequestration potential and future predictions, as well as assessing how it can aid in reaching carbon neutrality by 2040. The study are thus aiming to answer the research questions (1) how the carbon sequestration potential of the existing green areas change over time in Stockholm County, (2) if additional measures need to be taken to preserve or increase carbon sequestration to maintain carbon neutrality until 2040 and (3) how the knowledge of sequestration dynamics aid in reaching a carbon neutral city by 2040. A weighing of which Corine Land Cover categories was performed and concluded in the including; discontinuous structures, green urban areas, forests and wetlands, due to their contribution to sequestration potential, estimated change through time, and relevance for Stockholm County. The spatial analysis was made based on calculations with information obtained from processing of obtained data on land cover and species distribution as well as scientific literature on sequestration rates of each vegetation across all life stages, where Net Ecosystem Production was the main measurement used. The estimated results were computed in a Geographic Information System to simulate and visualize the sequestration rates of current and future predictions of 2040 sequestration potential as well as locating areas of interest. The findings show that by including temporal aspects to the assessment of carbon sequestration potential in Stockholm County, the current and future sequestration potential increased from previous research estimations. The total current sequestration potential was 2,8 MtCO2-eq annually and the predictions were estimated to 3,3 MtCO2-eq per year in 2040. As the current emissions in Stockholm County are currently 6 MtCO2-eq per year, the natural sequestration potential provided by the green areas is compensating for 46% of the current emissions. As the estimated future emissions are 0,95 MtCO2-eq annually, the natural sequestration potential more than compensates for the emissions in the county, if the predicted emission reductions are realized. Although further measurements are not seemingly required to achieve carbon neutrality in 2040, the findings further locate areas and species where management practices or protection is beneficial to further add to the sequestration potential of Stockholm County. / Den mänskliga påverkan på det globala klimatet är ett problem som för närvarande bedöms i olika klimatåtgärder. Stockholms län har förbundit sig till ett mål att bli koldioxidneutralt till 2040 och koldioxidnegativt till 2045 enligt Parisavtalets överenskommelser. Strategin innefattar att minska utsläppen från olika sektorer samt att kompensera de återstående utsläppen med olika metoder för koldioxidlagring. Ekosystemens förmåga att binda kol på lokal nivå i gröna stadsområden är en viktig del av ansträngningarna för att kompensera för utsläppen. Det har varit uppenbart från tidigare forskning att potentialen av koldioxidlagring kan skilja sig åt beroende på vegetationens ålder samt passerande tid, även om aktuell forskning inte omfattar frågan på regional nivå, vilket är viktigt för insatser som omfattar koldioxidkompensation så att lagringspotentialen kan redovisas korrekt i de långsiktiga klimatåtgärderna. Denna studie syftar därför till att fylla kunskapsluckan gällande hur den tidsmässiga aspekten påverkar den befintliga lagringspotentialen och framtida prognoser samt hur det kan bidra till att nå koldioxidneutralitet fram till 2040. Studien avser därmed till att svara på forskningsfrågorna (1) hur kolbindningspotentialen för de befintliga grönområdena förändras över tid i Stockholms län, (2) ifall ytterligare åtgärder behöver vidtas för att bevara eller öka koldioxidbindningen för att uppnå eller bibehålla koldioxidneutralitet fram till 2040 och (3) hur kunskapen om koldioxidlagringsdynamiken underlättar för att nå en koldioxidneutral region år 2040. En avvägning av vilka Corina marktäckeskategorier utfördes och resulterade i inkludering av; diskontinuerliga strukturer, gröna stadsområden, skogar och våtmarker, där koldynamiken och omfattningen av lagringspotentialen var relevant för Stockholmsregionen. Den rumsliga analysen gjordes baserad på beräkningar med information erhållen genom bearbetning av införskaffad data om marktäcke och artfördelning samt vetenskaplig litteratur om kolbindningshastighet för varje vegetation över alla livsstadier, där Net Ecosystem Production var det huvudsakliga måttet. De uppskattade resultaten beräknades i ett Geografiskt Informationssystem för att simulera och visualisera lagringshastigheten för nuvarande och framtida förutsägelser om sekvestreringspotentialen år 2040 samt att lokalisera intressanta. Resultaten visar att genom att inkludera tidsmässiga aspekter i bedömningen av kolbindningspotentialen i Stockholms län ökade den nuvarande och framtida bindningspotentialen från tidigare forsknings uppskattningar. Den totala nuvarande lagringspotentialen var 2,8 MtCO2-ekv årligen och de framtida prognoserna uppskattades till 3,3 MtCO2-ekv årligen år 2040. Eftersom de nuvarande utsläppen i Stockholms län för närvarande är 6 MtCO2-ekv årligen, kunde man se att den naturliga lagringspotentialen som grönområdena avsåg, kompenserar för 46 % av de nuvarande utsläppen. Eftersom de beräknade framtida utsläppen är 0,95 MtCO2-ekv per år, mer än kompenserar de gröna områdena för de utsläpp som sker i länet, om den förutsedda reduceringen av utsläppen sker. Även om ytterligare mätningar inte tycks behövas för att uppnå koldioxidneutralitet till 2040, lokaliseras ytterligare områden samt arter i resultatet där förvaltning eller skydd är fördelaktiga för att ytterligare förbättra lagringspotentialen i Stockholms län.

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