289 research outputs found

    Object-Based Classification of Vegetation at Stordalen Mire near Abisko by using High-Resolution Aerial Imagery

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    The focus of this work is to investigate and apply the remote sensing method of object-based image analysis (OBIA) for vegetation classification of a permafrost underlain peatland in sub-arctic Sweden, by using aerial imagery of high resolution. Since the northern landscapes are an important source of naturally stored CH4 and CO2, their contribution to the global carbon cycle is a focus in research about climate change and the global methane exchange. Climate change affects permafrost soils by future increases in the mean temperature and precipitation. It further influences the depth of the frozen layer, and the thickness of the active layer above permafrost increases. This complex relationship results into a changing future landscape distribution of the vegetation at permafrost peatlands. The change has an effect on the exchange of CH4 in particular permafrost areas. For that reason, knowledge about the vegetation distribution of plant communities is interesting for ecological studies. In this work, the observed area is Stordalen mire, which is situated in Swedish Lapland. At this peatland, a landscape change is currently visible as it occurs as variations in the vegetation pattern above the permafrost and by an obvious permafrost thaw. A number of studies focus on the mire and the place has a long history of research in climate change. So far, there is no detailed vegetation map of Stordalen available, indicating the relative spatial distribution of vegetation. Therefore, the main aim is to use a suitable technique to derive a detailed vegetation map by supervised classification. To carry out the information needed, digital aerial photography of high spatial resolution was used. The extraction of thematic information from that data was done by a combination of OBIA methods. Remote sensing has the capability to explore distant regions, and the usage of digital aerial imagery of high resolution allowed to captures the small size of structures of vegetation. It was possible to identify single plant communities from the data, and this information was taken out as vegetation classes. The presented work includes the preprocessing of the data, the segmentation of image objects, establishment of classification controls, set up of training areas, and the image classification to the vegetation map, finally with an evaluation of the results. The resulted map is a contribution to apply OBIA as a method for landscape analysis in future research about northern peatlands. Key words: Physical Geography and Ecosystem Analysis, Object-Based Image Analysis, OBIA, Vegetation Classification, Permafrost, Arctic Peatland, Remote Sensing, Aerial Photography, Environmental Monitoring, Landscape Analysis Advisor: Andreas Persson Master degree project 30 credits in Geomatics, 2014 Department of Physical Geography and Ecosystems Science, Lund University Student thesis series INES nr 323Northern peatlands play an important role in the observation of global climate variations. Permafrost in the ground is melting slowly, because the earth becomes warmer. This tends to result in increasing methane gas emissions from the ground. The impact of degradation is visible in a changing land cover distribution at the peatlands, because the landscape faces a change into moister conditions. Understanding the relation to climate conditions of the future is a challenge. No accurate information about the particular vegetation of peatlands exists. More knowledge about the vegetation cover would help to understand the effects from loosing permafrost in peatlands. It is also a useful source for a long- term observation of landscape changes. In our work, the objective was to derive a map that shows a detailed vegetation distribution of a permafrost underlain area. This was done by a classification of an aerial photography. Because Swedish Lapland is far from populated places, remote sensing is a welcome method to observe the ground vegetation from above. This is commonly done by interpreting photos taken by an aircraft. Our method involves an approach of object- based image analysis. We classify the information from an aircraft-taken image in a meaningful context into groups of vegetation covering the land surface. We produce a detailed vegetation map that helps to explore the vegetation and to observe changes. Background Remains from the last ice age characterize the subarctic landscape of Swedish Lapland. Large areas are still underlain by a constantly frozen ground, permafrost. The regions of permafrost exhibit wetlands that are often peatlands. We know that the permafrost ground layer is sensitive to changes in local climates. An obvious effect, the trend to warmer temperatures and to more rainfall, is that the landscape changes slowly by that. Landscape transformation is highly visible by ongoing ground degradation. This causes an increase in the disturbance of wetlands. The plant cover is affected, as vegetation pattern is connected to the conditions in the ground. In subarctic regions, the plant species distribution covering a peatland is defined by water access. The production of methane, a greenhouse gas, is also connected to water accessibility. Water covered permafrost drives the release of methane to the atmosphere. A better knowledge about ongoing processes within the peatland ecosystems and permafrost disappearance is important. Study Site and Data Northernmost Sweden, Lapland, is a region where peatlands are commonly found. We use an aerial photography that shows the area of a peatland that is underlain by permafrost. The digital image was taken during the growing season. Our study site, Stordalen, is a peatland close to the Abisko Scientific Research Station near lake Torneträsk. Stordalen is a peatland which has a frozen permafrost ground at different stages of degradation. Permafrost is already melting in some places, which suits the area for a closer observation. The used image has a high pixel resolution of 8 cm, which is in higher resolution than other available data of the area. Such high resolution enables to identify a high level of details of the vegetation cover. Image Classification A classification based on aerial imagery is a common technique. Traditional methods are based on a classification of every single pixel the image contains, and hereby considering the spectral information only. But this approach may lead to some problems, as one plant growing naturally consists of more than one pixel in a high- resolution image, as ours. The imagination that most plants covering the ground, e.g. patches of mosses, are naturally larger than 8 cm helps to understand this. We used the approach of an object-based interpretation, which enables a deeper influence on the classification, on the other hand. By the help of parameters and rule setting, object-based allows to capture typical pixel values that form a plant. Our method of object creation enables to include structures of different and very small sizes, so the plant cover is described following the natural shape. Main plant species are collected in vegetation groups that describe the type of plants by their growth form. Such a group is based on common characteristics. This classification method proposes the comparability of the vegetation classes. Using objects also enables new possibilities to analyze the vegetation. Results and Conclusions A map showing the distribution of vegetation at Stordalen peatland was obtained from the image. The work included tests of different parameters, the adjustment of the object size, shape and location. Typically, a vegetation object was identified by the spectral response of the plant surface in the image. A visual inspection, based on field knowledge, helped to determine the best parameters. The evaluation was done by comparing information from a field survey to the classification results. It was possible to produce a map that contains vegetation classes that follow the natural growth. Therefore, the combination of an object-based image analysis with high resolution data is of use to map the vegetation of a peatland. More knowledge about the actual vegetation, to evaluate the classification result, could improve future map results. Key words: Physical Geography and Ecosystem Analysis, Object-Based Image Analysis, OBIA, Vegetation Classification, Permafrost, Arctic Peatland, Remote Sensing, Aerial Photography, Environmental Monitoring, Landscape Analysis Original title: Marco Giljum (2014) Object-Based Classification of Vegetation at Stordalen Mire near Abisko by using High-Resolution Aerial Imagery Advisor: Andreas Persson Master degree project 30 credits in Geomatics, 2014 Department of Physical Geography and Ecosystems Science, Lund University Student thesis series INES nr 32

    International Trade, Material Flows and Land Use: Developing a Physical Trade Balance for the European Union

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    The environmental impacts of globalization and further liberalization of international trade today are on the top of the policy agenda in a number of international organizations. While the trade relations between two countries or regions may be balanced in monetary terms, they may at the same time be characterized by a substantial inequality with regard to the flows of natural resources. Thus some regions may systematically exploit the ecological capacity of other regions by importing resource intensive products and exporting wastes. In the last 10 to 15 years there has been extensive research on material flows mainly on the national level. However, empirical studies on material flows in international trade so far are very limited. In the last few years studies have been presented, which link material flow accounting and input-output analysis (based on monetary input-output tables) for the calculation of indirect material flows through intermediate production. This procedure has also been applied for calculating direct and indirect land appropriation. The compilation of the first physical input-output tables for some western European countries in the 1990s opened new possibilities for linking physical accounting and input-output analysis. Physical input-output analysis has so far been applied only for selected materials in single-country studies. It has neither been used for assessments of material flows in international trade nor for any land-related studies. In this report first steps towards the elaboration of a physical trade balance for the EU-15 are undertaken. Concerning the methodology of input-output analysis, three alternative approaches will be presented and discussed. In the empirical part, a physical trade balance for direct material flows of the EU is presented, disaggregated by world regions as well as product and material groups. In order to assess indirect resource requirements induced by imports and exports, a physical input-output model for the EU-15 is developed, based on physical input-output tables already published. This model is then used for assessing the overall resource requirements for the production of exports from EU-15 to the rest of the world. By applying physical input-output analysis, direct and indirect resource requirements will be calculated concerning both material flows and land appropriation

    Towards a comprehensive framework of the relationships between resource footprints, quality of life and economic development

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    The relationship between economic affluence, quality of life and environmental implications of production and consumption activities is a recurring issue in sustainability discussions. A number of studies examined selected relationships, but the general implications for future development directions of countries at different development stages are hardly addressed. In this paper, we use a global dataset with 173 countries to assess the overall relationship between resource footprints, quality of life and economic development over the period of 1990-2015. We select the Material Footprint and Carbon Footprint and contrast them with the Human Development Index, the Happiness Index and GDP per capita. Regression analyses show that the relationship between various resource footprints and quality of life generally follows a logarithmic path of development, while resource footprints and GDP per capita are linearly connected. From the empirical results, we derive a generalised path of development and cluster countries along this path. Within this comprehensive framework, we discuss options to change the path to respect planetary and social boundaries through a combination of resource efficiency increases, substitution of industries and sufficiency of consumption. We conclude that decoupling and green growth will not realise sustainable development, if planetary boundaries have already been transgressed.Series: Ecological Economic Paper

    Do mining activities foster regional development? Evidence from Latin America in a spatial econometric framework

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    Against the backdrop of steadily increasing global raw material demand, the socio-economic implications of metal ore extraction in developing countries are of major interest in academic and policy debates. This work investigates whether mining activities relate to the economic performance of mining regions and their surrounding areas. Usually, subnational impact assessments of mining activities are conducted in the form of qualitative in-field case studies and focus on a smaller sample of mining properties and regions. In contrast, we exploit a panel of 32 Mexican, 24 Peruvian and 16 Chilean regions over the period 2008 - 2015 and, in doing so, relate mine-specific data on extraction intensity to regional economic impacts. The study employs a Spatial Durbin Model (SDM) with heteroskedastic errors to provide a flexible econometric framework to measure the impact of natural resource extraction. The results suggest that mining intensity does not significantly affect regional economic growth in both short-run and medium-run growth models. Popular arguments of the mining industry that the extractive sector would trigger positive impulses for regional economic development cannot be verified. Rather, the findings support narratives that mining regions do not benefit from their wealth in natural resources due to low labour intensity, loose links to local suppliers and profit outflows.Series: Ecological Economic Paper

    A review and comparative assessment of existing approaches to calculate material footprints

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    Effective implementation of resource policies requires consistent and robust indicators. An increasing number of national and international strategies focussing on resource efficiency as a means for reaching a green economy call for such indicators. As supply chains of goods and services are increasingly organised on the global level, comprehensive indica-tors taking into account upstream material flows associated with internationally traded products need to be compiled. Particularly in the last few years, the development of con-sumption-based indicators of material use also termed material footprints has made considerable progress. This paper presents a comprehensive review of existing methodol-ogies to calculate material footprint-type indicators. The three prevailing approaches, i.e. environmentally extended input-output analysis (EE-IOA), coefficient approaches based on process analysis data, and hybrid approaches combing elements of EE-IOA and process analysis are presented, existing models using the different approaches discussed, and advantages and disadvantages of each approach identified. We argue that there is still a strong need for improvement of the specific approaches as well as comparability of re-sults, in order to reduce uncertainties. The paper concludes with recommendations for further development covering methodological, data and institutional aspects

    Review of land flow accounting methods and recommendations for further development

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    Robust land footprint indicators can potentially extend the consumption-based resource use indicator of the German sustainability strategy, which focuses on abiotic resources including fossil fuels, metals, and construction and industrial minerals and decidedly excludes biotic resources. Various approaches exist for quantifying the land embodied in international trade flows and consumption, i.e. the land footprint. These can be classified into a) environmental-economic accounting approaches, applying input-output analysis and tracking supply chains in monetary values, b) physical accounting approaches, using an accounting framework based on data for production, trade and utilization of agricultural and forestry commodities and tracking supply chains in physical units, and c) hybrid accounting, combining elements from both environmental-economic and physical accounting. The results of recent studies vary widely, indicating a lack of robustness and thus hampering their application in policy making. This report provides an in-depth review of the current state of the art in measuring land footprints. We identify differences in available accounting methods and indicate their shortcomings, which are mainly attributable to the product and supply chain coverage and detail, and biases introduced by the use of monetary flows as a proxy for actual physical flows. We offer options and give clear recommendations for the further development of actual and virtual global biomass and land flow accounting methods, particularly highlighting the advantages of hybrid accounting approaches as a framework for the robust and transparent assessment of land footprints associated with global biomass flows

    Unveiling Drivers of Deforestation: Evidence from the Brazilian Amazon

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    Deforestation of the Amazon rainforest is a threat to global climate, biodiversity, and many other ecosystem services. In order to address this threat, an understanding of the drivers of deforestation processes is required. Indirect impacts and determinants that eventually differ across locations and over time are important factors in these processes. These are largely disregarded in applied research and thus in the design of evidence-based policies. In this study, we employ a flexible modelling framework to gain more accurate quantitative insights into the complexities of deforestation phenomena. We investigate the impacts of agriculture in Mato Grosso, Brazil, for the period 2006-2017 and explicitly consider spatial spillovers and varying impacts over time and space. Spillover effects from croplands in the Amazon appear as the major driver of deforestation, with no direct effects from agriculture in later years. This suggests moderate success of the Soy Moratorium and Cattle Agreements, but highlights their inability to address indirect effects. We find that neglect of spatial dynamics and the assumption of homogeneous impacts leads to distorted inference. Researchers need to be aware of the complex and dynamic processes behind deforestation, in order to facilitate effective policy design.Series: Ecological Economic Paper

    The global cropland footprint of the non-food bioeconomy. ZEF - Discussion Papers on Development Policy No. 253

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    A rapidly growing share of global agricultural areas is devoted to the production of biomass for non - food purposes. The derived products include, for example, biofuels, textiles, detergents or c osmetics. Given the far - reaching global implications of an expanding non - food bioeconomy, an assessment of the bioeconomy's resource use from a footprint perspective is urgently needed. We determine the global cropland footprint of non - food products with a hybrid land flow accounting model combining data from the Food and Agriculture Organization and the multi - regional input - output model EXIOBASE. The globally interlinked model covers all cropland areas used for the production of crop - and animal - based non - food commodities for the years from 1995 to 2010. We analyse global patterns of raw material producers, processers and consumers of bio-based non-food products, with a particular focus on the European Union. Results illustrate that the EU is a major processer and the number one consumer region of non-food cropland, despite being only the fifth largest producing region. Two thirds of the cropland required to satisfy EU non-food consumption are located in other world regions, giving rise to a significant depe ndency on imported products and to potential impacts on distant ecosystems. With almost 29% in 2010, oilseed production, used to produce, for example, biofuels, detergents and polymers, represents the dominant share in the EU's non-food cropland footprint. There is also a significant contribution of more traditional non-food biomass uses such as fibre crops (for textiles) and animal hides and skins (for leather products). Our study emphasises the importance of comprehensively assessing the implications of the non-food bioeconomy expansion as envisaged in various policy strategies, such as the Bioeconomy Strategy of the European Commission

    The global cropland footprint of the non-food bioeconomy

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    A rapidly growing share of global agricultural areas is devoted to the production of biomass for non-food purposes. The derived products include, for example, biofuels, textiles, detergents or cosmetics. Given the far-reaching global implications of an expanding non-food bioeconomy, an assessment of the bioeconomy’s resource use from a footprint perspective is urgently needed. We determine the global cropland footprint of non-food products with a hybrid land flow accounting model combining data from the Food and Agriculture Organization and the multi-regional input-output model EXIOBASE. The globally interlinked model covers all cropland areas used for the production of crop- and animal-based non-food commodities for the years from 1995 to 2010. We analyse global patterns of raw material producers, processers and consumers of bio-based non-food products, with a particular focus on the European Union. Results illustrate that the EU is a major processer and the number one consumer region of non-food cropland, despite being only the fifth largest producing region. Two thirds of the cropland required to satisfy EU non-food consumption are located in other world regions, giving rise to a significant dependency on imported products and to potential impacts on distant ecosystems. With almost 29% in 2010, oilseed production, used to produce, for example, biofuels, detergents and polymers, represents the dominant share in the EU’s non-food cropland footprint. There is also a significant contribution of more traditional non-food biomass uses such as fibre crops (for textiles) and animal hides and skins (for leather products). Our study emphasises the importance of comprehensively assessing the implications of the non-food bioeconomy expansion as envisaged in various policy strategies, such as the Bioeconomy Strategy of the European Commission

    Spatially explicit assessment of water embodied in European trade: A product-level multi-regional input-output analysis

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    Responsible water management in an era of globalised supply chains needs to consider both local and regional water balances and international trade. In this paper, we assess the water footprints of total final demand in the EU-27 at a very detailed product level and spatial scale - an important step towards informed water policy. We apply the multi-regional input-output (MRIO) model EXIOBASE, including water data, to track the distribution of water use along product supply chains within and across countries. This enables the first spatially-explicit MRIO analysis of water embodied in Europe's external trade for almost 11,000 watersheds world-wide, tracing indirect ("virtual") water consumption in one country back to those watersheds where the water was actually extracted. We show that the EU-27 indirectly imports large quantities of blue and green water via international trade of products, most notably processed crop products, and these imports far exceed the water used from domestic sources. The Indus, Danube and Mississippi watersheds are the largest individual contributors to the EU-27's final water consumption, which causes large environmental impacts due to water scarcity in both the Indus and Mississippi watersheds. We conclude by sketching out policy options to ensure that sustainable water management within and outside European borders is not compromised by European consumption
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