35 research outputs found

    Patterns of tree cover loss along the Indonesia-Malaysia border on Borneo

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    Borneo Island is experiencing rapid tree-cover loss. This loss has been quantified for the Indonesian part of the island at Landsat spatial resolution, but no recent study exists that extends across the border into Malaysia. This research focused on quantifying patterns of tree-cover loss in the IndonesiaMalaysia border zone on Borneo. The methods used for quantifying 20002010 tree-cover loss within 20 km on either side of the border are an internally consistent mapping algorithm used on Landsat imagery and a local indicator of spatial autocorrelation to quantify the concentration of loss. Within the 20 km zone on either side of the border, tree-cover loss rates in lowlands were high in the two countries (19.8% and 14.4%, in Indonesia and Malaysia, respectively), but rates in the Malaysian uplands were an order of magnitude higher than in the Indonesian uplands (2.95% and 0.25%, respectively). Clusters of tree-cover loss in the Malaysian uplands were considerably larger than in the Indonesian uplands

    Quantifying forest cover loss in Democratic Republic of the Congo, 2000-2010, with Landsat ETM+ data

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    Forest cover and forest cover loss for the last decade, 2000â2010, have been quantified for the Democratic Republic of the Congo (DRC) using Landsat time-series data set. This was made possible via an exhaustive mining of the Landsat Enhanced Thematic Mapper Plus (ETM+) archive. A total of 8881 images were processed to create multi-temporal image metrics resulting in 99.6% of the DRC land area covered by cloud-free Landsat observations. To facilitate image compositing, a top-of-atmosphere (TOA) reflectance calibration and image normalization using Moderate Resolution Imaging Spectroradiometer (MODIS) top of canopy (TOC) reflectance data sets were performed. Mapping and change detection was implemented using a classification tree algorithm. The national year 2000 forest cover was estimated to be 159,529.2 thousand hectares, with gross forest cover loss for the last decade totaling 2.3% of forest area. Forest cover loss area increased by 13.8% between the 2000â2005 and 2005â2010 intervals, with the greatest increase occurring within primary humid tropical forests. Forest loss intensity was distributed unevenly and associated with areas of high population density and mining activity. While forest cover loss is comparatively low in protected areas and priority conservation landscapes compared to forests outside of such areas, gross forest cover loss for all nature protection areas increased by 64% over the 2000 to 2005 and 2005 to 2010 intervals

    Devastating Decline of Forest Elephants in Central Africa.

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    African forest elephants– taxonomically and functionally unique–are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002–2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced

    Biomass Resources: Agriculture

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    Bioenergy is the single largest source of renewable energy in the European Union (EU-28); of this, 14% was produced from agricultural feedstocks in 2012. This chapter provides an overview of the current use (for bioenergy) and future potential of agricultural feedstocks for (amongst others) biorefinery purposes in the European Union. The main application of these feedstocks is currently the production of biofuels for road transport. Biodiesel makes up 80% of the European biofuel production, mainly from rapeseed oil, and the remaining part is bioethanol from wheat and sugar beet. Dedicated woody and grassy crops (mainly miscanthus and switchgrass) are currently only used in very small quantities for heat and electricity generation. There is great potential for primary agricultural residues (mainly straw) but currently only part of this is for heat and electricity generation. Agricultural land currently in use for energy crop cultivation in the EU-28 is 4.4 Mio ha, although the land area technically available in 2030 is estimated to be 16–43 Mio ha, or 15–40% of the current arable land in the EU-28. There is, however, great uncertainty on the location and quality of that land. It is expected that woody and grassy crops together with primary agricultural residues should become more important as agricultural feedstocks

    Quantifying Uncertainty for Estimates Derived from Error Matrices in Land Cover Mapping Applications:The Case for a Bayesian Approach

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    The use of land cover mappings built using remotely sensed imagery data has become increasingly popular in recent years. However, these mappings are ultimately only models. Consequently, it is vital for one to be able to assess and verify the quality of a mapping and quantify uncertainty for any estimates that are derived from them in a reliable manner. For this, the use of validation sets and error matrices is a long standard practice in land cover mapping applications. In this paper, we review current state of the art methods for quantifying uncertainty for estimates obtained from error matrices in a land cover mapping context. Specifically, we review methods based on their transparency, generalisability, suitability when stratified sampling and suitability in low count situations. This is done with the use of a third-party case study to act as a motivating and demonstrative example throughout the paper. The main finding of this paper is there is a major issue of transparency for methods that quantify uncertainty in terms of confidence intervals (frequentist methods). This is primarily because of the difficulty of analysing nominal coverages in common situations. Effectively, this leaves one without the necessary tools to know when a frequentist method is reliable in all but a few niche situations. The paper then discusses how a Bayesian approach may be better suited as a default method for uncertainty quantification when judged by our criteria
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