40 research outputs found

    A Land System representation for global assessments and land-use modeling

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    Current global scale land-change models used for integrated assessments and climate modeling are based on classifications of land cover. However, land-use management intensity and livestock keeping are also important aspects of land use, and are an integrated part of land systems. This article aims to classify, map, and to characterize Land Systems (LS) at a global scale and analyze the spatial determinants of these systems. Besides proposing such a classification, the article tests if global assessments can be based on globally uniform allocation rules. Land cover, livestock, and agricultural intensity data are used to map LS using a hierarchical classification method. Logistic regressions are used to analyze variation in spatial determinants of LS. The analysis of the spatial determinants of LS indicates strong associations between LS and a range of socioeconomic and biophysical indicators of human-environment interactions. The set of identified spatial determinants of a LS differs among regions and scales, especially for (mosaic) cropland systems, grassland systems with livestock, and settlements. (Semi-)Natural LS have more similar spatial determinants across regions and scales. Using LS in global models is expected to result in a more accurate representation of land use capturing important aspects of land systems and land architecture: the variation in land cover and the link between land-use intensity and landscape composition. Because the set of most important spatial determinants of LS varies among regions and scales, land-change models that include the human drivers of land change are best parameterized at sub-global level, where similar biophysical, socioeconomic and cultural conditions prevail in the specific regions. © 2012 Blackwell Publishing Ltd

    Co-evolution of density and topology in a simple model of city formation

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    We study the influence that population density and the road network have on each others' growth and evolution. We use a simple model of formation and evolution of city roads which reproduces the most important empirical features of street networks in cities. Within this framework, we explicitely introduce the topology of the road network and analyze how it evolves and interact with the evolution of population density. We show that accessibility issues -pushing individuals to get closer to high centrality nodes- lead to high density regions and the appearance of densely populated centers. In particular, this model reproduces the empirical fact that the density profile decreases exponentially from a core district. In this simplified model, the size of the core district depends on the relative importance of transportation and rent costs.Comment: 13 pages, 13 figure

    Core-Periphery Model

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    Core-periphery imbalances and regional disparities figure prominently on the agenda of several disciplines, which result from their enormous impact on economic and social development around the world. In sociology, international relations, and economics, this concept is crucial in explanations of economic exchange. There are few countries that play a dominant role in world trade, while most countries have a secondary or even a tertiary position in world trade. Moreover, when we are discussing global, continental, regional, and national economies, we can present regions and even smaller territorial units which have higher wages than some underdeveloped areas within the same larger area in focus. Such regional inequalities and injustices are the main themes of the core-periphery model, which focuses on tendencies of economic activities to concentrate around some pivotal points. It seeks to explain the spatial inequalities or imbalances observable on all levels or scales by highlighting the role of horizontal and vertical relations between various entities from the level of towns and cities to the global scale. The existence of a core-periphery structure implies that in the spatial dimension, the socioeconomic development is usually uneven. From such a geographical perspective, the regions known as the "core" are advanced in various areas, while other regions described as the "periphery" serve as a social, economic, and political backstages, backyards, and supply sources or - in some cases - are even subject to degradation and decline. Furthermore, the level of development has a negative correlation with distance from the core. The economies of the states that have gone through various stages of development at the earliest and with the fastest pace have become wealthy core regions and growth poles. Those countries and regions where these processes have been slower become or remain the poor periphery

    The spatial structure of lithic landscapes : the late holocene record of east-central Argentina as a case study

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    Fil: Barrientos, Gustavo. División Antropología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Catella, Luciana. División Arqueología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Oliva, Fernando. Centro Estudios Arqueológicos Regionales. Facultad de Humanidades y Artes. Universidad Nacional de Rosario; Argentin

    Ziber, Nikolaj Ivanovich (1844–1888)

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