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61.
62.
Leaky aquifers constitute complicated hydrological structures, whose inclusion in numerical models of hydrological systems is difficult, because of their three-dimensional nature. Methods for treating such systems can be classified as fully three-dimensional and quasi-three-dimensional. The latter have clear numerical advantages when applicable. In this paper a critical discussion of existing quasi-three-dimensional models is presented.  相似文献   
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We present high angular resolution MERLIN observations of the 18-cm OH maser and continuum emission associated with the active core of the ultraluminous infrared galaxy Markarian 273. The continuum emission comes from three distinct regions in the central arcsecond of the galaxy. The brightest region of emission has a double-peaked structure which is spatially coincident with similar structures observed at 6 cm and 2.2 μm. The peak of the OH maser emission is spatially coincident with the peak in the continuum. For the first time the maser emission is spatially resolved, allowing us to measure the gas motion within the central 100 pc of the galaxy. Maser emission is found in both the 1665- and 1667-MHz lines, with no systematic offset found in the spatial locations of the two lines. The brighter component of the maser emission shows ordered motion and is aligned along the axis of the double-peaked structure in the brightest continuum region. The gas motion enables us to estimate the central mass density to be 850±50 M pc−3, which corresponds to a total mass of ≈1.5×108 M.  相似文献   
65.
E. M. Yates 《GeoJournal》1992,26(3):265-275
In the first section concepts relating to the ownership of land, as voiced by various thinkers from Plato and Aristotle to Locke, Proudhon and Marx, are discussed. In the second section it is shown, that despite the high moral tone of the theorists, in practice land was acquired by theft, the theft perhaps followed by some retrospective attempts to achieve legality. Land was also expropriated on a large scale to be used as a counter in the struggle between the power groupa within the state. In the third section the present day relevance of estate ownership is briefly examined, with reference to political power and to environmental conservation. It is suggested that ideally there should be a return to a leasehold system, in Proudhon's terms possession rather than ownership, land leased from the community and forfeited if environmental damage is inflicted. There should be limit to the upward size of estates in order to limit the political advantages that accrue to families holding large areas of land. For these reforms to be effective and enormous enlargement of democratic processes is required, accompanied by a reduction in power of the central authorities, and by an increase in the financial and intellectual investment in education.  相似文献   
66.
Accounts that address the governance of adaptation are increasingly exploring the ways in which the institutional context can both enable and constrain effective and equal adaptation. This paper contributes to such a growing field by providing empirical evidence derived from participatory field research in the Nepali districts of Chitwan and Nawalparasi in 2010. The results support previous arguments that emphasise the need to address the multi-scalar context of adaptation as a governance issue associated with individual and collective deliberative action (or inaction). Institution analysis identifies the ways in which networks of powerful and well-connected political actors are able to control adaptation projects, flows of knowledge and information, and the ways in which institutions and organisations intervene in response to livelihood needs. This control is under-pinned by an unequal scalar politics that constructs and reproduces particular local adaptation needs at multiple governance scales at once. Many existing tools and frameworks for assessing the institutional elements of adaptation are unable to grapple with these factors systematically. The paper concludes with a call for further attention to forms of scalar politics in the governance of adaptation so that we might be able to more effectively theorise up from local complexity without glossing over inherent power relations, social inequalities, and institutional constraints.  相似文献   
67.
U.S. Country Studies supported analyses of climate change impacts on water resources have been completed or are underway in the following Central and Eastern European nations: Czech Republic, Slovakia, Poland, Romania, Estonia, Russian Federation, and the Ukraine. Climate change impacts on the hydrologic resources of these countries is being performed at the river basin scale using monthly water balance models using GCM-based climate scenarios. The authors have performed a regional analysis of climate change impacts on the Hydrologic Resources of Europe using the Turc Annual Model. The regional analysis was done with GIS methodolgies using regional climate databases. The regional results were compared to the U.S. Country Studies hydrologic assessmnent results to validiate the use of this simplified methodolgy for making regional climate change assessment. Results from three countries showed acceptable performace of the annual approach . Using GCM-based climate scenarios regional analysis of potential climate change impacts on the hydrologic resources of Europe was conducted and national and regional results are presented.  相似文献   
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We present MERLIN observations of OH and H2O masers in the circumstellar envelope of S Per. The results are consistent with a model of a thick shell of H2O masers in a region which is still accelerating.  相似文献   
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Aotearoa New Zealand is at a critical juncture in reducing and managing organic waste. Research has highlighted the significant proportion of organic waste sent to landfills and associated adverse effects such as greenhouse gas emissions and loss of valuable organic matter. There is current debate about what practices and infrastructure to invest in to better manage and use organic waste. We highlight the diversity of existing organic waste practices and infrastructures, focusing on Auckland, Wellington and Christchurch. We show how debates about organic waste practices and infrastructure connect across three themes: waste subjectivities, collective action in place and language.  相似文献   
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