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Lithostratigraphical and biostratigraphical investigation of coastal marshes along the Atlantic coast of the Outer Hebrides from Lewis in the north to Barra in the south discloses inland-tapering sand units within marshland areas. The inland extent of each sand unit has been radiometrically dated and the units have been collectively interpreted as a proxy for past coastal storminess. The data appear to indicate that for the study sites investigated, the majority of the sand units were produced during episodes of climate deterioration both prior to and after the well-known period of Medieval warmth (MWP). Many were produced after ca. AD 1400. It is argued that the episodes of sand blow indicated by the deposits may reflect periods of increased cyclogenesis in the Atlantic associated with increased sea ice cover and an increase in the thermal gradient across the North Atlantic region.  相似文献   
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Although evidence for Quaternary environmental changes in the Arabian Peninsula is now growing, research has mostly been conducted in the United Arab Emirates (UAE) and in the Sultanate of Oman. There have been virtually no recent studies in Saudi Arabia, especially in the central region such as around Al‐Quwaiayh. In this area there are a series of outwash plains developed along the eastern edge of the Arabian Shield that formed in the late Quaternary. Four sedimentary sections, which are representative of the deposits that have accumulated, have been studied and five luminescence ages obtained. These are the first luminescence ages acquired from Quaternary sediments in central Saudi Arabia. The preserved fluvial deposits in the study area have formed during humid events at ca. 54 ka, ca. 39 ka and ca. 0.8 ka. In more recent times aeolian sands have been encroaching on to the distal parts of the outwash plains. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
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The Tanga Coastal Zone Conservation and Development Programme, initiated in 1994, was among the first such projects to make livelihoods improvement a key objective, and to use a community-based approach. It developed an approach to coastal management planning that is broadly satisfactory to both communities and the government. Six fisheries management areas and two mangrove management areas were established. Institutional arrangements for the collaborative approach were strengthened and community leaders and local government officers were trained in a range of relevant skills. A coastal environmental education programme for primary schools involved several thousand schoolchildren, and a gender programme built the confidence of women. Implementation of the management measures was noticeably harder than planning, particularly elimination of destructive fishing methods. Fishers and coastal communities now however have a much greater involvement in, and understanding of, coastal management and consequently a greater sense of ownership.  相似文献   
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