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Digital analysis of Landsat data is applied to up-dating land cover maps for the Goondiwindi district of southern, inland Queensland. The imagery was paired with climax cover maps obtained from land systems reports with analysis conducted separately for each of three climax cover types (open forest, woodland and open woodland). Computer classification using this approach produced readily interpreted and reliable results. This work demonstrates that Landsat can be used in conjunction with existing, land systems derived maps to produce data that combine the advantages of two approaches to environmental survey, the former being based on current land cover/land use and the latter on the original environment and its land use potential.  相似文献   
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A Roman wreck, named Plemmirio B[1]i, lies on the rocky talus below the southern cliffs of Capo Murro di Porco, near Costa Bianca del Plemmirio (Penisola della Maddalena), prov. Siracusa, Sicily. The cargo of amphoras and iron bars, relatively well-preserved, is situated between 22 m and 47 m depth. Following brief examinations in 1974–1982, a University of Bristol expedition spent four weeks surveying the site in July-August 1983[2] This paper presents an interim summary of these campaigns; a comprehensive report will be published after completion of excavations at the site[3]. The archaeological deposit at Plemmirio B is characterized by concentrations of fragmented amphoras. There is no direct evidence for the structure of the ship, much of which may have disintegrated during the initial wreck process, but study of the artefact distribution suggests a vessel of fairly large capacity. The amphora consignment (which may have numbered no more than 200) comprised cylindrical African containers, 80% of which were form Africana 2A and 20% Africana 1[4] w. The Africana 2A amphoras had internal resinous linings, and so may have contained a fish product rather than olive oil. Other amphoras exposed on the site were at least one Mauretanian Dressel 30 (Keay type 1) and two possibly intrusive amphoras of unclassified types. Ferrous concretions contained voids (hollow casts) which may once have been about 39 wrought iron bars, of two distinctive shapes. These, and several other concretions of unidentified forms, may represent a consignment of iron originally weighing approximately one tonne. Other finds from the wreck are two cooking pots, a small bowl or cup, a sounding lead, three fragments of tegula rooftiles, and two small stone blocks. One of the cooking pots confirms a date for the wreck based on the amphora association of circa AD 180–250, most likely in the first decade of the 3rd century. The amphora assemblage belongs to an important phase of commerce from North Africa represented by at least 20 known wreck cargoes; however, few of these sites have been scientifically recorded or are as closely dated as Plemmirio B, and the diversity of container types and cargo consignments on this wreck is of particular interest.  相似文献   
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A significant metamorphosis of channel form occurred on the lower Macdonald River between 1949 and 1955; width and width-depth ratio increased and depth, sinuosity and weighted mean per cent silt-clay in the channel perimeter decreased. The channel has remained unstable since 1955, exhibiting frequent variations in bed elevation and a recent period of minor channel contraction followed by slight enlargement. Since 1946 there has been an increase in summer and annual rainfall and an abrupt, upward shift of the annual series flood frequency curve. As a result an increased proportion of the total sediment load of the river is now being transported as bed-material load. The change in sediment load is a result of greater stream competence and the consequent reworking of sandy sediment temporarily stored within the channel as benches. The observed channel changes are a quasi-adjustment to the increased flood and bed-material load discharges.  相似文献   
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Discovery of the uses and later the invention of fire-making are fundamental to humanity. Following reports over the last decade of traces of fire found on Lower Pleistocene archaeological sites in eastern Africa, the dating of the control of fire by hominids has become a controversial issue. In this paper we critically review the contexts and, in the light of a battery of archaeometric techniques, the nature of reported instances of fire from Koobi Fora and Chesowanja in Kenya, and from Gadeb and the Middle Awash in Ethiopia. We conclude with a discussion of the roles fire may have played in the lifeways of early Pleistocene savanna-living hominids.
Résumé La découverte des usages du feu et ensuite de sa préparation est fondamentale pour l'humanité. Suite à des rapports au cours de la dernière décennie signalant des traces de feu relevées dans des sites archéologiques du Pléistocène inférieur dans l'est de l'Afrique, la datation du contrôle du feu par les hominiens est devenu une source de controverse. Dans cet article, nous révisons d'un oeil critique les contextes et la nature des cas de feu signalés à Koobi Fora et à Chesowanja au Kenya, et à Gadeb et dans l'Awash moyen en Éthiopie, à la lumière d'une suite de techniques archéometriques. Suit en conclusion une discussion sur les rôles qu'aurait pu jouer le feu dans les modes de vie des hominiens vivant dans les savannes du Pléistocène inférieur.
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