Impacts of River Regulation on the Terminal Lakes and Mouth of the River Murray,South Australia

The River Murray is a highly regulated, low gradient stream. Prior to barrage construction near the Murray Mouth saline water was present sporadically far upstream. Barrage completion by 1940 has had geo-morphic and ecological impacts. Estuarine Lakes Albert and Alexandrina became permanent freshwater bodies with elevated water levels. Exposed lake margins have eroded by up to 10 m yr', whereas along sheltered shorelines, sedimentation has accompanied reed growth. Upstream weirs have inhibited coarse sediment from reaching the lakes. In the Goolwa Channel, sedimentation changed from bioclas-tic sands to muds, accumulating at up to 4.5 mm yr' over the past 50 years. Regulation has also transformed a migrating flood tidal delta at the Murray Mouth into a permanently vegetated island.     

The Herbert River,Queensland, Tropical Australia: Community Perception and River Management

There is a widespread perception amongst the community of Ingham and surrounding areas that the Herbert River in tropical Queensland has aggraded since the time of European settlement. Yet this perception is not supported by such evidence as historical accounts of the river and river trade, changes at the Ingham gauging station since 1940 and comparison of channel cross-sections surveyed since 1968. No reason has been identified for this divergence, but experience elsewhere teaches us that ignoring local perception is likely to result in an incomplete understanding of environmental issues. Unless the challenge of reconciling popular perception and deductive interpretation of the evidence is met, the potential for conflict will remain. Community proposals for strategies will struggle for support from the ‘rationalists’ and the community will oppose ‘rational’ strategies if they are not seen to be addressing the ‘real’ problems.     

渝宜段川江水系的历史分布与变迁

重庆至湖北宜昌段川江水系的分布与变迁对长江上游航运、沿岸聚落环境等社会经济均有一定的影响,也是现今三峡库区建设需要认真考察的课题。文章着重对该区域内主要水系的历史名称、河道变化进行考证与辨识,并相应地分析部分河流在航运、灾害方面发生变化的自然因素和人文因素。     

Akko 1 shipwreck: the effect of cannon fire on the wooden hull

The Akko 1 shipwreck was discovered inside the harbour of the old walled city of Akko (Acre, St. Jean d'Acre, Akka), Israel. The ship's hull was built mainly of oak, with closely-set framing timbers that created a solid side. The shipwreck was apparently a result of the naval bombardment of the town in 1840.     

New insights regarding the Akko 1 shipwreck: a metallurgic and petrographic investigation of the cannonballs

The Akko 1 shipwreck constitutes the remains of a small Mediterranean naval vessel, discovered in Akko harbour, Israel, and excavated over three seasons between 2006 and 2008. Among the finds at the shipwreck site were eleven cannonballs. Two of them, a 9-pdr and a 24-pdr, were retrieved and studied using metallurgical and petrographic methods. The examination of the cast-iron was performed with optical microscopy, SEM–EDS, XRF and microhardness tests. The remains of the casting sand from within the voids in both cannonballs were studied by petrography. Combined with the archaeological evidence and the historical background, the metallurgical and petrographic testing may suggest that Akko 1 was a warship or an auxiliary naval vessel of similar size to, or slightly smaller than, sixth rate, and was in Akko harbour circa 1840.     

The 4th-century B.C. shipwreck at Mazotos,Cyprus: New techniques and methodologies in the 3D mapping of shipwreck excavations

Abstract

Well preserved ancient shipwrecks are rare in the archaeological record, but when discovered, they can provide valuable information on a wide range of research issues if analyzed and documented properly. In this paper we discuss the significance, potential, and constraints of mapping methods applied during the underwater excavation of shipwreck sites with special emphasis on stratigraphy, documentation of finds, and reconstruction of site formation processes. As a case study, we present the digital photogrammetry and computer vision software programs used in the excavation of the 4th-century b.c. shipwreck at Mazotos, Cyprus. Our goal is to develop a targeted documentation and mapping method of ongoing shipwreck excavations so that others can address complex research questions concerning this unique discipline of archaeology.     

Processes and patterns of flow,erosion, and deposition at shipwreck sites: a computational fluid dynamic simulation

Shipwreck sites are open systems, allowing the exchange of material and energy across system boundaries. Physical processes dominate site formation at fully submerged wreck sites, and in turn influence chemical and biological processes at many stages of site formation. Scouring presents a fundamental yet poorly understood threat to wreck sites, and the processes and patterns of erosion and deposition of sediments and artefacts at wreck sites are poorly understood. Laboratory and field-based experiments to study these phenomena are time-consuming and expensive. In this study, open-source computational fluid dynamic (CFD) simulations are used to model the processes and patterns of flow, erosion, and deposition at fully submerged wreck sites. Simulations successfully capture changes in the flow regime in the environment of the wreck as a function of incidence angle, including flow contraction, the generation of horseshoe vortices in front of the wreck, the formation of lee-wake vortices behind the structure, and increased turbulence and shear stress in the lee of the wreck site. CFD simulations demonstrate that horseshoe vortices control scour on the upstream face of structure but play a minimal role in scouring on the lee side. Lee-wake vortices dominate behind the structure, with low-pressure zones in the lee of the wreck capturing flow. The amplification and reduction of wall shear stress and turbulent kinetic energy in the lee of the vessel form distinctive patterns in relation to flow direction, with areas of amplified and reduced wall shear stress and turbulent kinetic energy demonstrating excellent spatial correlation with erosional and depositional patterns developed at real-world wreck sites.     

葡萄牙人首航东方的历史性创举——纪念瓦斯科·达·伽马首航印度500周年(1498～1998年)

１４９８年是东西方关系史上划时代的界标。葡萄牙人首航印度的成功象征着东西方文明汇合的历史性起点。今年正值纪念这个伟大日子５００周年的时刻,我很荣幸地撰写了本文,奉献给这次在巴黎举行的具有重大历史意义的国际学术讨论会。一历史呼唤东方新航路欧亚非三洲同处...     

Phosphatic fauna of the Early Cambrian Todd River Dolomite,Amadeus Basin,central Australia

Ten species of phosphatic or phosphatised fossils are described from the Early Cambrian Todd River Dolomite of the Amadeus Basin in central Australia. The tannuolinid genus Micrina nov. is erected to include Platyceras etheridgei Tate 1892. The family Kennardiidae nov. is erected to include phosphatic organisms having three distinct forms of mitral sclerite. Assigned to this family are Kennardia reticulata gen. et sp. nov. and tentatively Dailyatia ajaxBischoff. Other phosphatic problematica are Paterimitra pyramidalis gen. et sp. nov., Eccentrotheca cf. kanesia Landing, Nowlan & Fletcher. Also described are phosphatised Chancelloria sp., Lenastella sp. and Pelagiella sp. and the phosphatic inarticulate brachiopods Askepasma toddensegen. et sp. nov., Edreja aff. distincta Koneva and ?Lingulella sp. Two species of tubular problematica are illustrated but not discussed in detail.     

Bai Jiao 1—the excavation of a Song Dynasty shipwreck in the Dinghai area, Fujian Province, China, 1995

The ships that sail the Southern Sea and south of it are like houses. When their sails are spread they are like great clouds in the sky… The big ship with its heavy cargo has naught to fear of the great waves, but in shallow water it comes to grief (cited in Guy, 1992: 18).     

Landscape Methods Abroad (with reference to land resource studies of the United States and Australia)

Although landscape research has not been set apart formally as a distinctive branch of geography in the West, the methods used in certain research programs in the United States and in Australia come close to the integrated areal approach to the study of the physical environment characteristic of Soviet landscape science. In the United States, landscape-like methods are used by the Soil Survey staff of the Department of Agriculture in its soil surveys of counties. In Australia, the landscape approach is used by the Division of Land Research of the Commonwealth Scientific and Industrial Research Organization in its reports on Australia's land systems.     

Perilous shipwreck, misery and unhappiness: the British military at Tristan da Cunha, 1816–1817

After losing the Battle of Waterloo in 1815, Napoleon was exiled to St Helena. As part of the arrangements to keep him secure, the British annexed the island of Tristan da Cunha to deny its possible use to French rescue forces. The military remained on the island for fifteen months, an unpleasant experience, especially given the loss of 55 people in the wreck of H.M.S. Julia in 1817. Using evidence from holdings in the National Maritime Museum in Greenwich, this paper studies the experiences of the British on the island during 1816 and 1817, illuminating the chaotic military operation and also the difficulties of habitation on Tristan da Cunha. However, the present population of the island traces its origin back to one of the garrison who remained there after 1817.