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Colombo, Sri Lanka

Jennings R.P.,University of Oxford | Shipton C.,University of Queensland | Breeze P.,Kings College London | Cuthbertson P.,University of Oxford | And 11 more authors.
Quaternary International | Year: 2015

The interpretation of Acheulean landscape use through the analysis of artefact distributions over a range of environmental settings is vital for understanding early hominin behaviour. Such approaches have been successfully applied in areas such as East Africa and South Africa, where long-term and sustained archaeological research has led to the development of robust environmental frameworks within which to analyse hominin land-use patterns. Much less is known about Acheulean hominin behaviour in the Arabian Peninsula, which is increasingly being recognised as an important area for studying early hominin dispersals and adaptations to new environments. To address this lacuna, we have undertaken the first multi-scale systematic survey of Acheulean occupation evidence at Dawadmi, in the centre of the Arabian Peninsula. Specifically, we carried out systematic transect surveys over a large andesite dyke at Saffaqah, on which the majority of 26 known Acheulean sites are associated, as well as across narrow drainage channels, desert pavements and hills located within 5 km of the dyke. Survey transects also crossed neighbouring dykes and adjacent landscape units with a 25 × 20 km area. Our surveys at Saffaqah have led to the discovery of 14 new Acheulean sites. Initial lithic analyses reveal differences between sites in terms of typology, but further work on the assemblages is required to determine if these differences are behavioural or a product of post depositional processes. A broad regional survey was undertaken to identify the full extent of Acheulean activity around Dawadmi. This led to the discovery of a further 22 sites. There is a strong correspondence between Acheulean sites and fine-grained andesite dykes, which were major lithic raw material sources. No Acheulean sites in the study area were found away from dykes or their adjacent landscape units. Based on dyke distributions, the geographic range of Acheulean activity is estimated to be 100 × 55 km, making Dawadmi one of the largest Acheulean landscapes in the world. © 2015 Elsevier Ltd and INQUA.

Vitharana P.,Sir Marcus Fernando Mawatha | Narayana M.,University of Moratuwa | Perera K.U.C.,Open University of Sri Lanka | Perera S.,Sir Marcus Fernando Mawatha
MERCon 2015 - Moratuwa Engineering Research Conference | Year: 2015

Water diversion mechanisms are commonly used in the irrigation systems and this concept is older than tank (reservoir) systems in Sri Lanka. At present, for water diversions in the wet zone anicuts are constructed by using lifting type gates. Anicuts are used to maintain required water level in the upstream by releasing only the excess water to downstream. In the lifting gate, water is allowed to flow from the bottom and this causes high erosion in the canal. The thrust force due to water pressure on the lifting gate makes it difficult to operate the system and then controlling the system is a complex task. This paper describes the construction and operation of newly introduced flap gates and issues related to lifting gate which are presently used for diversion process. In this analysis, conceptual design of a flap gate with compressive arc type wall plate is proposed to minimize use of construction materials. In the proposed system, height of the anicut could be changed from the top and then the water level in the upstream is not varied much when compared with lifting gates for varying flows in the cannel. According to the practical experiences from implemented proposed systems, controlling of the system is much easier compared to the conventional system. © 2015 IEEE.

Roberts P.,University of Oxford | Perera N.,Postgraduate Institute of Archaeology | Wedage O.,Sir Marcus Fernando Mawatha | Deraniyagala S.,Sir Marcus Fernando Mawatha | And 5 more authors.
Science | Year: 2015

Human occupation of tropical rainforest habitats is thought to be a mainly Holocene phenomenon. Although archaeological and paleoenvironmental data have hinted at pre-Holocene rainforest foraging, earlier human reliance on rainforest resources has not been shown directly. We applied stable carbon and oxygen isotope analysis to human and faunal tooth enamel from four late Pleistocene-to-Holocene archaeological sites in Sri Lanka. The results show that human foragers relied primarily on rainforest resources from at least ∼20,000 years ago, with a distinct preference for semi-open rainforest and rain forest edges. Homo sapiens' relationship with the tropical rainforests of South Asia is therefore long-standing, a conclusion that indicates the time-depth of anthropogenic reliance and influence on these habitats. © 2015, American Association for the Advancement of Science. All rights reserved.

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