Vol. 144, No. 1 · Research article Characterisation of the Rota Wewa DIE ERDE Journal of the tank cascade system in the vicinity Geographical Society of Berlin of Anuradhapura, Sri Lanka Brigitta Schütt1, Wiebke Bebermeier1, Julia Meister1, Chandana Rohana Withanachchi2 1 Freie Universität Berlin, Department of Earth Sciences, Physical Geography, Malteserstr. 74-100, 12249 Berlin, Germany, brigitta.schuett@fu- berlin.de,
[email protected],
[email protected] 2 Department of Humanities, Archaeology and Heritage Management, Rajarata University, Mihintale, Sri Lanka,
[email protected] Manuscript submitted: 2 October 2011 / Accepted for publication: 5 January 2012 / Published online: 2 September 2013 Abstract A complex and sustainable watershed management strategy was implemented in Sri Lanka during the ancient Anuradhapura period, from the 5th century BC to the 11th century AD. Like modern watershed management strategies, it focused on flood prevention, soil erosion control, water quality control and water storage for ir- rigation. Tank cascade systems were the key element of these ancient watershed management installations. The wewas investigated were constructed in valleys characterised by fluvial accumulation. Sedimentologi- cal analyses of these tank cascade systems show that a precise age determination and the reconstruction of sediment and water fluxes as triggered by human-environment interactions are difficult. This is caused by the shallow character of the wewas leading to the steady redeposition of the tank sediments by wave motions dur- ing the wet season and agricultural use of the desiccated wewas during the dry season. Beyond, the sediments analysed allow to distinguish between the weathered parent bedrock and the overlying sediments.