Abstract:
Beside a large number of ancient tunnels in long-distance water conveyance systems toancient cities in Turkiye, five peculiar closed conduits, through which almost the entire discharge of water courses were flowing, are investigated. These are the Cevlik (Seleucia Pieria) tunnel inHatay province; vaulted structures covering the river bed in Bergama (Pergamon), in Sultanhisar(Nysa), in Acarlar near Ephesus (all four are leading examples of largest closed conduits from Roman times in the world); and the Bezirgan tunnel east of Kalkan, being an interesting example of emissary conduits draining the floods of closed basins. The hydraulic capacities of these conduits are determined; their corresponding flood return periods are estimated by four synthetic flood hydrograph methods. However, it was not possible to deduce any generalized conclusion based on the comparison of these results.