The Water Supply of Byzantine Constantinople is one of the most outstanding achievements of hydraulic engineering from the Roman world. Working entirely as a gravity-fed system, this infrastructure relied on hundreds of kilometres of masonry channels, winding along the hills of Turkish Thrace and carrying water to Constantinople across different watersheds. The Water Supply was built in two main phases: the first in the mid-fourth century, following the foundation of Constantinople in 330 AD; and the second in the early fifth century. It is not clear whether the aqueducts from these two phases worked independently or as a single system, yet the scale of this would have been colossal, reaching lengths of 450 km between the two aqueducts. However, a full and close understanding of its hydraulic design and function has until now been missing. As such, this investigation aims to: (1) establish a clear route for the aqueducts, both in terms of length and gradient (mapping); (2) determine likely volumes of water entering the system at the various intakes (hydrology); and (3) evaluate its hydraulic behaviour and flow characteristics (hydraulics). While previous work on similar Roman aqueducts yielded only estimates of maximum capacity, this work delves into the engineering of the ancient infrastructure to provide a more realistic assessment of theWater Supply discharge to the City. The physical configuration of the aqueducts is reinterpreted based on the latest archaeological records comprising Global Positioning System (GPS) measurements and field observations, and validated against modern satellite terrain data in a Geographic Information System (GIS). Refined estimates of length and gradient are proposed, along with a reassessment of all channel observations, bridges and tunnels along the system. It is found that the total length of the aqueducts would have been around 426 km if they operated as a single system, and up to 565 km if they continued in parallel all the way to Constantinople; the gradient of the system would have been well below 0.1% throughout, decreasing from upstream to downstream, with steeper slopes only at the intakes. To estimate reasoned inflow conditions for the Water Supply intakes at the time of its operation, modern spring flow records are investigated, and climatic changes from the Early Byzantine period are studied by means of Macrophysical Climate Modelling (MCM). Monthly and daily resolutions are addressed: monthly inflow data can capture the extent of the seasonal variations that may have occurred at the springs, accounting for karst hydrogeology; daily inflow data allows the study of flow attenuation in the Water Supply in the short term. Simplified models and engineering judgement are employed to recreate monthly and daily inflow series from limited modern data for karstic springs and weather stations in Thrace. The results from GIS mapping, combined with the proposed inflow scenarios, are used to develop open-channel flow modelling of the Water Supply at a global scale. Aqueduct flow is numerically simulated by means of both steady (monthly) and unsteady (daily) analysis using the river modelling software HEC-RAS. The system capacity and hydraulic performance are studied for the fourth and fifth century aqueducts operating either as parallel lines or joining into a single system. An estimation of water delivered to Constantinople is proposed for typical dry, average and wet years. Results of this work are employed in a parallel research investigation on the management and distribution of water within the ancient city.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:756772 |
| Date | January 2018 |
| Creators | Ruggeri, Francesca |
| Contributors | Smith, Simon ; Crow, Jim |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/31521 |
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