The impact of sediment on open channel flow measurement in selected UK experimental basins

Most methods of open-channel flow gauging adopted in the UK for both water resources assessment and environmental research are subject to error due to the presence in streamflow of entrained suspended sediment and bedload. With techniques such as the Doppler velocity method and some acoustic methods, the presence of entrained sediment is an advantage, sometimes even central to the philosophy of the technique. However, for methods using fixed installations (structures) it can cause severe operational problems. Structures can suffer damage from sediment and often cannot be operated successfully to design or to use their laboratory-derived calibrations because of changes to fluid properties and sediment deposition within structures. The sediment problem is discussed, and some of the solutions described, in relation to a number of case studies involving gauging stations set up in UK research catchments. (C) 2003 Elsevier Ltd. All rights reserved.