The Project

In response to the UK Network on Conveyance in River Flood Plain Systems, a team of experts, led by staff at HR Wallingford have developed a new Conveyance Estimation System. This project was carried out under the Research Framework Agreement between HR Wallingford and the Environment Agency and the main output was the Conveyance Estimation System - a software tool to be adopted nationally. The work was funded by the Defra / EA Joint R&D Programme with supporting funding and resources from Scottish Executive, Northern Ireland Rivers Agency and the Natural Environment Research Council.

Background

From 1980 to 2000, a highly productive programme of research on the EPSRC Flood Channel Facility at HR Wallingford, on university laboratory flumes and natural channels was carried out by UK academics under largely EPSRC funding. This resulted in an advance in the understanding of flow phenomena in complex river and floodplain systems and constituted the leading international research over these two decades. This research improved the understanding of many of the processes which determine the flood capacity of river and flood plain systems. However, there was a concern that this new knowledge was not well transferred into practice within the UK flood management community, particularly with the design methodology being provided in a manual (Wark, James and Ackers, 1994) as distinct from being embedded within software.

In 2001, HR Wallingford carried out a Scoping Study in conjunction with the EPSRC Network on Conveyance in River Flood Plain Systems to examine the case for improved flood conveyance estimation and to define a work plan for the development of a new Conveyance Estimation System. Work involved wide consultation and included contributions by experts from the Universities of Birmingham and Glasgow, Centre of Ecology and Hydrology (CEH - Dorset) and Heriot-Watt University.

The scoping study identified a 2-year "Targeted Programme" of research to develop the Conveyance Estimation System (CES). This drew together and synthesised current knowledge and understanding to facilitate the estimation of conveyance by the various types of flood and drainage management users in the UK. A "Strategic Programme" of Research, with a longer timeframe has run in parallel with the Targeted Programme. Some of this has been carried out under the Flood Risk Management Research Consortium, while other related issues have been investigated out under responsive mode funding by EPSRC and by the science community internationally. This ongoing scientific research is monitored though the CES support contract, which aims to identify relevant new knowledge and capability to be incorporated into the CES in due course.

The development was carried out in close contact with a User Consultative Group representing the main user sectors. This group established the requirement for additional work to be done to produce a simple "CES Standalone" for use outside (as distinct from within) proprietary software.

Project tasks

The project was carried out as a number of tasks leading to the production of the Conveyance Estimation System (CES):

• Development of a 'Conveyance Generator' that estimates the channel conveyance capacity based on the channel geometry and roughness, which is suitable for in-bank and out-of-bank flow in all UK rivers and drains;
• Assembly of topographic and hydrometric data sets for testing of the Conveyance Generator;
• Gathering, validation and cataloguing of knowledge on the flow resistance of UK rivers;
• Development of a 'Roughness Advisor' - a dual paper/software system using photographs of different types of vegetation to 'match' a roughness coefficient to the channel under investigation, and linked to the River Habitat Survey;
• Implementation of the CES in the river modelling package ISIS;
• Pilot testing of the new CES (following initial training on the use of the CES);
• Production of a "CES Standalone" package in .exe form.

Outputs

• The Conveyance Estimation System (CES) which incorporates the Conveyance Generator and the Roughness Advisor. These have been provided as a stand alone software "package" designed to solve simpler types of assessment (e.g. for maintenance operations) and also to support parameter selection in hydraulic models, namely ISIS;
• The algorithms of the Conveyance Estimator are provided as open source to enable future research work and implementation in river model software; packages other than ISIS. The CES has since been incorporated in InfoWorks RS;
• User documentation and conveyance and roughness manuals;
• Supporting technical reports produced during the course of the project.