HYREX projects

1. Design of radar/raingauge networks for hydrological use

Principal Investigators: R.J. Moore, CEH Wallingford (formerly Institute of Hydrology), Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB.

Aims: The aim of the project is to review the requirements for rainfall field estimates in the hydrological sciences and to establish how these can be best met using networks of radars and raingauges.

Methodology and approach: A unique dataset collected from a dense network of raingauges and radars will be subject to statistical analysis and physical interpretation to better understand (i) the accuracy of different sensors to measure rainfall and (ii) the sensitivity of catchment flow models to rainfall uncertainty and variability.

Start and end date: 1/4/93 to 31/3/96

2. Spatial-Temporal Rainfall fields: Modelling and Statistical Aspects

Principal Investigators: Prof H.S. Wheater, Civil Engineering Dept., Imperial College, London SW7 2BU; Prof. V. Isham, Statistical Science Dept., University College, London WC1E 6BT and Prof Sir David Cox, F.R.S., Nuffield College, Oxford OX1 1NF.

Aims: Analysis and modelling of spatial rainfall to provide an improved statistical basis for hydrological applications; provision of general statistical advice to the HYREX programme.

Methodology and approach: Following preliminary analysis of HYREX and related data, further development and implementation of spatial-temporal rainfall models will be undertaken and evaluation of their hydrological applications.

Start and end date: 1/4/93 to 19/5/97

3. The development of a stochastic space-time rainfall forecasting system for real-time flow forecasting

Principal Investigators: Prof P.E. O'Connell and Dr A.V. Metcalfe, Department of Civil Engineering, Cassie Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU.

Aims: To develop the Modified Turning Bands (MTB) Model for space-time rainfall into a forecasting system, and to optimize the technique with respect to the accuracy of a catchment response forecast.

Methodology and approach: After conditionally fitting a synthetic rainstorm as produced by the MTB Model to current radar data, the model will be run forwards in time to simulate future events, and thereby produce a rainfall forecast in time and space. Catchment modelling systems (SHE and ARNO) will be used as test-beds for assessing the performance of the technique.

Start and end date: 1/4/93 to 31/3/96

4. Methods for short-period precipitation and flow forecasting incorporating radar data

Principal Investigators: Prof A.J. Thorpe and Dr M.A. Pedder, JCMM, University of Reading, 2 Earley Gate, Whiteknights, Reading, RG6 2AU; and Mr R.J. Moore, CEH Wallingford, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB.

Aims: To develop techniques for the assimilation of radar data into mesoscale and finer scale meteorological models and to investigate their conjunctive use with hydrological models for rainfall and flow forecasting.

Methodology and approach: The aims will be achieved through (i) the use of 4D data assimilation techniques, (ii) the development of a high resolution rainfall model incorporating simple process descriptions and data assimilation, and (iii) an assessment of the rainfall model predictions in hydrological catchment models, with reference to observed rainfall, soil moisture and flow data.

Start and end date: 1/11/93 to 31/10/96

5. Verification of polarisation radar techniques for improving estimates of rainfall

Principal Investigators: Dr A.J. Illingworth, University of Reading, 2 Earley Gate, Whiteknights, Reading, RG6 2AU. Mr J.W.F. Goddard, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX.

Aims: To quantify how polarisation radar parameters (especially differential phase shift) can improve rainfall estimates for hydrological purposes; to investigate these techniques for removing clutter and correcting for the bright band.

Methodology and approach: To gather polarisation radar data with the Chilbolton radar, to compare inferred rain rates with: (i) a line of rapid response gauges close to the radar, and (on the same azimuth); (ii) gauges over the Brue catchment; (iii) in-situ particle measurements on the C-130 aircraft.

Start and end date: 1/4/93 to 31/3/96

6. Radar Hydrometeorology, using a vertically pointing radar

Principal Investigators: Prof I.D. Cluckie and Dr K.A. Tilford, Department of Civil Engineering, University of Salford, Salford M5 4WT

Aims: To study the hydrometeorology of rainfall systems in orographic and non-orographic regions with a high resolution vertical pointing radar.

Methodology and approach: To deploy at least two high resolution vertically pointing X-band radars to obtain vertical reflectivity profiles of rainfall systems. A transect experiment will study orographic effects.

Start and end date: 1/3/93 to 29/2/96