Bolton Experiment

The Bolton Experiment: An Experimental Test of the Use of Microwave Attenuation to improve Rainfall Estimates in Urban Areas, and hence to Enhance Flood Warning

The Bolton Experiment was a NERC project with matching funds from industry which took place between 1999 and 2002.It was a collaboration between the University of Essex (Propagation and Remote Sensing group, the University of Salford (Telford Research Institute), and the Rutherford Appleton Laboratory (Radiocommunications Research Unit) and the industrial partners North West Water Plc and Norweb Communications (both companies of United Utilities), the UK Meteorological Office, The Environment Agency and Crown Castle International.

The purpose of the study is to test the proposal developed at Essex, in conjunction with RAL, that the difference in attenuation at two microwave frequencies along a given path provides an accurate estimate of path-integrated rainfall rate, and to investigate its application to hydrological studies of urban catchments.

The catchment selected for study is the Bolton catchment, in which the town is largely surrounded by hills, and the River Croal is carried in culverts in the town centre. Four microwave links will be set up, three of them dual frequency and one single frequency. In addition to data from microwave links and radar, there will also be data available from a number of telemetered tipping bucket raingauges.

Details of the findings of the experiment can be found in these published papers. The experiment led directly to a follow-up project that extends the methods to sites in Germany and Italy (as well as Bolton). More on this project, entitled MANTISSA (Microwave Attenuation as a New Tool for Improving Stormwater Supervision Administration), can be found via the MANTISSA website.

This dataset is public and can be accessed from the BADC archives from http://badc.nerc.ac.uk/browse/badc/bolton

If you use the data please acknowledge the data providers.

The data from the Bolton experiment are now available for research purposes. If you use the data please acknowledge the data providers.

Data was collected from microwave and radar links and a number of telemetered tipping bucket raingauges. The adjacent relief map of the catchment area, shows the position of the links (white lines) together with the locations of the rainguages (blue dots). View larger image

Four links were set up, three dual-frequency and one single-frequency. The shorter links to the west cover Bolton's town centre. The link to the east is a link to the UK Met Office Hameldon Hill C-band weather radar. Not only does this pass along the valley of the River Irwell, but, being radial from the radar, enables estimates of the effects of attenuation on radar data to be estimated. Data were also available from a number of telemetered tipping bucket raingauges most of which belong to North West Water and the Environment Agency. The Met Office also installed two automatic weather stations (marked by red crosses).

The division of work was as follows:

• The University of Essex created a central archive of data (microwave, raingauge and radar). It also carried out data analysis to extract information from the link attenuation data on path-averaged rainfall rate, and compared the results with those obtained from the raingauges and the radar.
• RAL was responsible for assembling and installing the microwave receivers and transmitters. The antenna installations and sites were the responsibilities of Norweb Communications and Crown Castle International.
• The University of Salford performed all the hydrological modelling, in conjunction with models provided by North West Water plc.