A flood of new data on rainfall patterns

DUBLINERS can now expect better warnings of when they should batten down the hatches in anticipation of weather extremes, such as the flash floods and torrents which accompanied Hurricane Charlie when it struck the east coast.

As part of World Meteorological Day, celebrated last Sunday, Met Eireann with Dublin Corporation has begun Telflood, a two-year scheme which will explain more clearly how heavy rain can rapidly drain from mountain catchments, flow into plains and swamp large urban areas. The tail of a hurricane can easily trigger such events.

Other cities, such as Cork and Galway, which have been vulnerable to recent flooding will also benefit when the scheme is extended to these centres.

Telflood increases rain monitoring and, with the back-up of an advanced computer, can give a detailed profile of rain patterns, enabling more accurate forecasting and a better use of emergency services.

Urban design, in particular buildings and extensive paving, has had a dramatic affect on water flow. When this is combined with old, inadequate drains, rapid urban growth and higher population densities, there is a greater vulnerability to extreme weather.

Water is currently responsible for 70 per cent of natural disasters. There is evidence, albeit not conclusive, that Ireland will be subjected to more frequent storms, according to a Met Eireann meteorologist, Mr Tom Sheridan.

The main focus of Telflood will be the Dodder which in 1986 changed from an innocuous waterway into a raging river within hours.

Met Eireann, along with UCD's Centre for Water Resources Research, the Swedish Meteorological and Hydrological Institute and the University of Bologna, Italy, are involved in the EU sponsored project.

The corporation has agreed to join Met Eireann in expanding and upgrading rainfall monitoring stations. More automatic recorders will not only provide a continuous record of rainfall but will be connected to a central computer.

This will make data instantly available to both meteorologists and the corporation engineers responsible for water supply and protection against flooding. Data output from Met Eireann's short-range weather prediction model, HIRLAM, will help generate new water trend models.

While many see Ireland as a country which gets plenty of rain, Dublin in particular can suffer from shortages, witness supply restrictions in parts of the city earlier this year. Telflood will be equally beneficial during droughts, improving water management.

Met Eireann has also acquired a new computer which is expected to be some 15 times more powerful at forecasting than its predecessor.