A sophisticated computer model developed by a Galway based company is at the forefront of defensive measures against potential environmental damage from oil spills in the Shannon Estuary.
The SEOS (Shannon Estuary Oil Spill) model was developed by MCS International. If an oil spill does occur, the operator only has to input details such as the date, time, temperature wind direction and type of the oil. The model calls on a database of details on around 100 types of oil and predicts how the oil in question will spread over the next several hours.
An important feature is the ability to predict the effects of placing booms to contain the slick. In a demonstration Dympna Kennan, an engineer with MCS International, showed how an oil spill in the estuary first looked as if it was going to beach on the Clare side, but then headed towards the southern bank.
"Without the model, valuable hours would have been lost deploying people and equipment at the wrong place," she said. She then showed the effects of placing booms in different locations five hours after the spill.
SEOS includes a "quasi3D" feature, showing the depth of the oil in the water by using different colours for various thicknesses. This helps an emergency team to corral off the thickest part of the spill.
SEOS is accessed via a computer in the Limerick Harbour Commission's HQ, linked by modem to a Dec Alpha computer in MCS's office in Galway which actually runs it. The model can be accessed from anywhere on the estuary by modem.
"We found it very easy to learn how to run it, because we are all familiar with computers and it's very user friendly," Captain Hugh Conlon said.
Behind the user friendly graphical interface and menus lurks some very sophisticated mathematics. "SEOS is a Lagrangian model, specifically developed to simulate the movement of oil, which uses particle tracking and random walk techniques to simulate; the movement of particles through the water column," Dympna Kennan said. "This method is more state of the art than the Eularian approach of earlier models."
SEOS was developed for the Shannon Estuary Anti Pollution Team, a consortium of Limerick and Foynes Harbour Commissioners, local authorities, oil companies and oil users such as the ESB and Aughinish Alumina.
While specific to oil pollution, SEOS builds on an earlier, simpler water quality model for the estuary, called SEWAM. The two dimensional Eularian model was developed by MCS in 1992 for Shannon Development and local authorities. "We use SEWAM to see what would be the effects on water quality of a new industry in one of our estates, for example," Ken Power, Shannon Development's Environmental Services Manager, said. "SEWAM built on a 1977 water quality model developed by the Environmental Research Unit, which is now part of the Environmental Protection Agency."
If EU funds become available, a geographic information system (GIS) will build further on SEOS/SEWAM, bringing into play the land adjoining the estuary. Like these other models, it would focus on water quality rather than air emissions, which are the source of ongoing controversy in the area.