ERCIM News No.34 - July 1998

Environmental Modelling at IACM-FORTH: Aiming at the Future

by Nikolaos Kampanis

Scientific computing at the Institute of Applied and Computational Mathematics (IACM) of FORTH has focused on the development of mathematical and numerical techniques for solving partial differential equations which describe various physical phenomena and technological processes, and on their computer implementation in user-friendly integrated systems supporting the pre- and post-processing of scientific computations, Graphical Information System applications, parallelization, visualization and decision making techniques.

Over the years a large amount of expertise has been developed on mathematical and computational methods for wave propagation problems, especially in the area of direct and inverse problems of underwater acoustics. For the direct problem several computational models for predicting the acoustic field in the sea have been developed and validated. The models are based on finite element and finite difference discretizations of the Helmholtz equation and its paraxial approximations and use state-of-the-art mesh generation and numerical linear algebra techniques. For the inverse problem several techniques have been proposed and tested for the purposes of identifying oceanographic and geoacoustic parameters. These techniques couple on site measurements and computational prediction models.

IACM is now in the process of expanding its involvement in environmental modelling. IACM is located in Heraklion, on the island of Crete in the southern part of Greece, an area whose economy is mainly based on local small-to-medium size industry, agriculture and tourism. The challenge of preserving environmental quality in the course of future development is of paramount importance. We intend to relate more of our research to the study of regional environmental problems and try to support the decision making processes and the regional planning of the local authorities, with which we have long established close cooperation.

There are several components of potential environmental modelling activities in Crete. One is the problem of the dispersion of water transported pollutants. For example, the disposal of fluid waste from local olive oil processing plants (Crete has a big olive production and provides significant quantities of processed olive oil to the domestic and international market) has to be treated efficiently, since it may be carried away by rain or rivers. Eutrophication phenomena due to the contamination of water basins by chemical fertilizers, and pollution of the sea, eg at the south of Crete where extensive areas are occupied by greenhouses, may destroy usable water supplies and the coastal zone. Other kinds of solid and fluid waste, due to the increase of the near-shore population and extensive tourist development very close to the coastline over decades of kilometres, are disposed in the sea. Hence, regional planning decisions need to be supported eg on the optimal location of industrial, touristic and other environment-affecting installations, especially when these are close to the coast. Therefore the study of coastal circulation, including local currents and surface motion, is important.

IACM currently participates in two projects related to water resources management. Both are in collaboration with INRIA, Rocquencourt, and scientists and institutions from several countries of North Africa and the Middle East. The first, funded by the Greek-French integrated action PLATON' 98 program, is the numerical simulation and prevention of water reservoir eutrophication. The other, funded by the European Union DGIII ESPRIT/INCO-DC program, has as its general theme flood modelling with use of HPCN and GIS, and aims towards providing tools to support design of policies for a rational use of water supplies.

Due to its geographic position and regional climate conditions, Crete has long periods of strong north and south winds, which in some places are reinforced by complex mountain terrain. Hence, of major importance is the exploitation of wind and water wave energy resources, and Crete has been characterized by the Greek government as a privileged region for development and use of renewable energy sources. Not less important is the exploitation of solar energy due to the very long cloudless periods. Installation of wind farms is advancing at several places in Crete and the collection of field measurements and short-term weather forecasting will be of major importance for their optimal operational deployment. Agriculture will also benefit from such activities, that will also aid in the controlled and localized use of pesticides.

All this leads us to the conclusion that the monitoring of the atmospheric boundary layer inland and at coastal zones, as well as the simulation and forecasting of athmospheric flows on a regional basis using computational models will be very important. IACM has taken several steps to establish collaboration with scientists in Europe and in the US for these purposes.

Please contact:

Nikolaos Kampanis - IACM-FORTH
Tel: +30 81 39 17 80
E-mail: kampanis@iacm.forth.gr

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