Numerical modelling for environmental studies

With the increasing urbanization of modern societies, the need to optimize the use of space and resources has very quickly been combined with a social demand to take better account of the environmental consequences of new developments. The growing complexity of projects, with their multiplicity of themes, represents a major challenge for engineers and scientists today. Logically, methods capable of understanding the full complexity of a project are increasingly based on the concepts and tools of mathematical modelling. At the same time, assessment procedures have become increasingly structured to provide effective support for engineers and decision-makers, while also enabling communication with users and the public.

Since the 1990s, the principle of environmental assessment has developed as a new decision-making tool, particularly in North America and various European countries. Used in particular in land-use planning, this assessment process makes it possible to detect, at an early stage, the global effects of a project and the potential conflicts it may induce. The process gives rise to reports whose conclusions are used in decision-making by the public authorities concerned.

This approach is recognized as an effective, flexible and scalable means of integrating environmental concerns and sustainable development at the highest level of decision-making bodies, and informing them of the likely consequences of proposed actions. The main advantages of strategic environmental assessment are :

• examine the justification, necessity, feasibility and alternatives of a public policy, plan or program, and verify their environmental compatibility in order to direct the choice towards alternatives that are more favorable to the environment;

• take account of environmental problems at source, rather than just dealing with their symptoms and impacts, as in the case of environmental impact studies, which are devoted to smaller areas;

• create an appropriate context for environmental impact assessment, by collecting a good deal of environmental data at a higher planning level;

• highlight any cumulative effects at regional level.

Numerical modelling is expanding rapidly as computing resources increase, numerical methods improve and measurements are acquired. in situ with new generations of sensors. The maturity of thematic models and their association in a complex system now enable us to take a holistic approach to the natural environment, better able to provide the information required for decision-making.

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