Logic-Based Decision Support for Strategic Environmental *Assessment* 3 LPAD. Section 6 presents experimental results on a real energy plan. A discussion and a description of open issues conclude the paper.

## 2 Strategic Environmental Assessment

Regional planning is the science of efficient placement of land use activities and infrastructures for the sustainable growth of a region. Our case **study is the Emilia** Romagna region of Italy, and we developed this work on real data provided by the environmental regional agency. Regional plans are classified into *types***; the SEA**
is legally required for eleven types of plans (namely Agriculture, Forest, Fishing, Energy, Industry, Transport, Waste, Water, Telecommunication, Tourism, Urban and Environmental plans), those addressed in this work. Each plan **defines activities** that should be carried out during the plan's implementation. Activities **are roughly** divided into six types:
- **infrastructures and plants;** - **buildings and land use transformations;** - **resource extraction;** - **modifications of hydraulic regime;**
- **industrial transformations;**
- **environmental management.**
Before any implementation, these plans have to be environmentally assessed, under the *Strategic Environmental Assessment Directive***. SEA is a method for incorporating environmental considerations into policies, plans and programs that is**
prescribed by European Union policy.

One of the instruments used for assessing a regional plan in Emilia Romagna are the so-called *coaxial matrices***, that are a development of the network method**
(Sorensen and Moss 1973).

One matrix M **defines the dependencies between the above-mentioned activities**
contained in a plan and positive and negative *impacts* **(also called** *pressures***) on the**
environment. Each element mij of the matrix M **defines a qualitative dependency**
between the activity i and the negative or positive impact j**. The dependency can be**
high, medium, low or *null***. Examples of negative impacts are energy, water and land**
consumption, variation of water flows, water and air pollution and so **on. Examples** of positive impacts are reduction of water/air pollution, reduction of greenhouse gas emission, reduction of noise, natural resource saving, creation of new ecosystems and so on.

The second matrix N **defines how the impacts influence environmental receptors. Each element** n i j of the matrix N **defines a qualitative dependency between**
the negative or positive impact i and an environmental receptor j**. Again the dependency can be** high, medium, low or *null***. Examples of environmental receptors**
are the quality of surface water and groundwater, quality of landscapes, energy availability, wildlife wellness and so on.

The matrices currently used in Emilia Romagna contain 93 activities, 29 **negative**
impacts, 19 positive impacts and 23 receptors and refer to the above-mentioned 11 plans.