One of the most important problems that the surface wetlands of the Mediterranean sea face, is the accumulation of nutritional elements (ions of nitrogen and phosphorus), resulting in eutrophication, a phenomenon that reduces both the water quality and the biodiversity of the ecosystem. The described accumulation is the result of two main causes. Firstly, the fact that in the Mediterranean basin, one of the main occupations of the inhabitants is agriculture. Agriculture and more specifically, intensive agriculture, demands the use of important quantities of fertilizers, rich in nutritional elements. This results in the accumulation of important quantities of nutritional elements in the river beds.

However, besides agriculture and urban and domestic sludge, large quantities of nutritional substances are accumulated in the environment. More specifically in Crete the problem is more intense because of:

  1. There is no extended biological cleaning net, resulting in the crude entrance of urban and domestic sludge in the river beds.
  2. The processing of sludge in the existing biological cleaning stations, is often inadequate, and as a result the aggravation in the rivers continues, in a smaller scale however.


Because of the limited quantities of surface water in the Mediterranean area and with the used quantities growing constantly, the problems worsen, and so it is necessary to maintain these ecosystems in a good physicochemical and ecological level.

The above situation, directs the immediate and right confrontation of the problems that have already accumulated.

The European Union, after evaluating the importance of the little and limited Mediterranean wetlands and believing that no actual measures have been taken up until today for their protection, has prioritized through its policy the wetlands preservation and rational use.

In Crete, where the rivers are of a small length and have a limited or ephemerous water flow, they are highly important however in the preservation of the hydrological situation of the area,

the measures that have been taken are inadequate and the administration policy, concerning those rivers, is deficient.

At the same time however, there are some suitable administration tools, like for example the ones from some Εnvironmental Decision Support Systems –EDSS, which are basically computational models of estimation, that actually help the work of the water administrating authorities

They also help them to make the right decisions. EDSSs like these, exist in many years, in other European countries. For example MLONERIS, that was designed for the administration of the rivers in Germany.

Our information about the after-effects of nutritional substances in the functionality of the Mediterranean rivers has been inadequate, up until recently. The European Program STREAMES aims to cover the above gap. The STREAMES program is in its completion phase.

At the same time, the above program, is characterized by an innovation in its structure.

Besides the research team, that studies the consequences of the nutritional substances, a second team is also part of the project. This team is consisted of specialists in the development of Environmental Systems of Supporting Decisions, and is directly provided with the results of the first team, so that by the end of the project, an ESSD can be created. This ESSD will be called Expert System – ES.

This system, which is a basic product of the above project, aims to provide an aid for the supervising commissions of water administration, so that, they will be able to use the minimum possible information to:

  • Evaluate the state of a river
  • Sort the problems,
  • Discover their causes
  • Select one of the suggested appropriate solutions


Another innovation for the European reality, of the STREAMES project, is the presence of a third team that is exclusively consisted of water administration commissions from the countries that participate in the program. The role of this team, is to share their experience in the creation of ES and closely watch over its development, since they will be the ultimate users of it. It is predicted that ES will be very efficient for the Mediterranean area, however it is possible to show some weaknesses in its application. The main reason for that is the fact that the Mediterranean area, despite having the same climate type, it shows some topical differentiations. For example, in the Eastern Mediterranean, there are frequent periods of drought, which seriously affect the structure and the functionality of the river ecosystems and contribute to the creation of torrents. This practically means that some parameters, like the water flow, keep changing during the year. Based on this fact, we believe that a final product as important as the ES, could become even more useful, if its function focuses on the natural environment of the Southeastern Mediterranean, and more specifically Crete.


The main target of the Expert System-Crete (ES-Cr) subproject, that we suggest, is to evaluate initially, the suitability of application for the ES, in the ecosystems of the Cretan rivers, and then with the appropriate settings and improvements, to perfectly adjust it to the conditions of the wider area. This way, the better functionality and efficiency of ES will be ensured, since it’s so important to administrate the surface water in an appropriate way in the time being.


This adapted ES-Cr could be used not only by the administrative commissions of water in Crete, but by the administrative commissions of Southern Aegean as well, because of the similarities in the weather conditions and the landscape.


The suggested subproject, is basically (a) the application and (b) the continuation of the European project: “Human effects on nutrient cycling in fluvial ecosystems: The development of an Expert System to assess stream water quality management at reach scale” (STREAMES -EVK1-2000-22083), with a duration of three years (3/2001- 2/2004).


STREAMES is a Mediterranean program, since six Mediterranean countries are co working on it. Greece, Spain, Italy, Portugal, France and Israel, and Germany and Austria that take part as report countries. As far as our country is concerned, the commissions and researchers that participate are all coming from Crete. More specifically Dr. Αικ. Βορεάδου (Natural History Museum of the University of Crete), Dr. Γ. Μαρκάκης (Τ.Ε.Ι. Κρήτης) και Dr. Θ. Μαγκανάς (Οργανισμός Ανάπτυξης Ανατολικής Κρήτης -ΟΑΝΑΚ), as the last commission user.

The main targets of the program are:

To record and evaluate the marking and the non marking sources of notional substances in the rivers of Crete.

To find the mechanisms that controls the absorbedness of nutritional substances in the ecosystems of the studied rivers.

To develop an Environmental System for Supporting Decisions (ESSD) , that will be used as a model for the administration of these degraded ecosystems.


The final product of the above project, will be an Environmental System for Supporting Decisions, named ExpertSystem (ES). It will be using a small set of initial data (geomorphologic data, biotic parameters, chemical parameters etc) which will be provided by the researchers or the administrative authority and will have the following goals:

To be able to diagnose the condition of the river by giving a sequence of the problems that it detected.

After that, to be able to suggest solutions to the administrative authorities.

And finally to be able through the process of “simulation”, to analyze several possible scenarios for solving the problems, giving at the same time and an estimation regarding their solution (prognosis).



ES will be working, with the use of a knowledge base, which will be the result of empirical or systematical knowledge (for example sampling in the rivers with a questionnaire given to the administrators, references etc). After that, with the use of Decision Trees ES ES will be giving the results. A mapping of the rivers with GIS, is necessary for the initial calculation of the spots of the incoming nutritional substances (with the use of the MONERIS program, developed in countries of central Europe)


The role of this specific European program, is very important since it involves all the Mediterranean rivers, in which the use of an ES, is applied for the first time. The

participation of the researchers of the main team in the suggested subproject in the European project STREAMES, is the following:

Δρ. Αικ. Βορεάδου participates in the work packets concerning the influence of nutritional substances in the structure and functionability of the river ecosystems.

Δρ. Γ. Μαρκάκης in the work packet concerning the development of ES (WP4).

Δρ. Θ. Μαγκανάς from the commission user (ΟΑΝΑΚ), participates in the work packet concerning the observation of the development, the use and the spread of ES (WP5)

The program started in May of 2001, and ES is almost complete, as of today. (There’s already a DEMO version, written in Java) and in September of 2003, a user friendly version will be presented in a gala that will take place in the Museum of Natural History of the University of Crete, in Heraklion. Announcements have already been done, from the research teams in several conferences, two out of which(with the participation of Greek researchers), are given in other units (A5) and the research team is already moving to the composition of articles for magazines of international status.