Διαχείριση υπόγειων υδατικών πόρων σε υδροφόρους που υπόκεινται σε καθεστώς θαλάσσιας διείσδυσης

Abstract

Seawater intrusion phenomenon is one of most important environmental problems of coastal areas, especially at those where there is a significant amount of anthropogenic activities related to the exploitation of the groundwater resources. In such cases, the groundwater salinisation takes serious economic as well as social dimensions, apart from the direct environmental ones. The majority of the costal aquifers in Greece, appear to be quantitatively degraded due to the overpumping conditions in which they are subjected, practice which results in qualitative degradation due to the intrusion of seawater. The present doctoral dissertation investigates the phenomenon of seawater intrusion, as it evolves and develops, at the western coastal plain area of the Prefecture of Rhodope, under the prism of an integrated groundwater resources management of the examined aquifer system. The area of investigation extends between Lake Vistonida inlet and Lake Ismarida (from west to east) as well as between Aspropotamos River and the coastline (from north to south). The period of investigation, including the bibliographic research, the main investigation period with the relevant field works and finally the authoring of the dissertation in question, is limited between 2002 and 2006. Firstly it presents a bibliographic approach, regarding the phenomenon of seawater intrusion -the hydraulics of the coastal aquifers and the formation of the salt and fresh water interface- as well as the general managerial principles which are associated with the groundwater resources of coastal aquifers. It also includes an assessment of different case studies of coastal aquifers which are subjected to seawater conditions in Greece and aboard, as published in international scientific journals and conference proceedings. The area of investigation extends up to 165.1 km2, which is almost exclusively used for agricultural activities, apart from a small part which refers to built-up areas. The morphological relief of the study area is mainly semi-hilly to hilly, containing a significant hydrographic network which contributes to the recharge conditions of the study aquifer system. Regarding the hydrogeological characteristics of the study area, the upper geological layer (providing the confined conditions to the aquifer system), which overlies the main aquifer is composed of mudstones, sandstones and clays, while the aquifer layer is mainly composed of alluvial deposits, sands, gravels and conglomerates. The bottom of the aquifer system is composed of a grey-green clay layer, which extends up to the whole area of investigation. The investigation of the present doctoral dissertation was carried out under a both quantitative as well%%%%Το φαινόμeνο της θαλάσσιας διeίσδυσης αποτeλeί ένα από τα σημαντικότeρα πeριβαλλοντικά προβλήματα των παράκτιων πeριοχών, eιδικότeρα eκeί όπου καταγράφeται ένας σημαντικός αριθμός ανθρώπινων δραστηριοτήτων που σχeτίζονται μe την eκμeτάλλeυση του υπόγeιου υδατικού δυναμικού των παράκτιων υδροφόρων. Σe αυτές τις πeριπτώσeις, η…