Fotios Pliakas

Simulation of Seawater Intrusion in Coastal Aquifers: Forty Five-Years Exploitation in an Eastern Coast Aquifer in NE Tunisia

Management of groundwater resources involves the allocation of groundwater supplies and water quality to competing water demands and uses. The resource allocation problem is characterized by conflicting objectives and complex hydrologic and environmental constraints, especially in coastal aquifers. The development of mathematical simulation models provides groundwater planners with quantitative techniques for analyzing alternatives groundwater resources management. The gathered knowledge was then used to build and to calibrate a 3D transient model of 45 years time period (1963-2008). The numerical model was used further to discuss some issues on the management of the regional groundwater resources. The calibration of the 3D model has been achieved in a time dependent, iterative and semi- automatic fashion. This paper describes a 3-D seawater intrusion modeling process for a specified study area in Eastern Coast aquifer, in NE Tunisia. The simulation results presented in this paper are based on the density-dependent miscible flow and transport modeling approach for simulation of seawater intrusion in coastal aquifers. Response evaluations con- sider the effects of vertical recharge on seawater intrusion, effects of boundary conditions, and effects of spatially varying pumping from the aquifer.

SWOT analysis in groundwater resources management of coastal aquifers: a case study from Greece

This paper applies a SWOT (strengths, weaknesses, opportunities and threats) analysis to groundwater resources management of a coastal aquifer in northern Greece typical of those subjected to seawater intrusion. SWOT analysis is found to be a useful managerial tool, incorporating interdisciplinary issues – engineering, scientific, legislative, economic and social – which are difficult to quantify, in order to identify the main environmental problem of the study area, which is overexploitation of the groundwater resources (and seawater intrusion as a consequence). Based on the main outcomes of the SWOT model, specific countermeasures are suggested in order to combat the over-pumping of the aquifers resources which leads to overexploitation of the groundwater potential.

Application of SWOT analysis for the management of transboundary River Evros (Bulgaria, Greece, Turkey)

River Evros is a transboundary river flowing through Bulgaria, Greece and Turkey and coincides with the borderline among them for a considerable part of its length in the downstream part of its basin. River Evros is historically engaged to a long series of serious and devastating flood events with high socio-economical costs and environmental impacts on the riparian communities and even on the national economies of the three neighbouring countries which share the area of its hydrological basin. Besides, there have been a number of serious groundwater pollution incidents which have been identified at certain parts of the basin. Thus, the environmental problems encountered in the river’s basin, represent both quantitative and qualitative ones. This paper investigates the main reasons for the faced transboundary environmental, socio-economic and developmental problems engaged to the functioning of the River Evros natural system and its management, based on a SWOT analysis (acronym which stands for strengths, weaknesses, opportunities and threats). The ultimate goal of the investigation is to make sound conclusions, acting as a tool which may well facilitate a, badly needed, rational and integrated management of the entire transboundary surface and groundwater resources of the River Evros system (main river and its tributaries).

SPECIAL ISSUE PREFACE - “Groundwater Resources Management in Coastal Regions”

Management of groundwater resources is a key issue for countries which are located within sensitive hydrologic or hydrogeologic basins, playing a vital -or centralrole in sustainable development, as well as on the long-term geopolitical stability. Coastal countries and more specifically coastal aquifers are considered as such sensitive regions. The fact that groundwater is one of the most important freshwater resources on earth, with almost 90% of available freshwater quantities found in hydrogeologic systems, makes the management of groundwater resources an issue of paramount importance. With this special issue, we wish to initiate an open discussion or platform, which will contain different approaches for the managament of groundwaters in such hydrollogically sensitive regions. Sensitivity lies on both quantitative as well as qualitative characteristics of the region, including the majority of environmental water problems such as: groundwater contamination and pollution, aquifer overexploitation, seawater intrusion, groundwater-surface water interactions and management of water resources.