Current conditions of saltwater intrusion in the coastal Rhodope aquifer system, northeastern Greece

Abstract The geological, hydrogeological and hydrochemical regimes of the coastal Rhodope aquifer system, northeastern Greece, are described. The aquifer system includes two aquifers within coarse grained alluvial sediments. Both vertical and lateral saline water intrusion occurs, usually caused by over pumping. Water has been pumped from the aquifer system at an ever-increasing rate for many years. Water samples for chemical analyses were obtained from 36 productive wells and from 5 research wells at several depths to cover the entire study area. The EC and chloride concentration distribution clearly illustrate the large extent of saline water intrusion in the aquifer system of the study area. Although the ionic content of groundwater of the study area is highly variable, the dominant anions are HCO3− and Cl− and the dominant cations are Na+ and Ca2+. Water in the saline parts of the confined aquifer is generally of the Ca2+-Cl− type. Evidence of cation exchange and reverse cation reaction between fresh and saltwater in the Rhodope aquifer system are reflected in the Piper diagram and the expanded Durov hydrochemical diagram, respectively, both for productive and research wells. The results of this study show that the development of a strategy for managing the aquifer system is vitally necessary.

[1]  I. Koukouvelas,et al.  Tectonic stages along a traverse cross cutting the Rhodopian zone (Greece) , 1990 .

[2]  A. Cheng,et al.  Seawater intrusion in coastal aquifers : concepts, methods, and practices , 1999 .

[3]  S. Bottrell,et al.  Processes affecting groundwater chemistry in a zone of saline intrusion into an urban sandstone aquifer , 1998 .

[4]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[5]  J. Lloyd,et al.  Natural Inorganic Hydrochemistry in Relation to Groundwater: An Introduction , 1985 .

[6]  J. Lloyd.  The hydrochemistry of the aquifers of North-Eastern Jordan , 1965 .

[7]  J. G. Conijn,et al.  Evaluating farm performance using agri-environmental indicators: recent experiences for nitrogen management in The Netherlands. , 2007, Journal of environmental management.

[8]  C. Petalas,et al.  Simulation of intense salinization phenomena in coastal aquifers—the case of the coastal aquifers of Thrace , 2006 .

[9]  C. Appelo,et al.  Geochemistry, groundwater and pollution , 1993 .

[10]  Gideon Oron,et al.  Desalination technology for optimal renovation of saline groundwater in a natural reservoir , 2000 .

[11]  E. Giménez,et al.  Hydrogeochemical analysis of salinization processes in the coastal aquifer of Oropesa (Castellón, Spain) , 1997 .

[12]  P. Domenico,et al.  Physical and chemical hydrogeology , 1990 .

[13]  Á. Vallejos,et al.  Hydrogeochemical Characteristics of Processes in the Temara Aquifer in Northwestern Morocco , 1999 .

[14]  J. Herman,et al.  Regional Hydrogeochemistry of a Modern Coastal Mixing Zone , 1996 .

[15]  C. Petalas,et al.  Origin and distribution of saline groundwaters in the upper Miocene aquifer system, coastal Rhodope area, northeastern Greece , 1999 .

[16]  A. Keeler,et al.  The adoption of best management practices to reduce agricultural water contamination , 1999 .

[17]  Arthur M. Piper,et al.  A graphic procedure in the geochemical interpretation of water-analyses , 1944 .