Water Quality of the Vadose and Saturated Zone in Part of the Sedimentary Aquifer System of Kopais Basincentral Greece

Research Article

Austin J Hydrol. 2015;2(1): 1013.

Water Quality of the Vadose and Saturated Zone in Part of the Sedimentary Aquifer System of Kopais Basincentral Greece

Konstantinou V¹*, Arampatzis G², Panagopoulos A¹, Tziritis E¹ and Voudouris K²

¹Soil and Water Resources Institute, Hellenic Agricultural Organization, Greece

²Department of Geology, Aristotle University, Greece

*Corresponding author: Konstantinou V, Soil and Water Resources Institute, Hellenic Agricultural Organization, 57400 Sindos, Greece

Received: April 27, 2015; Accepted: May 29, 2015; Published: June 01, 2015


This paper aims at presenting the study of groundwater quality and more specifically of the aquifer and the leachates of sub-soil at the central part of Viotikos Kifisos river basin-central Greece. Quality characterization of the aquifer system was based on the principles set in the Water Framework Directive-WFD (2000/60/EC), adopting as standards the maximum admissible concentrations for water intended for human consumption. Results were based on the analysis of hydrochemical determinations carried out in 194 water samples collected from the vadose zone (through a prototype sampling system) and the shallow wells of the saturated zone, over the period 2009-2011. Spatio-temporal study of water quality characteristics was performed and the hydrochemical character of water samples was assessed using the expanded Durov diagram. As suggested by the analysis of the hydrochemical data, the bedrock of the basin that is formed of carbonate rocks and a schist-chert formation with ultrabasic blocks (mélange), control the dominant hydrochemical character of the analyzed water samples. Hence a strong calcium bicarbonate character prevails, whilst the existence of iron, manganese and nickel is characteristic and attributed to weathering of the lateritic horizons and supplementary to the weathering of ultrabasic blocks. Intensive agriculture that is the dominant activity in the wider region is clearly depicted especially in the vadose zone leachates, in the form of elevated ammonium concentrations that often exceed the maximum admissible concentration for water intended for potable use. In addition, nitrate concentrations in the saturated zone of the sedimentary aquifer system exceed the respective threshold in several cases.

Keywords: Groundwater; Hydrogeochemistry; Vadose zone; Water quality; Kopais basin


The leachates of the vadose (unsaturated) zone provide a representative sample, in order to assess the potential impact of anthropogenic activities to the environment and especially to the groundwater aquifer systems. Leachates are formed when water having uptake solutes infiltrates from the soil surface through the vadose zone, thus potentially reaching the saturated zone of an aquifer system. The vadose zone is not a water body in strict hydrogeological terms, however, the quality characteristics of the leachates, when moving through the vadose zone deeper than the bulk of the rooting system, provide important information about the potential pollution load, which could reach groundwater resources.

The study area (Figure 1) is located in the Prefecture of Viotia, in Central Greece and occupies the central part of the Viotikos Kifisos river basin. Intensive agricultural activities combined with the geological background, set the area notably vulnerable to pollution from agrochemicals, as can be revealed from both current measurements and analyses within previous research projects and development studies [1]. Moreover, the study area is of significant importance since the runoff of the basin end up through Kifisos River into Yliki Lake. The karstic aquifer system of the basin covers the potable water demands of the wider area, supports the locally developing terrestrial ecosystems and hosts strategic reservoirs of the Attica basin [2].