 |
| Titel |
Assessment of Groundwater Resources in the North-Central coast of Crete, Greece using Geochemical Methods and GIS as a tool |
| VerfasserIn |
Despina Kalisperi, Maria Kouli, Nikos Lydakis-Simantiris, Pantelis Soupios |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053873
|
|
|
|
|
|
| Zusammenfassung |
| In the Mediterranean and particularly in its islands the water is scarce, due to their
geographical isolation and climate change. One particular problem is seawater intrusion into
near-shore aquifers. A place where this issue is of great importance is the island of Crete,
Greece. The poorly-understood Geropotamos catchment, on the north-central coast of
Crete is invaded in some places by salt water from the Aegean Sea, with impact
on freshwater supplies for domestic and business uses, including agriculture and
tourism. The geological setting of the study area is considered complex, as Miocene
biogenic limestones, marls, clays and conglomerates crop out in the central and the
western part and clastic limestones and dolomites of the Tripolis and Plattenkalk
nappe (the bedrock) in the eastern part of the study area. The phyllite-quartzite
nappe (which forms the oldest rock of the study area) lays on the northern part of
Geropotamos basin. The local tectonic regime of the study area is characterized by faults of
NW-SE and NE-SW directions. Three (3) water samplings carried out. At each
sampling, samples from twenty-two (22) boreholes and two springs were analyzed and
sixteen (16) chemical parameters were determined, including physical and aggregate
properties, metals & inorganic nonmetallic constituents. Detailed geochemical analysis,
including Piper, Stiff, and Dispersion diagrams and factors controlling the groundwater
quality, was accomplished showing very good results. All data were inserted in GIS
environment and groundwater quality maps were produced (based on Civita et al., 1993 &
Ground Quality Index, Babiker 2007). The evidence presented is best interpreted that
the saline water is due to seawater intrusion. This disproves previous work, where
suggestions that Miocene evaporites led to groundwater salination. It is indicated that
saline intrusion is likely to occur along fractures in a fault zone through otherwise
low-permeability phyllite-quartzite bedrock, and it is emphasized the critical role
of fracture pathways in salination problems of coastal aquifers. So, these results
can lend a hand to find solutions for water management in order to achieve and
preserve a long-term protection of the available groundwater resources of the area. |
|
|
|
|
|
|