Naslov
Spatial variations of the fresh-salt water interface of a Croatian coastal aquifer in the town of Biograd area

Autori
Kapelj, Janislav ; Kapelj, Sanja ; Biondić, Božidar

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Skup
24th Hydrology and Water Resources Simposium

Mjesto i datum
Auckland, Novi Zeland, 22.10.1997. - 27.10.1997

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
.

Sažetak
The Vransko Polje, near the town of Biograd, physiographically and geologically belongs to the karst region. It is composed of Cretaceous and Eocene carbonate rocks, marly deposits of Eocene flysch and Quaternary alluvial and diluvial deposits. From the tectonic point of view, this is flattened mildly folded area. The prevailing groundwater flow occurs parallelly to the structural directions, NW-SE. In some parts of this terrain, groundwater flows also perpendicularly to the structures. A part of water bearing deposits are under sea water influence. This paper deals with a detailed description of the results of hydrogeological study of the Vransko Polje area where, taking into account some recentmost explorations, certain earlier assumptions about the sea water impact on coastal aquifers have been changed. A dominant earlier opinion was that relatively thick Quaternary deposits, about 30 m thick, are sufficiently impermeable and able to prevent a sea water impact on the aquifers occurring far from the coast. Several extremely dry years and an increased use of groundwater in this area caused increases in water salinity of shallow pumping sites. Special hydrogeological explorations were launched. They consisted of water temperature and salinity measurements in boreholes and hydrochemical measurements of spring water and of the Vrana Lake water. Many observations have approved that the idea of an impermeability has no reason and that the fresh-saline water relationship includes a large zone of fresh/saline water mixture, i.e. of a coastal brackish water. The fresh water stratum is only 20 m thick in some places. The zone of mixture position depends on the geometry of impermeable barriers and the impact of this zone on hydrological conditions. The groundwater monitoring data served to delineate promising parts of the area in study for the groundwater abstraction for drinking and irrigation water supply.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA