Publication Date:
2017-04-04
Description:
In the study area physical and chemical
factors control the composition of surface and
groundwaters, which in turn determine the water
quality of the “Biviere di Gela” lake. These factors
combine to create diverse water types which change
their compositional character spatially as rainfall
infiltrates the soil zone, moves down a topographically
defined flow path, and interacts with bedrock
minerals. Low-salinity waters, which represent the
initial stage of underground circulation, start dissolving
calcium carbonate from the local rocks. The
progressive increase in salinity, characterized by
substantially higher Ca, SO4, Na and Cl concentrations,
suggests that dissolution of CaSO4 and NaCl is
an important process during water–rock interactions.
The “Biviere di Gela” lake is often separated into two
units (Lago Grande and Lago Piccolo). “Lago
Grande” water is generally of Na-SO4-Cl-type,
whereas “Lago Piccolo” water is of Na-Cl-SO4-type.
Their total content of dissolved salts varies with
season, the amount of rainfall, and inflow of ground
and drainage water. Over time, an increasing trend
towards greater salinity and also sudden changes in
the relative abundances of Cl and SO4 have been
recorded for the “Lago Grande.” The isotope composition
of the lake water appears to be affected by
inflow of ground and surface waters and also by
evaporative loss. The nitrate content of waters from
the recharge basin is of particular concern because it
contributes to lake eutrophication. The trace element
contents do not evidence the presence of any
significant metal contamination of lake waters, although
a future potential hazard of metals bioaccumulation
by the aquatic biota must be taken into
consideration. Finally, a water balance for the basin
shows that a drop in precipitation of about 20% might
be critical for lake survival.
Description:
Published
Description:
JCR Journal
Description:
reserved
Keywords:
wetland area
;
hydrogeochemistry
;
environmental geochemistry
;
isotope geochemistry
;
water balance
;
03. Hydrosphere::03.02. Hydrology::03.02.02. Hydrological processes: interaction, transport, dynamics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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