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| Titel |
Groundwater-surface water interactions in fractured Mediterranean mountain environments |
| VerfasserIn |
Marinos Eliades, Adriana Bruggeman, Manfred A. Lange |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250095103
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| Publikation (Nr.) |
 EGU/EGU2014-10545.pdf |
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| Zusammenfassung |
| Groundwater and surface-water systems interact in a variety of geological, morphological,
and climatic settings. Vegetation also plays a key role in these interactions as it transfers
water from the subsurface and groundwater table towards the surface, where it is redistributed
by plants and trees in different soil depths. Cyprus is at the drier end of the precipitation
spectrum of the Mediterranean region and has intense seasonal variations in precipitation
with frequent droughts. In order to confront water scarcity issues and improve water
management plans in the future, we need to obtain a better understanding of the
groundwater and surface-water interactions and quantify the hydrological processes
in this complex fractured Mediterranean mountain environment. The upstream
and midstream of Peristerona watershed was selected as the study area (77 km2).
It is a forested mountain watershed with steep slopes (mean 22o) and elevation
varying from 417 to 1543 m. The main formations in the area are lower and upper
pillow lavas, basalt, diabase and gabbro. From a hydrogeological point of view the
upstream area consists mainly of heavily fractured intrusive formations that can hold
groundwater inside the fractured zones and in some areas it consists of plutonic rocks
with springs. The midstream area is dominated by volcanics with submarine pillow
lavas.
To assess the surface and groundwater interactions a nested watershed approach will be
followed with the synthesis and collation of hydrometric data through a dense monitoring
network. Continuous measurements of rainfall, runoff and groundwater levels will
be taken. Watershed characteristics will be processed in GIS environment. Also
measurements of environmental stable isotopes (O18and H2) will be taken. In addition sap
flow instruments will be installed in Pinus brutia species among with soil moisture
sensors. Results will quantify the water uptake by trees (Pinus Brutia sp.) and the
hydraulic redistribution back to the different soil depths. It will enable an assessment
of the contribution of trees to the natural water cycle in situations similar to this
environment.
Hydrometric analysis for each nested watershed will be applied and results are expected
to show threshold values of rainfall for runoff generation and the contribution of groundwater
(baseflow) to the river flow and vice versa. Relations between geology, morphology and
climate will also be revealed. Rainfall and runoff data are currently available from two
stations, Panagia bridge (438 m) and Platanistasa (780 m). Results show a linear relation
between the daily runoff of the two stations. The relatively higher runoff in Platanistasa, as
compared to Panagia bridge, is probably due to the steep slopes and the higher rainfall rates.
Baseflow occurring at the end of the rain season indicate that the fractures in the geologic
formations fill up during the rainy season and discharge during the end of the season. During
the summer period, even when rainfall events occur, there is very little or no runoff
generation. |
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