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| Titel |
The San Niccolo' experimental area for studying the hydrology of coastal Mediterranean peatlands |
| VerfasserIn |
Rudy Rossetto, Alessio Barbagli, Tiziana Sabbatini, Nicola Silvestri, Enrico Bonari |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111723
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| Publikation (Nr.) |
 EGU/EGU2015-11862.pdf |
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| Zusammenfassung |
| Starting from 1930, a large part of the Massaciuccoli Lake coastal area (Tuscany,
Italy) has been drained for agricultural purposes by a complex network of artificial
drains and pumping stations. In the drained areas, peat soils, with values of organic
matter up to 50% in some cases, are largely present (Pistocchi et al., 2012). As a
consequence of the human impact, environmental problems arose in the last 50
years:
i. the eutrophication status of the Massaciuccoli lake caused by nutrient enrichment (N, P)
in surface- and ground-water (Rossetto et al., 2010a);
ii. the subsidence (2-3 m in 70 years) of the lake bordering areas due to soil compaction
and mineralization (Rossetto et al., 2010b).
As a potential solution to improve water quality and to decrease soil organic matter
mineralization, a rewetted pilot experimental area of 15 ha with phyto-treatment
functionalities has been set up. This pilot, adequately instrumented, now constitutes
an open field lab to conduct research on the hydrology of coastal Mediterranean
peatlands.
Site investigation was performed and data on stratigraphy (from top on average: 1/2 m
thick peat layer, 1/3 m organic matter-rich silt, 1/3 m stiff blue-gray clay, up to 30 m
thick sand layer) and water (ground- and surface-water) quantity and quality were
gathered and related to both local and regional groundwater flows. The inferred
hydrological conceptual model revealed the pilot is set in a regional discharge area and the
ground-water dependent nature of the agro-ecosystem, with mixing of waters with different
origins.
The site has been divided in three different phyto-treatment systems:
a constructed wetland system, internally and externally banked in order to force
water flow to a convoluted pattern where Phragmites australis L. and Thypha
angustifolia L. constitute the sparse natural vegetation;
a vegetation filter system based on the plantation of seven different no-food crops
managed according to a periodic cutting and biomass harvesting (eg: Populus
spp., Salix spp., Arundo donax L., Miscanthus x giganteus ). The system is
crossed by a dense network of ditches supplying water to the crops through
lateral infiltration and partial submersion;
a wetland system consisting in a flooded area where the re-colonization of
spontaneous vegetation takes place.
The designed monitoring system includes sensors in surface- and ground-water. The
ground-water monitoring system consists of a set of 15 piezometer clusters. At each cluster
three piezometers (3 inch diameter, screened in the last 30 cm) are set at about 3 m, 2 m and 1
m depth to allow multilevel monitoring and sampling so to investigate a large part of the
aquifer and the relationships between the surface-water and ground-water systems. An
unsaturated pilot monitoring station has been designed and it will be set in operation to gain
information on infiltration and/or exfiltration processes and evapotranspiration. Ten sensors
for continuously monitoring groundwater head, temperature and electrical conductivity are in
operation.
Surface water are monitored by means of six gauging stations where sensors are
recording at least head, temperature and electrical conductivity. At four of them continuous
sampling takes place with a composite daily sample made up of four samples, each gathered
every six hours.
A complete hydrological monitoring protocol has been set in place starting by
meteorological data aquisition. As well as continuous monitoring with in-situ sensors and
composite sampling with automatic samplers, discrete monitoring on monthly basis takes
place. Main physico/chemical parameters (temperature, pH, dissolved oxygen, electrical
conductivity and redox potential) are routinely monitored. The experimental area is in
operation since December 2013.
Acknowledgements
The authors wish to thank the Consorzio 1 – Toscana Nord for technical support.
References
Pistocchi C., Silvestri N., Rossetto R., Sabbatini T., Guidi M., Baneschi I., Bonari E. &
Trevisan D. (2012) - A simple model to assess nitrogen and phosphorus contamination in
ungauged surface drainage networks: application to the Massaciuccoli Lake Catchment, Italy.
Journal of Environmental Quality 41, 544-53.
Rossetto,R., Basile, P., Cavallaro, E., Menichetti,S., Pistocchi, C., Sabbatini, T., Silvestri,
N. & Bonari, E. (2010a) - Phosphorous presence in groundwater from peat oxidation:
preliminary results from the Lake Massaciuccoli area (Italy). International Groundwater
Symposium I.A.H.R. Valencia (Spain).
Rossetto R., Basile P., Cannavò S., Pistocchi C., Sabbatini T., Silvestri N. & Bonari E.
(2010b) - Surface water and groundwater monitoring and numerical modeling of the southern
sector of the Massaciuccoli Lake basin (Italy). Rendiconti Online Società Geologica Italiana
11, 189-190. |
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