Publication Date:
2017-04-04
Description:
Groundwater contamination by nitrate and other nutrients is a major problem throughout the world, often
occurring as the result of anthropogenic activities, lack of management, and over-exploitation of groundwater
resources. In the last fewdecades in the majority of the Italian regions, the nitrate concentrations in groundwater
have dramatically increased, mainly as a consequence of the large-scale agricultural application of manure and
fertilizers. This excessive use of chemicals and fertilizers increases the risk of surface and groundwater pollution
fromdiffuse sources, which have an important impact on human health and the environment. Sicily is located in
the central Mediterranean, the total area of the island is 25,711 km2, with more than 5 million inhabitants. The
terrain of inland Sicily is mostly hilly and intensively cultivated wherever it was possible, nitrate vulnerable
zone about 40% of flat areas and 5.37% of total. The test site is located in Canicattì (central Sicily); the current
land use (grape, olive and almond cultivation) constitutes the main source of groundwater pollution.
In order to investigate the effect of over-farming on groundwater quality and to indentify an appropriate
methodology for pollution risk management, we have carried out a comparative study on the potential risk of
contamination from nitrate of agricultural origin, according to the conventional parametrical methods used in
Europe; the IPNOA parametric model (agricultural nitrates hazard index) method combined with the SINTACS
and DRASTIC intrinsic aquifer vulnerabilitymethods. All parameters used in this risk assessment were prepared,
classified, weighed, and integrated in a GIS environment. For calibrating the models and optimizing and/or
weighing the examined factors, the modeling results were validated by comparing them with groundwater
quality data, in particular nitrate content, and with census data fromthe potential pollution sources. The criterion
for checking this method was the correlation coefficient of each model with the nitrate concentration in the
groundwater. A relative coincidence of a high nitrate concentration and risk mapping was observed, but this
correlation was only significant using the SINTACS method. In fact, the final risk maps show significant
differences in risk quality assessment; the DRASTIC model values show an over-evaluation of the real contest.
In conclusion, the SINTACS parametric method appears to be the most suitable for constructing a relevant risk
map of the contamination of these aquifers, which are considered to be typical of the Mediterranean region for
their hydrogeological and hydrochemical features
Description:
Published
Description:
89–100
Description:
6A. Monitoraggio ambientale, sicurezza e territorio
Description:
JCR Journal
Description:
restricted
Keywords:
Groundwater vulnerability assessment
;
SINTACS
;
DRASTIC
;
Nitrate risk map
;
01. Atmosphere::01.01. Atmosphere::01.01.03. Pollution
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
