Seawater Intrusion Proneness and Geophysical Investigations in the Metaponto Coastal Plain (Basilicata, Italy)

Abstract

The Metaponto coastal plain extends about 40 km along the Ionian coast, between the Sinni and Bradano Rivers (southern Italy). During the 20th century, the increases in modern irrigation systems, land reclamation works, the overexploitation of wells, and agricultural and industrial activities have deeply modified land use and groundwater availability and quality along the plain. These modifications negatively impacted the natural systems in terms of groundwater and soil salinization, magnifying the risks due to seawater intrusion. In this study, we explored the proneness to seawater intrusion, testing a multidisciplinary approach based on hydrochemical and geophysical investigations. A significant portion of the coastal plain was selected for this purpose. A set of 49 groundwater samples was analyzed to define the chemical characteristics of the water and geoelectrical measurements were recorded along three long profiles. The geoelectrical surveys showed in detail the aquifer bottom pattern where it is deeply incised by paleovalleys, defining the main hydrostratigraphic features, as it is necessary to prevent seawater intrusion worsening. The hydrochemical data highlighted areas with higher seawater intrusion proneness. The acquired measurements show the high proneness to seawater intrusion, especially where the aquifer bottom is very deep below the sea level, also far from the coast, and the relevance of the detailed knowledge of the aquifer bottom in supporting any kind of management.

Groundwater Resources Management: Reconciling Demand, High Quality Resources and Sustainability

“…This is the case for many coastal plains, in which merging geophysical and geochemical surveys can be a basic approach to management. Muzzillo et al [16] assess the proneness to seawater intrusion, testing a multidisciplinary approach based on hydrochemical and geophysical investigations of a coastal plain located along the Ionian coast of southern Italy. This coastal plain, as is observed to be widespread at a global scale, has suffered relevant anthropogenic modifications during the 20th century, with the effects of groundwater availability and quality degradation.…”

“…The second theme is focused on groundwater vulnerability assessments against external pollution, focusing on groundwater quality management [10][11][12][13]. The third theme explores the potentiality of geophysics tools supporting groundwater management in the case of coastal aquifers [14][15][16]. The fourth theme concerns problems associate with groundwater quantity [17][18][19][20].…”

Multi-Decadal Assessment of Soil Loss in a Mediterranean Region Characterized by Contrasting Local Climates

“…Arable lands are the main cover also in the centraleastern zone (Matera Hills), characterized by the so-called calanchi, i.e., badlands with bare clay hills strongly affected by erosional processes [59]. The Metaponto Plain, a strip of land overlooking the Ionian Sea, is the core of the specialized agriculture of Basilicata (fruit trees and orchards, see [60]) where salinization phenomena have threaten groundwater quality and soil productivity [61,62]. The peculiarity of Basilicata is the coexistence of the different and, in some ways, contrasting climates it encompasses: the temperate climates (Csa and Csb), the steppic climate (Bsk), and the Mediterranean mountain climates (Dsb and Dsb) characterizing some isolated mountainous areas of the Apennine Chain [63].…”

“…Medium-low values prevail in the forests of the western part of the region, while the Bradano Basin and the Metaponto Plain appear to be the less impacted by erosion phenomena due to topographic reasons, being composed of lowlands and areas with gentle slopes. These plain areas overlooking the Ionian Sea are affected by a type of erosion that cannot be assessed with the RUSLE model; coastal erosion affects the entire Ionian coast to a varying extent with soil loss and saline intrusion phenomena [62].…”

“…Medium-low values prevail in the forests of the western part of the region, while the Bradano Basin and the Metaponto Plain appear to be the less impacted by erosion phenomena due to topographic reasons, being composed of lowlands and areas with gentle slopes. These plain areas overlooking the Ionian Sea are affected by a type of erosion that cannot be assessed with the RUSLE model; coastal erosion affects the entire Ionian coast to a varying extent with soil loss and saline intrusion phenomena [62]. Looking at the differences of soil loss computed in the three time intervals , and 2021-2014, see Figure 7a-c), it is evident that the year 2004 exhibits the worst rates with positive difference found almost everywhere with respect to the year 1994 (Figure 7a).…”