ALBERT

Description: The use of geothermal energy resources to support anthropogenic activities have a long-lasting tradition, renewed in recent decades with the increasing use of low enthalpy geothermal energy (LEG) with combined systems of heat pumps and geothermal exchange, exploiting the enormous thermal capacity and very low temperature variability of subsoil, including rocks and water. The further potential global increase of LEG use could be enormous, although LEG is already the main geothermal energy sources in Europe, contributing significantly to reach 2030 UN sustainable development goals (SDGs) on renewable energy resources, as a further leg to support all necessary efforts for these scopes. This research pursues LEG spreading improving knowledge on limitations of guidelines, technical regulations and/or laws, briefly rules, especially in terms of potential risks or limitations due to environmental constrains or natural phenomena. A global documentary research, including scientific articles, books, technical reports from qualified institutions, technical standards, guidelines, regulations, and laws, was realized with three different groups of keywords. A total of 161 documents were selected after some steps, including quality check. Identical English and Italian keyword sets were used to span from an international global scale to the complex local scale which characterizes the Italian experience. A complex sheet was filled in for each document, supporting data discussion, planned with a geographical criterion, from global to local. The system of rules resulted worldwide inhomogeneous and complex, with high differences from countries, nations or regions, also at local scale. The low quality or the absence of simple and careful “rules” emerged an important obstacle to LEG diffusion that can guarantee sustainability and the absence of natural risks. Main virtuous systems of rules were recognized as very useful to promote LEG spreading but these are still uncommon. The discussion of optimal experiences and the overview of potential natural risks due to LEG complete the paper.

Description: This Special Issue presents the work of 30 scientists of 11 countries. It confirms that the impacts of global change, resulting from both climate change and increasing anthropogenic pressure, are huge on worldwide coastal areas (and very particularly on some islands of the Pacific Ocean), with highly negative effects on coastal groundwater resources, widely affected by seawater intrusion. Some improved research methods are proposed in the contributions: using innovative hydrogeological, geophysical, and geochemical monitoring; assessing impacts of the changing environment on the coastal groundwater resources in terms of quantity and quality; and using modelling, especially to improve management approaches. The scientific research needed to face these challenges must continue to be deployed by different approaches based on the monitoring, modeling, and management of groundwater resources. Novel and more efficient methods must be developed to keep up with the accelerating pace of global change.

Description: 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.