Abstract
The Island of Ischia, one of the Italian active volcanoes, is a famous tourist resort for spa treatments. Spas are supplied by withdrawals from groundwaters which are characterized by a wide range of chemical compositions, salinity and temperature. In natural conditions, the hydrogeological system is recharged by rainfall and by deep fluids; the discharge is towards the sea and the springs. During the peak of the tourist season, when approximately 240 wells are operating simultaneously, a significant additional recharge of the aquifers derives from seawater and from upwelling increase in deep fluids. Although this does not compromise the availability of groundwater, the pumping often determines variation in composition and temperature of groundwater over time. Conversely, the maintenance of a stable quality of thermal waters represents one of the requirements for their therapeutic use in the spas. The study aims to establish game-theoretical modeling of the optimal sustainable exploitation of the groundwater resources of the island by competing users (spas) falling in the same flow tube of the aquifer. In the game the spas are the players, the strategy of a player consists of a fixed pumping rate and daily time durations of pumping, and the player’s utility or payoff is proportional to the total quantity of withdrawn thermal water in a given time period. A special constrained Pareto optimal strategy choice is obtained, considered as a cooperative solution of the game. Pareto optimality means that there is no other strategy choice that makes one player better off without making some other player worse off.
Highlights
Thermal waters are widely used all over the world as a resource for health, wellness and recreational tourism with important impact on global economy (Global Wellness Institute, 2017)
For the spa facilities falling in the area (Fig. 2), groundwater volumes required from the different plants were estimated, distinguishing volumes needed to fill the pools with thermal waters (VP) and those required for spa treatments (VF)
This study proposes a new approach to managing groundwater pumping from the volcanic aquifer of the Island of Ischia, an active hydrothermal system where numerous spas extract thermal waters that are significantly different in temperature, salinity and chemical compositions
Summary
Thermal waters are widely used all over the world as a resource for health, wellness and recreational tourism with important impact on global economy (Global Wellness Institute, 2017). The volcanic island of Ischia represents one of the few cases in the world where there is a very high concentration of groundwater withdrawals used for health, wellness and recreational tourism This is due to the presence of an active hydrothermal system which gives rise to a wide variety of groundwaters, very different in chemical composition (from calciumbicarbonate to alkali-chloride waters), salinity (from 1 to 42 g/L) and temperature (from 13 to 90 °C). The pumping from the numerous wells present in the coastal area significantly increases the recharge of the island with seawater intrusion and upwelling of deep fluids This does not compromise the availability of groundwater in quantitative terms, the pumping modulates the quality of the water captured by the wells often determining variation in composition and temperature of groundwater over time. A qualitative decay of the thermal waters can have a relevant economic impact, given that the European and Italian legislations establish that composition and temperature of thermal waters used for therapeutic purposes must remain constant over time (Piscopo et al, 2020a)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
