Long-term trend and fluctuations of karst spring discharge in a Mediterranean area (central-southern Italy)

Abstract

Karst springs in central-southern Italy are largely exploited for the human consumption since the Roman Times and currently feed some tens of millions inhabitants with tap water of high quality. Unlike other karst springs, they are characterized by a steady rate during the year with modest seasonal variability. However, the effects of climate changes are being strongly perceived in central and southern Italy as in the rest of the Mediterranean basin, and groundwater is obviously also affected. In this paper, we analyze the discharge time series of some important karst springs in the region, evaluating the trends and fluctuations in relation to rainfall regime, on a yearly time scale. The aim is to evaluate the response of these large karst aquifers in the Mediterranean area to the recharge input variation. The role of the North Atlantic Oscillation has also been considered. Trends and fluctuations have been highlighted by n-years moving average and transforming the time series by the Rescaled Adjusted Partial Sum. The results show that a drop in the discharge has occurred since 1987, with reductions ranging from 15 up to 30 %, although this negative trend is now possibly attenuating or even reversing. As a final remark, the spring discharge of the large karst aquifers in central-southern Italy can be assumed as a robust indicator for climate changes as it integrates the effects of precipitation and temperature variation in time and space. © 2014, Springer-Verlag Berlin Heidelberg

Classification of karst springs for flash-flood-prone areas in western Turkey

“…In other words, the same amount of rainfall does not recharge aquifers as in the past because of change in rainfall intensity and its type as stated by Fiorillo et al (2015b) who explained this response by an increase in evapotranspiration due to an increase in temperature. Unlike other aquifers, vertically oriented karst features collect and quickly transport water from the surface to the underground fluvial system.…”

“…A more important reason, particularly in karst aquifers dominated by point infiltration, is the fast response of the aquifer to heavy rainfall that is expected to become more frequent in the future. This can be linked to the climate change, for which spring discharge is found to be a robust indicator (Fiorillo et al, 2015b).…”

“…The annual effective infiltration of the Gradole catchment in Croatia is between 36 and 76 % (Bonacci, 2001), while it is between 60 and 90 % for the mountainous karst regions in Switzerland (Malard et al, 2016). Similarly, in the Maiella aquifer in Italy, it is 900 mm (62 % of 1450 mm of total annual rainfall) (Fiorillo et al, 2015b).…”

Microbial mats as shelter microhabitat for amphipods in an intermittent karstic spring

“…Karst spring discharges reflect periods of poor or abundant precipitations due to specific recharge conditions and the locally prevalent climate regime (Bonacci, 2015;Fiorillo et al, 2015). In such conditions streamflow regime is recognized as the principal variable affecting the success and distribution of aquatic biota (Meyer and Meyer, 2000;Meyer et al, 2003;Konrad et al, 2008).…”

Water-table and discharge changes associated with the 2016–2017 seismic sequence in central Italy: hydrogeological data and a conceptual model for fractured carbonate aquifers

“…Fractures and karst conduits allow for fast vertical flow in the vadose zone, while the large thickness of the saturated zone facilitates a steady flow towards the basal springs that show outstandingly high and steady discharge (Petitta 2009;Amoruso et al 2014;Fiorillo et al 2015). …”