Seawater intrusion in the Guanahacabibes Peninsula (Pinar del Rio Province, western Cuba): effects on karst development and water isotope composition

Integrating Hydrogeological and Microbiological Data and Modelling to Characterize the Hydraulic Features and Behaviour of Coastal Carbonate Aquifers: A Case in Western Cuba

“…For example ( Figure 6, box A), the upper cluster groups almost all the wells located in the central part of the study area as well as the water sample collected in the El Pesquero lagoon (LP) and seawater (sbc); this latter point is in agreement with the groundwater flow net, as shown in Figure 2. This clusterisation further supports the hypothesis of a hydraulic interconnection between the lagoon system and the surrounding groundwater, as suggested in function of the hydraulic head distribution and the previous isotopic and hydrochemical investigations [9].…”

“…From the methodological point of view, this study shows that the knowledge about mixing processes in this type of heterogeneous media can be further improved using multilevel sampling systems, to avoid possible misunderstandings due to intra-well mixing in fully screened wells. At the same time, based upon the results of this work and a previous study [9], the interdisciplinary characterization of the Guanahacabibes Peninsula carbonate aquifer further demonstrates the great effectiveness of approaches that merge hydrogeological, hydrochemical, isotopic and biomolecular investigations to understand the behaviour of complex systems.…”

“…The lagoons are fed by the Cuyaguateje River. The ingression of waters from El Pesquero lagoon to the surrounding groundwater is already described in [9] using isotopic and chemical investigations, and further supported by biomolecular ones (see hereafter).…”

“…This observation is in agreement with the more complex variation in chemical features observed within the saturated zone investigated in well 33. A detailed geochemical characterisation of these waters suggested [9] that the samples from well 33 showed Ca enrichment and a Mg, Na and K depletion compared with the curves representing binary mixing between seawater and freshwater or rainwater, on which the samples from well 18 are clustered. Moreover, the calcium excess and sulfate deficit observed in well 33 samples have been explained by additional calcium carbonate dissolution, probably occurring in the presence of bacterial reduction in organic-rich sediments.…”

“…At the study site, Peninsula de Guanahacabibes, Western Cuba (see Figure 1), hydrochemical and isotopic investigations were used in a previous paper [9] to analyse in detail the geochemical processes characterising the local interaction and mixing between rain-, surface-, ground-and seawater. The main aim of the present study was to test the efficacy of an experimental modelling approach, ranging from hydrogeology/geomorphology to microbiology, to better characterise both the hydraulic features and behaviour of a coastal carbonate aquifer, therefore acquiring useful information to prevent groundwater salinization.…”