Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in Recharge
The temperature distribution of shallow sectors of coastal aquifers are highly influenced by the atmospheric temperature and recharge. However, geothermal heat or vertical fluxes due to the presence of the saline wedge have more influence at deeper locations. In this study, using numerical models th...
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MDPI AG
2022-09-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/14/18/2807 |
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| author | Angela M. Blanco-Coronas Maria L. Calvache Manuel López-Chicano Crisanto Martín-Montañés Jorge Jiménez-Sánchez Carlos Duque |
| author_facet | Angela M. Blanco-Coronas Maria L. Calvache Manuel López-Chicano Crisanto Martín-Montañés Jorge Jiménez-Sánchez Carlos Duque |
| author_sort | Angela M. Blanco-Coronas |
| collection | DOAJ |
| description | The temperature distribution of shallow sectors of coastal aquifers are highly influenced by the atmospheric temperature and recharge. However, geothermal heat or vertical fluxes due to the presence of the saline wedge have more influence at deeper locations. In this study, using numerical models that account for variable density, periodic oscillations of temperature have been detected, and their origin has been attributed to the influence exerted by recharge and tides. The combined analysis of field data and numerical models showed that the alternation of dry and wet periods modifies heat distribution in deep zones (>100 m) of the aquifer. Oscillations with diurnal and semidiurnal frequencies have been detected for groundwater temperature, but they show differences in terms of amplitudes and delay with electrical conductivity (EC). The main driver of the temperature oscillations is the forward and backward displacement of the freshwater–saltwater interface, and the associated thermal plume generated by the upward flow from the aquifer basement. These oscillations are amplified at the interfaces between layers with different hydraulic conductivity, where thermal contours are affected by refraction. |
| first_indexed | 2024-03-09T22:12:53Z |
| format | Article |
| id | doaj.art-fcf3fab342c5486bb26f53686594d452 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-09T22:12:53Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-fcf3fab342c5486bb26f53686594d4522023-11-23T19:30:22ZengMDPI AGWater2073-44412022-09-011418280710.3390/w14182807Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in RechargeAngela M. Blanco-Coronas0Maria L. Calvache1Manuel López-Chicano2Crisanto Martín-Montañés3Jorge Jiménez-Sánchez4Carlos Duque5Departamento de Geodinámica, Universidad de Granada, Avenida Fuente Nueva s/n, 18071 Granada, SpainDepartamento de Geodinámica, Universidad de Granada, Avenida Fuente Nueva s/n, 18071 Granada, SpainDepartamento de Geodinámica, Universidad de Granada, Avenida Fuente Nueva s/n, 18071 Granada, SpainCN-Instituto Geológico y Minero de España (IGME-CSIC), Unidad de Granada, Urb. Alcázar del Genil, 4 Edificio Zulema, Bajo, 18006 Granada, SpainCN-Instituto Geológico y Minero de España (IGME-CSIC), Unidad de Granada, Urb. Alcázar del Genil, 4 Edificio Zulema, Bajo, 18006 Granada, SpainDepartamento de Geodinámica, Universidad de Granada, Avenida Fuente Nueva s/n, 18071 Granada, SpainThe temperature distribution of shallow sectors of coastal aquifers are highly influenced by the atmospheric temperature and recharge. However, geothermal heat or vertical fluxes due to the presence of the saline wedge have more influence at deeper locations. In this study, using numerical models that account for variable density, periodic oscillations of temperature have been detected, and their origin has been attributed to the influence exerted by recharge and tides. The combined analysis of field data and numerical models showed that the alternation of dry and wet periods modifies heat distribution in deep zones (>100 m) of the aquifer. Oscillations with diurnal and semidiurnal frequencies have been detected for groundwater temperature, but they show differences in terms of amplitudes and delay with electrical conductivity (EC). The main driver of the temperature oscillations is the forward and backward displacement of the freshwater–saltwater interface, and the associated thermal plume generated by the upward flow from the aquifer basement. These oscillations are amplified at the interfaces between layers with different hydraulic conductivity, where thermal contours are affected by refraction.https://www.mdpi.com/2073-4441/14/18/2807geothermal gradientsaltwater intrusiontemperature fluctuationstidal influencegroundwater rechargeclimate change |
| spellingShingle | Angela M. Blanco-Coronas Maria L. Calvache Manuel López-Chicano Crisanto Martín-Montañés Jorge Jiménez-Sánchez Carlos Duque Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in Recharge Water geothermal gradient saltwater intrusion temperature fluctuations tidal influence groundwater recharge climate change |
| title | Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in Recharge |
| title_full | Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in Recharge |
| title_fullStr | Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in Recharge |
| title_full_unstemmed | Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in Recharge |
| title_short | Salinity and Temperature Variations near the Freshwater-Saltwater Interface in Coastal Aquifers Induced by Ocean Tides and Changes in Recharge |
| title_sort | salinity and temperature variations near the freshwater saltwater interface in coastal aquifers induced by ocean tides and changes in recharge |
| topic | geothermal gradient saltwater intrusion temperature fluctuations tidal influence groundwater recharge climate change |
| url | https://www.mdpi.com/2073-4441/14/18/2807 |
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