TY - JOUR
T1 - Tidal fluctuations in a multi-unit coastal aquifer
AU - Ratner-Narovlansky, Y.
AU - Weinstein, Y.
AU - Yechieli, Y.
N1 - Funding Information: This paper is dedicated to the memory of Haim Hemo, whose assistance in the field was invaluable, and sadly passed away during the preparation of this manuscript. We wish to express our gratitude to Yehuda Shalem, Iyad Swaed, Halel Lutsky, and Adi Tal, who helped with the field work. We also thank Elad Levanon and Steve Brenner for their assistance with analyzing the time series data. This project was supported by the Israel Water Authority [grant number 4500962408] and by MERC USAID [grant number M29-073 ]. Appendix A Publisher Copyright: © 2019 Elsevier B.V.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - Groundwater tidal fluctuations were studied in a multi-layered sandy coastal aquifer at Dor Bay, Israel, 35 m from shore. The aquifer at the site is ca. 50 m thick, and it consists of a superficial phreatic unit, underlain by two confined units, separated by 1–3 m thick clay layers. While the top of the deep unit is at 30 m below sea level, the top of the intermediate unit is irregular, and it is exposed in a nearby onshore ridge, as well as in the bay. The phreatic unit showed negligible tidal amplitudes, while the two deeper units showed relatively strong amplitudes, with those in the deeper unit exceeding those in the shallow unit (4-month average Agw/Asw of 0.72 and 0.53). Using Li and Jiao's (2001) solution, we showed that the deeper unit is in hydraulic contact with the sea at 100–400 m from shore, which should be due to the termination or breaching of the deeper clay. This is probably the result of a buried ridge, similar to the submerged calcareous sandstone ridge that exists today in the same location. The weaker amplitudes in the intermediate unit are not in accordance with its closer to shore exposure. We suggest that this is a consequence of the nearby onshore exposure of this unit, which suppresses the tidal signal.
AB - Groundwater tidal fluctuations were studied in a multi-layered sandy coastal aquifer at Dor Bay, Israel, 35 m from shore. The aquifer at the site is ca. 50 m thick, and it consists of a superficial phreatic unit, underlain by two confined units, separated by 1–3 m thick clay layers. While the top of the deep unit is at 30 m below sea level, the top of the intermediate unit is irregular, and it is exposed in a nearby onshore ridge, as well as in the bay. The phreatic unit showed negligible tidal amplitudes, while the two deeper units showed relatively strong amplitudes, with those in the deeper unit exceeding those in the shallow unit (4-month average Agw/Asw of 0.72 and 0.53). Using Li and Jiao's (2001) solution, we showed that the deeper unit is in hydraulic contact with the sea at 100–400 m from shore, which should be due to the termination or breaching of the deeper clay. This is probably the result of a buried ridge, similar to the submerged calcareous sandstone ridge that exists today in the same location. The weaker amplitudes in the intermediate unit are not in accordance with its closer to shore exposure. We suggest that this is a consequence of the nearby onshore exposure of this unit, which suppresses the tidal signal.
KW - Confined aquifer
KW - Phreatic aquifer
KW - Tidal fluctuations
UR - http://www.scopus.com/inward/record.url?scp=85074141747&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.jhydrol.2019.124222
DO - https://doi.org/10.1016/j.jhydrol.2019.124222
M3 - Article
SN - 0022-1694
VL - 580
JO - Journal of Hydrology
JF - Journal of Hydrology
M1 - 124222
ER -