Study on aquifer hydraulic properties using tidal response method for future groundwater development
The hydraulic properties of an island’s aquifers were studied using a tidal response method. Groundwater is the principal water resource on the studied island, and the investigations of the aquifer for future groundwater development are ongoing. The method consists of three parts: observations of groundwater levels at paired near-shore and relatively inland sites affected by the same ocean tide, decompositions of the collected groundwater time series to yield isolated tidal components, and application of basic formulas describing propagation of groundwater-level oscillations in aquifers for determining hydraulic parameters. The observations require only auto-logging groundwater-level meters that are commonly used these days. Employed were two decomposition techniques that are easy to implement using only the built-in functions of spreadsheet software. Digital high-pass filtering was used to separate the tidal components of semidiurnal and diurnal periods from longer-period components prior to the following isolation of tidal constituents. Basic formulas for the Fourier transform were used to isolate one tidal constituent with a specific period. The isolation of one tidal constituent helps to reduce errors in the hydraulic parameter calculations based on formulas using the amplitude attenuation and phase shift of sinusoidal oscillations of the groundwater level. The calculation of aquifer hydraulic parameters can also be done directly on a spreadsheet. The derived aquifer hydraulic parameters compared well with those that were previously reported based on a pumping test conducted on the same island. The results are now used as a basis for further investigation of sustainable groundwater development on the island.
KeywordsCoastal aquifer Tidal propagation Time series decomposition Aquifer properties Groundwater development
The authors are grateful to the Land Improvement General Office and successive Officers for Policy Planning in the Land Improvement Division of the Okinawa General Bureau, Cabinet Office of Japan, for their support and collaboration. Thanks are also to local government officials and the residents of Tarama Island for their understanding and cooperation in the field study. This work was partially supported by JSPS KAKENHI Grant Number JP17K08011.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Ferris JG (1963) Cyclic water-level fluctuations as a basis for determining aquifer transmissibility. In: Bental R (comp) Methods of determining permeability, transmissibility and drawdown, US Geological Survey Water Supply Paper 1536-I, pp 305–318Google Scholar
- Imai R, Ohzeki M, Iryu Y (2013) Geologic ages of the Tarama Sandstone in the Tarama-jima, based on calcareous nannofossil biostratigraphy (in Japanese). Abstracts of the 120th Annual Meeting of the Geological Society of Japan, R5-P-25Google Scholar
- Japan Meteorological Agency (2017) http://www.data.jma.go.jp/obd/stats/etrn/view/nml_amd_ym.php?prec_no=91&block_no=1491&year=&month=&day=&view=. Accessed 23 Dec 2018
- Merritt ML (2004) Estimating hydraulic properties of the Floridan aquifer system by analysis of earth-tide, ocean-tide, and barometric effects, Collier and Hendry Counties, Florida. US Geological Survey Water-Resources Investigations Report 03-4267Google Scholar
- Nielsen P (1990) Tidal dynamics of the water table in beaches. Water Resour Res 26(9):2127–2134Google Scholar
- Oga H, Furukawa H, Ogura I, Nishida T (1974) Groundwater of Tarama Island, Okinawa Prefecture (in Japanese). Abstracts of the 81st Annual Meeting of the Geological Society of Japan, 368Google Scholar
- Ohzeki M, Imai R, Takayanagi H, Iryu Y (2014) Stratigraphy and geologic age of the Ryukyu Group on Tarama-jima, Ryukyu Islands, Japan (in Japanese). Abstracts of the 121st Annual Meeting of the Geological Society of Japan, R5-P-19Google Scholar
- Shirahata K, Ishida S, Yoshimoto S, Tsuchihara T (2014) New simple method for estimating hydraulic properties of a freshwater-lens aquifer by analysis of tidal groundwater fluctuations (in Japanese with English summary). Tech Rep Natl Inst Rural Eng 215:141–154Google Scholar
- Shirahata K, Yoshimoto S, Tsuchihara T, Ishida S (2017b) Estimation of aquifer hydraulic parameters by analysis of groundwater-level time-series in coastal area (in Japanese). Geotech Eng Mag 65(9):24–25Google Scholar
- Smith AJ, Hick WP (2001) Hydrogeology and aquifer tidal propagation in Cockburn Sound, Western Australia. CSIRO Land and Water Technical Report 6/01Google Scholar
- Todd DK (ed) (1980) Groundwater levels and environmental influences. In: Groundwater hydrology, 2nd edn. Wiley, New York, pp 218–286Google Scholar
- Urish DW (1980) Asymmetric variation of Ghyben-Herzberg lens. J Hydraul Div Proc Am Soc Civil Eng 106(7):1149–1158Google Scholar
- Yamada S, Yonahara N, Sobue H (2009) The Quaternary coral reef complex deposits (Ryukyu Group) and hydrogeologic features on Tarama-jima, Okinawa Prefecture, Japan (in Japanese). Abstracts of the 116th Annual Meeting of the Geological Society of Japan, 83(O-91)Google Scholar
- Yazaki K (1977) Geology of the Taramashima District (in Japanese with English abstract). Quadrangle Series, Scale 1: 50,000, Miyako-jima (19) No. 5, Geological Survey of JapanGoogle Scholar