Orthotidal signal in the electrical conductivity of an inland river
- 16 Downloads
An orthotidal signal is a tidal component found in a streamwater parameter when there is no oceanic tidal input, i.e. when the streamwater monitoring point is located far inland and at high elevation. This study analyses various parameters of Cib River in Carpathian Mountains, Romania. This river receives water from a rich karst aquifer when crossing Cib Gorge. Streamwater level, temperature and electrical conductivity were measured in 270 days grouped in three time intervals of consecutive days. The measurements were done every 15 minutes in order to capture any significant periodic variation. The streamwater measurements were paired with air measurements and measurements done in a thermal spring. Solar semidiurnal oscillations were found in the streamwater electrical conductivity. In case study time series, selected based on their good signal to noise ratio, there are average semidiurnal oscillations of approximately 4 μS/cm, while the maximum amplitude rise up to 20 μS/cm. The semidiurnal peaks in water are generally in phase with the two atmospheric tide maxima, which are the cause of the studied phenomenon. The higher mineralisations of the thermal waters that rise from beneath the karst aquifer are the most probable cause of finding significant orthotides only in the electrical conductivity time series of the studied river.
KeywordsOrthotidal potamology Karst aquifer Thermal spring S2 Wavelet analysis
This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS – UEFISCDI, project number PN-II-RU-TE-2014-4-2900. Due to important field and laboratory work, Dumitru Mihăilă is to be considered, together with Andrei-Emil Briciu, as one of the principal authors.
- Briciu, A.-E., Mihăilă, D., Oprea-Gancevici, D. I., & Bistricean, P. I. (2017). Some aspects regarding the thermal water temperature of some sites in Baile Felix, Geoagiu-Bai and Harsova areas, Romania. SGEM2017 Conference Proceedings, 17(31), 601–608. https://doi.org/10.5593/SGEM2017/31/S12.075.Google Scholar
- Callede, J. (1977). Oscillations journalières du débit des rivières en l’absence de precipitations. Cahier ORSTOM, série Hydrologie, 14, 219–283.Google Scholar
- Chapman, S., & Lindzen, R. S. (1970). Atmospheric tides. Norwell, Mass: D. Reidel.Google Scholar
- Domenico, P. A., & Schwartz, F. W. (1998). Physical and chemical hydrogeology. New York: Wiley.Google Scholar
- Ingebritsen, S., Sanford, W., & Neuzil, C. (2006). Groundwater in geologic processes. Cambridge: Cambridge University Press.Google Scholar
- Johnson, B., Malama, B., Barrash, W., & Flores, A. N. (2013). Recognizing and modeling variable drawdown due to evapotranspiration in a semiarid riparian zone considering local differences in vegetation and distance from a river source. Water Resources Research, 49, 030–1039.Google Scholar
- Mantea, G., & Tomescu, C. (1986). Structura geologica a ariei centrale a Muntilor Metaliferi, zona Balșa-Ardeu-Cib (Geological structure of the central area of the Metaliferi Mountains, Balșa-Ardeu-Cib zone). Dări de Seamă ale Institutului de Geologie și Geofizică, 70-71(5), 129–148.Google Scholar
- Merritt, M. L. (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, 03–4267, 1–70.Google Scholar
- Orășeanu, I. (2016). Hidrogeologia carstului din Munții Apuseni (Karst hydrogeology of Apuseni Mountains). Oradea: Belvedere Press.Google Scholar
- Wesseling, J. (1959). Transmission of tidal waves in elastic artesian basins. Netherlands Journal of Agricultural Science, 7, 22–32.Google Scholar
- White, W.N. (1932). A method of estimating ground-water supplies based on discharge by plants and evaporation from soil: results of investigations in Escalante Valley. US Geological Survey Water Supplementary Paper, 659-A.Google Scholar