Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 4.936 IF 4.936
  • IF 5-year value: 5.615 IF 5-year
    5.615
  • CiteScore value: 4.94 CiteScore
    4.94
  • SNIP value: 1.612 SNIP 1.612
  • IPP value: 4.70 IPP 4.70
  • SJR value: 2.134 SJR 2.134
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 107 Scimago H
    index 107
  • h5-index value: 63 h5-index 63
Volume 19, issue 7 | Copyright
Hydrol. Earth Syst. Sci., 19, 2971-2979, 2015
https://doi.org/10.5194/hess-19-2971-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 01 Jul 2015

Research article | 01 Jul 2015

Analyses of uncertainties and scaling of groundwater level fluctuations

X. Y. Liang1,2 and Y.-K. Zhang1,2,3 X. Y. Liang and Y.-K. Zhang
  • 1Center for Hydrosciences Research, Nanjing University, Nanjing, Jiangsu 210093, P. R. China
  • 2School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210093, P. R. China
  • 3Department of Geoscience, University of Iowa, Iowa City, Iowa 52242, USA

Abstract. Analytical solutions were derived for the variance, covariance, and spectrum of groundwater level, h(x, t), in an unconfined aquifer described by a linearized Boussinesq equation, with random source/sink and initial and boundary conditions. It was found that in a typical aquifer, the error in h(x, t) at an early point in time is mainly caused by the random initial condition, and the error reduces as time progresses to reach a constant error at a later time. The duration for which the effect of the random initial condition is significant may be a few hundred days in most aquifers. The constant error in h(x, t) at a later time is due to the combined effects of the uncertainties in the source/sink and flux boundary: the closer to the flux boundary, the larger the error. The error caused by the uncertain head boundary is limited to a narrow zone near the boundary and remains more or less constant over time. The aquifer system behaves as a low-pass filter which filters out high-frequency noises and keeps low-frequency variations. Temporal scaling of groundwater level fluctuations exists in most parts of a low permeable aquifer whose horizontal length is much larger than its thickness, caused by the temporal fluctuations of areal source/sink.

Publications Copernicus
Download
Short summary
The error or uncertainty in head, obtained with an analytical or numerical solution, at an early time is mainly caused by the random initial condition. The error reduces with time, later reaching a constant error. The constant error at a later time is mainly due to the effects of the uncertain source/sink. The error caused by the uncertain boundary is limited to a narrow zone. Temporal scaling of head exists in most parts of a low permeable aquifer, mainly caused by recharge fluctuation.
The error or uncertainty in head, obtained with an analytical or numerical solution, at an early...
Citation
Share