Investigation and comparison of one-dimensional (1-D) analytical models prediction for salt intrusion condition in two selected estuaries

• Published in: Marine georesources & geotechnology Vol. 38; no. 3; pp. 374 - 384
• Main Authors: Haddout, S., Priya, K. L., Adarsh, S.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 15-03-2020; Taylor & Francis Ltd
• Subjects: analytical solutions; Ashtamudi estuary (India); Bathymeters; Bathymetry; Bouregreg estuary (Morocco); Damping; Dimensional analysis; Distribution; Estuaries; Estuarine dynamics; Exponential functions; Intrusion; Mathematical analysis; Mathematical models; Parameterization; Salinity; Salinity effects; Salt-intrusion; Van der Burgh coefficient (K)
• ISSN: 1064-119X; 1521-0618
• DOI: 10.1080/1064119X.2019.1567632

In this paper, two analytical models used worldwide to assess salinity variation in alluvial estuaries are applied to the Ashtamudi estuary, a Ramsar site, southwest coast of India; and Bouregreg estuary, in northwest part of Morocco. The estuaries' bathymetry is described by an exponential function. Both models are quite similar and use a predictive equation for the dispersion in the estuary mouth (D
0
). The major difference between the two models is the use of the constant value of K = 0.5 for the Van der Burgh coefficient (K) and the introduction of the correction factor ζ, which is a function of damping (δ) and shape (γ). The performance of these two models was evaluated by comparing their results with field measurements; this revealed that both analytical models apply well to both the estimation of salinity distribution and the prediction of salt intrusion in the Ashtamudi and Bouregreg estuaries (Ashtamudi: RMSE = 0.60-1.22 ppt; Bouregreg: RMSE = 0.92-2.71 ppt). One model agrees more with the field measurements of salinity distribution along the estuaries axis; the second underestimate and overestimate some values of salinity distribution along the estuaries. Possibly, the constant value of K = 0.5 for the Van der Burgh coefficient (K) has applicability limits for the estuaries under tidal conditions. The specifying of the parameterization may be a field of research.