Salinity Intrusion Model Research Articles

Development of salinity intrusion model (Munaf Q. 2019) In the Shatt Al-Arab River

Mathematical model (Munaf Q. 2019) was developed to predict the intrusion of salt into the Shatt Al-Arab River, which addresses the problem of the difficulty of measurements and prediction of the level of salinity along the Shatt Al-Arab River during the measurement period and in a very short time, where it is possible to identify the level of salinity along the Shatt Al-Arab River when it changes at the estuary. In this article, a mathematical model was used with an automatic computing system to predict the penetration of the salt intrusion into the Shatt Al-Arab, based on the development of a previous mathematical model. The results obtained through the application of the model showed that there is a great convergence between the results at a high level and at most of the stations under study (Al-Fadaqhiyah, Seyhan, Basrah, Al-Hartha) for the field-measured values with the theoretical values respectively, as follows: 27-26 ppt., 2.6-2.9 ppt., 1.85-1.96 ppt., 0.86-0.92 ppt., when the flow is 50m3/sec. When the flow is 5m3/sec, the results are as follows: 30.4-30.2 ppt., 25.3-25.1 ppt., 11.4-12.6 ppt., 1.50-1.97 ppt., Therefore the adoption of this mathematical model can be enhanced to predict the penetration of the salt as a result of any situation that may occur at any time along the Shatt Al-Arab River. The reason for using mathematical models is because it is an easy, cheap and fast way of obtaining the desired results to address some of the problems that occur for many reasons, the most important of which are direct events that may occur as a result of a sudden change in the variables dependent on them.

A predictive model for salt intrusion in estuaries applied to the Muthupet estuary (India) and Bouregreg estuary (Morocco)

ABSTRACT In this paper, two 1D salt intrusion models, i.e. the steady-state and unsteady-state salinity intrusion model are used to assess the salt intrusion distribution in Muthupet estuary, a Ramsar site in Tamil Nadu, India; and Bouregreg estuary, in north-western part of Morocco. Results indicate that the steady-state salt intrusion model performs well to salinity observations especially during post-monsoon period (Indian estuary). Despite the fact that the high-salinity values observed during pre-monsoon period at a distance of 5 km to 7.5 km from the mouth are badly represented by the steady-state model it is a good indicator for the salt intrusion length. Additionally, this research shows that it is likely that an additional source of salt is causing the increase in salinity values at Lagoon reach and that the unsteady-state salt intrusion is able to represent this. On the other hand, a normal estuary is presented in this paper, for study comparison, i.e. Bouregreg estuary. The steady-state salt intrusion model outperformed the model results of the Indian estuary and is better to predict salt intrusion length and salinity variation along the Bouregreg estuary.

Prediction of salinity intrusion in the sheltered estuary of Terengganu River in Malaysia using 1-D empirical intrusion model

Generally one dimensional (1-D) empirical salinity intrusion model is limited to natural alluvial estuary. However, this study attempts to investigate its ability to model a sheltered alluvial estuary of the Terengganu River in Malaysia. The constructed breakwater at the mouth of the river shelters the estuary from direct influence of the open sea. The salinity density along the estuary was collected during the wet and dry seasons for scenarios before and after the constructed breakwater. Moreover, the freshwater discharges, tidal elevations and bathymetry data were also measured as model inputs. A good fit was demonstrated between simulated and observed variables, namely salinity distribution and intrusion length for both scenarios. Thus, the results show that 1-D empirical salinity model can be utilized for sheltered estuarine condition at the Terengganu Estuary, but with an appropriate determination of an initial point. Furthermore, it was observed that the salinity intrusion in the study area is largely dependent on the freshwater discharge rather than tidal elevation fluctuations. The scale of the salinity intrusion length in the study area is proportional to the river discharge of the–1/2 power. It was appeared that the two lines of the 1-D empirical salinity model and discharge power based equation fitted well to each other, with the average predicted minimum freshwater discharge of 150 m3/s is going to be required to maintain acceptable salinity levels during high water slack (HWS) near the water intake station, which is located at 10.63 km from river mouth.

Hydrodynamic and Salinity Intrusion Model in Selangor River Estuary

A multi-dimensional hydrodynamic and transport model has been used to develop the hydrodynamic and salinity intrusion model for Selangor River Estuary. Delft3D-FLOW was applied to the study area using a curvilinear, boundary fitted grid. External boundary forces included ocean water level, salinity, and stream flow. The hydrodynamic and salinity transport used for the simulation was calibrated and confirmed using data on November 2005 and from May to June 2014. A 13-day period for November 2005 data and a 6-day period of May to June 2014 data were chosen as the calibration and confirmation period because of the availability of data from the field-monitoring program conducted. From the calibration results, it shows that the model was well suited to predict the hydrodynamic and salinity intrusion characteristics of the study area.

Analytical estimates of hydraulic parameters for an urbanized estuary – Flushing Bay

Summary Prediction of water quality improvements in urban estuaries is an urgent priority for decision making about alternative mitigation measures, especially in the context of changing pollutant loadings and freshwater discharges. Flushing Bay, an embayment of the New York–New Jersey Harbor Estuary, is a “short” estuary (a special class of coastal plain estuary with specific geometric characteristics), in which source loading is changing and little is known about resultant mixing processes and characteristics. First-order values of longitudinal dispersion coefficient, tidal excursion and tidal prism for this estuary have been estimated from non-synoptic salinity data using an adaptation of a one-dimensional theoretical salinity intrusion model. Results indicate that ranges of longitudinal dispersion coefficient are highly dependent on estimates of groundwater discharge, and the spatial distribution of salinity and dispersion coefficient values is most sensitive to conditions at low water slack (LWS). These findings represent a starting point for further investigation of either groundwater discharge to the bay using numerical modeling or field studies of longitudinal dispersion coefficient and mixing using sophisticated tracer methods.

Salinity‐Intrusion Forecasting System for Gambia River Estuary

A methodology is presented for forecasting the response of salinity movement in a tidal estuary to seasonal rainfall and freshwater inflows. The forecasting procedure uses linked stochastic and deterministic models to provide information to aid decision makers. These models include: (1) Multisite stochastic rainfall data generation models used to generate long‐term synthetic records of 10‐day rainfall for stations in the upper river basin; (2) a deterministic rainfall‐runoff multiple regression model used to compute a long‐term record of 10‐day mean flow on the river's main stem based on real‐time initial flow and rainfall data and synthetic rainfall records; and (3) a one‐dimensional finite difference salinity intrusion model used to compute the movement of the 1 part per thousand (ppt) salinity level for each year of the computed long‐term flow record. A cumulative probability distribution of the maximum salinity flushing distances along the estuary is developed as a tool for decision makers. The Gambia estuary in West Africa was used as a case study.

A one-dimensional model for salinity intrusion in alluvial estuaries

A salinity intrusion model for well-mixed alluvial estuaries is developed. The parameters are schematized in such a way that the amount of field work in gathering data on estuary geometry and tide is considerably reduced. The determining factor in the geometry is found to be the variation of width in the estuary. This relationship appears to obey an exponential law. The depth is found to remain fairly constant and does not necessarily have to be measured. A stationary and a non-stationary model are developed. The stationary model may be applied, using a pocket calculator. In many cases however, where the stationary model may not be used the non-stationary model may be applied. Application of the model is demonstrated on several alluvial estuaries.

C & D Canal Effect on Salinity of Delaware Estuary

Analysis of the effect of C & D Canal on the salinity intrusion in the Delaware Estuary is described. Two separate mathematical models are used: MIT-Dynamic Network Model and MIT-Transient Salinity Intrusion Model. Emphasis is put on the investigation of simulated responses in the Delaware, rather than the Canal. The primary objective of the study is the investigation of salinity distribution in the Delaware under different forcing functions. MIT-DNM application reveals the behavior of a coupled Canal/Delaware system under natural boundary conditions specified at the Chesapeake Bay, Capes May and Henlopen and at the head of tide at Trenton. MIT-TSIM application shows temporal and spatial salt distribution in the Delaware with salt and net flow condition specifications in the Canal. The results of these simulations indicate that salinity in the Delaware Estuary is appreciably affected by the dynamics of the Canal. However, the Canal has little discernible effect on the hydrodynamics of the Delaware.

Identification in nonlinear, distributed parameter water quality models

Systematic and efficient numerical algorithms are developed and applied to the identification of unknown functional parameters in nonlinear estuarine water quality models based on input‐output measurements. As an illustration of the methodology the longitudinal dispersion coefficient is identified from an intratidal, time‐varying, variable area, salinity intrusion model by using both simulated data and actual data from the Delaware River estuary. A comparison among three proposed algorithms through extensive simulation research shows that Marquardt's algorithm emerged as the most efficient one. Effects of noise content and the number of data measurement locations on parameter sensitivity are investigated. Actual monitored salinity data for 3 days in September 1965 are tested in the saline portion of the Delaware River estuary. The spatial variation of the longitudinal dispersion coefficient for this period is estimated. The results obtained indicate that the methodology is generally applicable and it represents a different and supplementary alternative to the methods based on analytical predictions and empirical correlations.