scholarly journals Controlling the Salt Wedge Intrusion in Shatt Al-Arab River by a Barrage

2021 ◽  
Vol 27 (12) ◽  
pp. 69-86
Author(s):  
Alaa Abdula Ali ◽  
Hayder A Al Thamiry
Keyword(s):  
Boundary Conditions ◽  
Water Discharge ◽  
Spring Tide ◽  
Water Levels ◽  
Salt Intrusion ◽  
Intrusion Prevention ◽  
Salt Wedge ◽  
Tigris River ◽  
Hydraulic Impact ◽  
Fresh Water Discharge

Shatt Al-Arab River in Al Basrah, Iraq, has recently recorded massive levels of TDS values (Total Dissolved Solids) in the water as a result of reduced fresh water discharge from sources, causing the river to become salinized due to salt wedge intrusion. Therefore, a block dam in the south reach is required to salt intrusion prevention. The main objective of this research is to simulate the hydraulic impact of a suggested barrage in Ras Al Besha on the Shatt Al-Arab River. The HEC-RAS (5.0.7) model was used to develop a one-dimensional unsteady model to gaining an understanding of the proposed barrage's influence on river behaviour. The daily discharges of the Tigris River provided as the upstream boundary conditions, while the hourly water levels of the Shatt Al-Arab River provided as the downstream boundary conditions. The model was initially run on the basis of daily discharges in Aug 2018 and March 2020 for the model's calibration and verification. Then, a model was run with a proposed barrage, Four cases of discharge were chosen which were the low and moderate discharge that equal to (20-50-100 and 250) m3/s with adopted spring tide cycle. The operation scenarios were examined under the influence of three cases of barrage gates (fully opened, 50% open and programmed opening). The results indicate that the investigated discharges will cause a significant problems in navigation depths, especially in the case of the programming of gates opening where the stages drop range between 2.01-3.3m comparing with the normal case. Furthermore, the velocity indicators show that the significant reduction in velocity upstream the barrage led to more sedimentation in the river reach.

scholarly journals Investigation of Salt Intrusion Condition in the Belat Estuary

2018 ◽  
Vol 150 ◽  
pp. 03005
Author(s):  
Jacqueline Isabella Gisen ◽  
Siti Syuhaida Adnan ◽  
Ahmad Amirul Ahmad Tajudin ◽  
Tian Xian Chan
Keyword(s):  
Fresh Water ◽  
Water Intake ◽  
Sea Water ◽  
Water Discharge ◽  
Spring Tide ◽  
Salinity Distribution ◽  
Salt Intrusion ◽  
Conducting Salt ◽  
High Precipitation ◽  
Fresh Water Discharge

Awareness on salt intrusion problem is still lacking in Malaysia due to high precipitation in the region. However, the El-Nino phenomenon that occurred recently has caused extremely low fresh water discharge in the Kuantan River which allowed the sea water to intrude further into its water intake region. Consequently, the Belat River may become potential water resources alternative to build new water intake station for the water supply in the Kuantan River Basin. The aims of this study are to: 1) investigate the salinity distribution in the Belat Estuary; 2) evaluate the applicability of the 1-D analytical salt intrusion solution; 3) determine the calibration parameters in the salt intrusion model. Salt intrusion measurements was conducted during the dry season at spring tide when the fresh water discharge is the minimum. Collection of data such as hydrological data, river cross section and salinity were collected to be used in the salt intrusion analysis. The results obtained show good agreement between the simulated and observed salinity distribution in the estuary with low RMSE and high NSE values. This indicates that the model is reliable and can become an important tool for water manager in conducting salt intrusion study for this area.

scholarly journals NUMERICAL MODEL FOR DENSITY CURRENTS IN ESTUARIES

1976 ◽  
Vol 1 (15) ◽  
pp. 188 ◽  
Author(s):  
Karsten Fischer
Keyword(s):  
Fresh Water ◽  
Numerical Models ◽  
Salt Water ◽  
Water Discharge ◽  
Physical Models ◽  
Stream Velocity ◽  
Density Currents ◽  
Salt Intrusion ◽  
Salt Wedge ◽  
Flow Models

In the estuarine mixing areas of salt water and fresh water the vertical stream velocity profile generally is strongly affected by the baroclinic forces, giving rise to upstream currents near the bottom. Such reverse currents occur not only in stratified estuaries, but also in estuaries of the well-mixed type |1|, and they may cause problems like strong shoaling areas, salt intrusion, or difficulties when disposing wastes or dredged material |3|. The contributions of the salinity variations to the tidal motion are comparable to the contributions from the fresh water upland discharge |1|. For well-mixed estuaries with negligible fresh water discharge, the tidal velocities and water elevations may be obtained from numerical vertically averaged models or from physical homogeneous-flow models, but for all other conditions or desired results one has to use numerical vertically discretized models or physical inhomogeneous-flow models. As numerical and physical models have different properties and deficiencies, they may be used complementarily rather than concurrently |4|, the farfield regime apparently becoming the domain of numerical models. The increased public and scientific interest in water quality problems led to the development and application of baroclinic numerical tidal models |5, 6| . The present paper is concerned with the question, how well the action of baroclinic forces can be represented by numerical techniques. As a test example, the salt wedge problems is tackled. Studies on salt wedges by means of physical models have been very sucessful |1, 7|, but mathematical approches were confined to analytical solutions for the stationary salt wedge |8 - 10| and simple geometric boundaries only. The numerical approach is free from these restrictions, giving a solution of the complete equations of motion, continuity, and convection-diffusion simultaneously.

scholarly journals Flood Hazard Analysis of Proposed Regulator on Shatt Al-Arab River

Hydrology ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 80
Author(s):  
Ahmed Naseh Ahmed Hamdan ◽  
Abdulhussain A. Abbas ◽  
Alauldeen T. Najm
Keyword(s):  
Boundary Conditions ◽  
Flood Hazard ◽  
Hazard Analysis ◽  
Flood Wave ◽  
Long Distance ◽  
Salt Intrusion ◽  
Tigris River ◽  
Open Case ◽  
Analysis System ◽  
S Peak

Recently, the Shatt Al-Arab River has suffered from increased salinization of its water due to the reduction of freshwater from its tributaries, mainly from the Tigris River, which has resulted in long-distance salinity intrusion. Therefore, there is a need to establish a regulator in the Abu-Flus district to prevent salt intrusion. The aim of the study is to investigate the effect of a proposed regulator on the Shatt Al-Arab River with simulations using the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) model. The upstream boundary conditions were the daily discharges of Tigris River and the downstream boundary conditions were the hourly water stages of the Shatt Al-Arab River. The river model was operated by using the daily discharges recorded in 2014 for calibration and verification of the model. Then, a program operated with a suggested regulator and a flood wave assumed a 200 m3/s peak flow for a duration of 27 days. The flooding occurrence period of the flood wave was investigated under the effect of three study cases of regulator gates, which were fully open (case B1), tide gate (case B2), and fully closed (case B3). The results showed that flooding inundation occurred only in two cases (B2 and B3). These results will encourage the construction of the regulator considering certain precautions.

scholarly journals Analytical approach for determining the mean water level profile in an estuary with substantial fresh water discharge

2015 ◽  
Vol 12 (8) ◽  
pp. 8381-8417 ◽  
Author(s):  
H. Cai ◽  
H. H. G. Savenije ◽  
C. Jiang ◽  
L. Zhao ◽  
Q. Yang
Keyword(s):  
Water Level ◽  
Fresh Water ◽  
Flood Control ◽  
Analytical Approach ◽  
Water Discharge ◽  
Water Levels ◽  
Wide Range ◽  
Mean Water Level ◽  
The Mean ◽  
Fresh Water Discharge

Abstract. Although modestly, the mean water level in estuaries rises in landward direction induced by a combination of the salinity gradient, the tidal asymmetry, and the backwater effect. The water level slope is increased by the fresh water discharge. However, the interactions between tide and river flow and their individual contributions to the rise of the mean water level along the estuary are not yet completely understood. In this study, we adopt an analytical approach to describe the tidal wave propagation under the influence of fresh water discharge, in which the friction term is approximated by a Chebyshev polynomials approach. The analytical model is used to quantify the contributions made by tide, river, and tide–river interaction to the water level slope along the estuary. Subsequently, the method is applied to the Yangtze estuary under a wide range of river discharge conditions and the influence of tidal amplitude and fresh water discharge on the longitudinal variation of mean water level is explored. The proposed method is particularly useful for accurately predicting water levels and the frequency of extreme high water, relevant for water management and flood control.

scholarly journals Analytical approach for determining the mean water level profile in an estuary with substantial fresh water discharge

2016 ◽  
Vol 20 (3) ◽  
pp. 1177-1195 ◽  
Author(s):  
Huayang Cai ◽  
Hubert H. G. Savenije ◽  
Chenjuan Jiang ◽  
Lili Zhao ◽  
Qingshu Yang
Keyword(s):  
Water Level ◽  
Fresh Water ◽  
River Discharge ◽  
River Flow ◽  
Water Discharge ◽  
Value Theory ◽  
Velocity Amplitude ◽  
Mean Water Level ◽  
The Mean ◽  
Fresh Water Discharge

Abstract. The mean water level in estuaries rises in the landward direction due to a combination of the density gradient, the tidal asymmetry, and the backwater effect. This phenomenon is more prominent under an increase of the fresh water discharge, which strongly intensifies both the tidal asymmetry and the backwater effect. However, the interactions between tide and river flow and their individual contributions to the rise of the mean water level along the estuary are not yet completely understood. In this study, we adopt an analytical approach to describe the tidal wave propagation under the influence of substantial fresh water discharge, where the analytical solutions are obtained by solving a set of four implicit equations for the tidal damping, the velocity amplitude, the wave celerity, and the phase lag. The analytical model is used to quantify the contributions made by tide, river, and tide–river interaction to the water level slope along the estuary, which sheds new light on the generation of backwater due to tide–river interaction. Subsequently, the method is applied to the Yangtze estuary under a wide range of river discharge conditions where the influence of both tidal amplitude and fresh water discharge on the longitudinal variation of the mean tidal water level is explored. Analytical model results show that in the tide-dominated region the mean water level is mainly controlled by the tide–river interaction, while it is primarily determined by the river flow in the river-dominated region, which is in agreement with previous studies. Interestingly, we demonstrate that the effect of the tide alone is most important in the transitional zone, where the ratio of velocity amplitude to river flow velocity approaches unity. This has to do with the fact that the contribution of tidal flow, river flow, and tide–river interaction to the residual water level slope are all proportional to the square of the velocity scale. Finally, we show that, in combination with extreme-value theory (e.g. generalized extreme-value theory), the method may be used to obtain a first-order estimation of the frequency of extreme water levels relevant for water management and flood control. By presenting these analytical relations, we provide direct insight into the interaction between tide and river flow, which will be useful for the study of other estuaries that experience substantial river discharge in a tidal region.

scholarly journals TWO-POND FEEDING NURSERY FISH BREEDING COMPLEX

2020 ◽  
Author(s):  
Vl. N. Shkura ◽  
◽  
A. V. Shevchenko ◽  
Keyword(s):  
Water Supply ◽  
Water Discharge ◽  
Water Levels ◽  
Design Solution ◽  
Fish Ponds ◽  
Pipe System ◽  
Fish Trap ◽  
Fish Breeding ◽  
The Difference ◽  
Search Design

Purpose: development and description of the layout and design solution for a two-pond feeding nursery fish-breeding complex, which characterizes by compact placement of its constituent structures and their adaptation to the topographic conditions of the territory. Materials and methods. The theoretical and empirical basis for the development was made up of well-known recommendations on design and construction of pond complexes and survey data of operating fish-breeding facilities and their structures. During the development, the technologies of search design of engineering projects in compliance with fish breeding requirements and restrictions were used. Results. The fish-breeding complex includes: two fish-breeding ponds with a common dividing dam and a water supply system including a pumping station; water supply pipe system; a system of devices and structures that ensure the release of fish grown in ponds into a fish trap; spillway devices for discharging water from ponds and a fish trap with a set of regulating elements. Fish ponds are located on the floodplain lands of the river Don and are formed by protecting dikes. The bed of the reservoirs is planned with sections with longitudinal and transverse slopes to the water-fish collecting and-transporting ditches arranged in their bottom, allowing them to be emptied and the fish grown in the ponds to be directed to the outlet structures. The release of fish from the ponds is carried out by two tower water outlets. The design of the fish trap provides for the accumulation and seine fishing, it is equipped with means for regulating water discharge and maintaining conditions for fish. Conclusions. The developed layout and design solution for a two-pond fish-breeding complex with one fish trap is adapted to the local relief and the difference in water levels in ponds and in water intake. The implemented layout and design solutions can be used in the development of similar objects

scholarly journals SPECIES COMPOSITION AND DIVERSITY OF TIDAL TRAP NET CATCHES IN THE WATERS OF INDRAGIRI HILIR, RIAU, INDONESIA

2017 ◽  
Vol 7 (1) ◽  
pp. 47
Author(s):  
Badrudin Badrudin ◽  
Bambang Sumiono ◽  
T.S Murtoyo
Keyword(s):  
Species Composition ◽  
Fresh Water ◽  
Coastal Waters ◽  
Water Discharge ◽  
Fresh Water Discharge

The coastal waters of the eastern part of lndragiri Hilir, Riau, which are mostly estuarine, are influenced by the huge fresh water discharge and are usually fertile.

scholarly journals Role of intertidal wetlands for tidal and storm tide attenuation along a confined estuary: a model study

2015 ◽  
Vol 3 (5) ◽  
pp. 3181-3224 ◽  
Author(s):  
S. Smolders ◽  
Y. Plancke ◽  
S. Ides ◽  
P. Meire ◽  
S. Temmerman
Keyword(s):  
Surface Area ◽  
Wave Attenuation ◽  
Spring Tide ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Storm Tide ◽  
Flood Risks ◽  
Model Study

Abstract. Coastal lowlands and estuaries are subjected to increasing flood risks during storm surges due to global and regional changes. Tidal wetlands are increasingly valued as effective natural buffers for storm surges by dissipating wave energy and providing flood water storage. While previous studies focused on flood wave attenuation within and behind wetlands, this study focuses on the effects of estuarine wetland properties on the attenuation of a storm tide that propagates along the length of an estuary. Wetland properties including elevation, surface area, and location within the estuary were investigated using a numerical model of the Scheldt estuary (Belgium, SW Netherlands). For a spring tide lower wetland elevations result in more attenuation of high water levels along the estuary, while for a higher storm tide higher elevations provide more attenuation compared to lower wetland elevations. For spring and storm tide a arger wetland surface area results in a better attenuation along the estuary up to a threshold wetland size for which larger wetlands do not further contribute to more attenuation. Finally a wetland of the same size and elevation, but located more upstream in the estuary, can store a larger proportion of the local flood volume and therefore has a larger attenuating effect on upstream high water levels. With this paper we aim to contribute towards a better understanding and wider implementation of ecosystem-based adaptation to increasing estuarine flood risks associated with storms.

scholarly journals Comparison of empirical models with intensively observed data for prediction salt intrusion in the Sumjin River estuary, Korea

2009 ◽  
Vol 6 (2) ◽  
pp. 1879-1905 ◽  
Author(s):  
D. C. Shaha ◽  
Y.-K. Cho
Keyword(s):  
River Discharge ◽  
Neap Tide ◽  
Spring Tide ◽  
River Estuary ◽  
High Water ◽  
Empirical Models ◽  
Length Scale ◽  
Salt Intrusion ◽  
Salinity Data ◽  
Comparative Results

Abstract. Intensive measurements of salt intrusion in the Sumjin River estuary were taken at high and low waters during both spring and neap tides in each season from August 2004 to April 2007. The estuary demonstrated partially- and well-mixed characteristics during the spring tide and stratified condition during the neap tide. The salt intrusion at high water varied from about 13.39 km in summer 2005 to 25.62 km in autumn 2006. The salt intrusion depended primarily on the freshwater discharges rather than those of spring-neap tidal oscillations. Analysis of three years of observed salinity data indicated that the salt intrusion length scale in the Sumjin River estuary was proportional to the river discharge to the −1/5 power. Five empirical models were applied to the Sumjin River estuary to explore the most suitable as an easy-to-use tool for prediction of the salt intrusion length as functions of the geometry, river discharge and tide. Comparative results showed that the Nguyen and Savenije (2006) model developed under both partially- and well-mixed estuaries yielded the most satisfactory results of all the models studied for computing the salt intrusion length in the Sumjin River estuary. Our study suggests that the model can generate reasonable results for stratified conditions also.

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