Worldwide and especially in less developed regions, process-based evaluations and/or geomorphological information on large-scale rivers are still scarce. Such investigation become of ‎urgent ‎need due to the climate change and expected occurrence of extreme floods and drought which ‎may ‎threaten the safety of nearby and downstream cities, especially in regions that are highly sensitive and ‎affected by climatic changes. The Tigris River, in Iraq, is one such river that has undergone significant alteration to its flow and morphologic aspects due to climate change and the construction of many dams. However, morphology and its change for many reaches of this river are still uninvestigated. To this end, field and satellite-based investigations into the morphology of a reach located between Makhool District and Tikrit City have been conducted. In addition to the cross-sectional survey-based determination of the reach geometrical aspects, a sinuosity indices-based evaluation of the reach planform was implemented, utilizing a satellite indices-based approach. Furthermore, the characteristics of bed material were identified through field sampling. Investigation results show that the reach has a steep bed slope and many islands of low altitude with an elongated shape. The reach has a mild sinuosity with alternating bars. The dominant particle sizes of the bed material are coarse and medium gravel with a dominant particle shape of disc particles. Moreover, the satellite-based change detection indicated the fading out and disappearance of some secondary channels, the growth of many islands, and the movement of some bends downstream. The percentage of changing parts for the period 1975–2021 is 14%. Most of this change, 11%, occurred after the construction of the Mosul Dam. This reveals the sensitivity of reach morphology to flow change due to the construction of dams. The conducted fieldwork and the applied methodology contribute to supporting efforts to add knowledge worldwide about uninvestigated rivers. Doi: 10.28991/CEJ-2022-08-07-03 Full Text: PDF

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Field and Satellite Images-Based Investigation of Rivers Morphological Aspects

To reduce the negative effects of using treated wastewater (TW) on soil properties, several techniques, methods, and strategies are used. One of these new techniques is electromagnetic (EM) water treatment technology. Using the aqua-4D physical water treatment device, we studied the effect of irrigation with electromagnetically treated TW (ETW) on soil and drainage water characteristics. Replicated pot experiments involving electromagnetically treated and non-ETW applied to cultivated and uncultivated soil were conducted under shelter. Results showed that irrigation with ETW increases soil moisture, soil electrical conductivity (ECe) and soil available K, whereas it decreases soil alkalinity (pH) and soil chemical contents such as Na+, Cl–, Ca2+, Mg2+, and SO4 compared with non-ETW, for both uncultivated and cultivated soils. It was also observed that irrigation with ETW caused a significant increase in volume, electrical conductivity (EC), and soluble salts of drainage water compared to non-ETW. In this regard, our study has shown promising potentials for EM treatment to use TW in agriculture as well as to improve soil quality.

Effect of electromagnetic treatment of treated wastewater on soil and drainage water

A pot experiment was conducted in winter season of 2015-2016 at the experimental farm, Faculty of Agriculture, Mansoura University, Dakahlia Governorate, Egypt to study the interaction effect between some kinds of organic acids (Humic acid 200 mg.L-1, Ascrobic acid, Salicylic acid and Glycine at rate of 330 mg.L-1), and irrigation water having different salinity levels (0.4, 2.12, 4.82 and 9.11 dS.m-1) on wheat (Triticum aestivum l.) Suds 12 variety grown on clayey soil. The experimental design was split plot design with two factors in three replicates .The obtained results can be summarized as follow ; the dry weight of grain (g.pot-1) was decreased with increasing water salinity levels from 0.4 dS.m-1 (tap water) till 9.11 dS.m-1 by 0.2.12; 7.73 and 12.34 compared to control (tap water, 0.4 dS.m-1). It could be arranged the organic acids for increasing straw dry weight in the following order Sa> Aa> Ga> Ha. Whereas , it could be arranged the organic acids for 100 grains weight in the following order Sa> Aa> Ga> Ha. Also, it was found that foliar application of Ga (330 mg/l) under normal conditions and all studied levels of salinity gave an increase in plant height compared to the other organic acids. The majority data of the studied nutrients content were not significantly affected by all studied factors and/or salinity levels except for Na and N content in straw and P content in grain. There was a decreasing effect in nutrients content due to increasing salinity levels except for sodium content in both straw and grain. A significant increase in Na content under the different studied salinity levels was found in both straw and grain of wheat plant, where the highest Na% in straw was 2.04% (S3A2) which was gained with ascorbic acid with salinity level=9.11 dS.m-1. Whereas, the highest mean value of Na% in grain was 0.24% (S3A3). The highest N content in straw was gained with Sa (2.38%), whereas, it reached 3.778% in grain using Aa (ascorbic acid with 330 mg/L). The highest mean value of P% in grain was 0.639% (S0A2) which was obtained with the treatment of (Aa) ascorbic acid + (tap water) salinity level of 0.4 dS.m-1 .The highest mean value of P% in straw was 0.065% (S0A2). So the highest accumulation of P was gained with the treatment of (Aa) ascorbic acid + (tap water) salinity level of 0.4 dS.m-1, but the highest accumulation of K was gained with the treatment of Ga (glycine acid treatment)+ salinity level of 9.11 dS.m-1. Finally, it is recommended to use Sa (salicylic acid ) and/ or Ga (glycine acid) with concentration of 330 ppm which may increase the ability of wheat plant to grow efficiently and successfully under the stressed saline conditions

https://jssae.journals.ekb.eg/article_35678_e6f3f234e89119c210ef8ae189504b21.pdf

Response of Wheat Plant to Foliar Application of Organic Acids under Saline Conditions

A flood happens when water floods wet land. In Iraq, there have been floods several times in the Tigris River, but the flood in 2019 was one of the major events that have greatly affected Maysan city. This paper shows the study of Maysan's extreme flood with hydraulic models. HEC-RAS two dimensional has been utilized to model the action of the study area from the downstream of Kut Barrage to Al-Musandaq escape, at the Tigris River. The model includes descriptions of simulated temporal parameters such as water depth and flow velocity. HEC-RAS Validation of simulated flood outcomes was done by correlation coefficient (r) Equation Between simulated and observed data, where the coefficient of r for calibrating the Tigris River and the Al-Musandaq escape was 0.995 and 0.991 in an appropriate range, respectively. The validation results demonstrated that the HEC-RAS model performance is highly efficient and can be implemented for design and production by hydrologists or water resources engineers.

https://iopscience.iop.org/article/10.1088/1757-899X/1090/1/012122/pdf

Development and classification of flood hazard map using 2D hydraulic model

The AlAdhaim Dam is located 133 kilometers northeast of Baghdad. It is a multipurpose dam and joints the Iraqi dam system in 2000. It has a storage capacity of 1.5 billion m3. The dam has an ogee spillway with a length of 562 m, a crest level of 131.5 m.a.m.s.l. and a maximum discharge capacity of 1150 m3/s at its maximum storage height of 143 m.a.m.s.l. This research aimed to investigate the hydrodynamics performance of the spillway and the stilling basin of AlAdhiam Dam by using numerical simulation models under gated situations. It was suggested to modify the dam capacity by increasing the dam's storage capacity by installing gates on the crest of the dam spillway. The FLUENT program was used to simulate the flow over the spillway. The free surface was calculated using the volume of fluid (VOF) method. To deal with turbulence, the SST k-ω turbulence model was used. The study showed that the spillway is capable of carrying the designed flood discharge and the modified conditions with negative pressure behind the gate and at some points along the spillway. Hydraulic jumps occur at various distances throughout the plunge pool depending on the incoming velocity in the flip bucket.

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Flow Over the Spillway of AlAdhiam Dam Under Gated Condition

This study was conducted to examine the discharge capacity of the reach of the Tigris River between Kut and Amarah Barrages of 250km in length. The examination includes simulation the current capacity of the reach by using HEC-RAS model. 247cross sections surveyed in 2012 were used in the simulation. The model was calibrated using observed discharges of 533, 800, 1025 and 3000m3/s discharged at Kut Barrage during 2013, 1995, 1995 and 1988, respectively, and its related water level at three gauge stations located along the reach. The result of calibration process indicated that the lowest Root Mean Square Error of 0.095 can be obtained when using Manning’s n coefficient of 0.026, 0.03 for the Kut- Ali Al Garbi and Ali Al Garbi- Amarah reaches respectively, and 0.03 for the flood plain of the whole reach under study. The reach under study has two lateral inflow streams, UmAljury, which joins Tigris River at station 51km, and Aljabab, which joins Tigris River at station 57km. The discharge of Aljabab varies between 0 and 400m3/s and the discharge of UmAljury varies between 0 and 50m3/s.                     The results showed that the current capacity of the main channel of the reach of the Tigris River between Kut and Amarah Barrages is 400m3/s. The water levels kept less 1m than both levees in case of discharging 1800m3/s from Kut Barrage, with no lateral inflows, and 1700m3/s with lateral inflow. The reach of Tigris River fails to accommodate the flood discharge of 3300m3/s which is the discharge of the flood of 1988 measured at Kut Barage. It can be concluded that the reach had large amount of sediment for the period from 1988 to 2012 and the reach capacity reduced to about half its capacity of 1988 during this period.                                                          The results of removing 12 islands and 2 sidebars by reshaping the current condition into trapezoidal cross-section will decrease the surface water levels by 20cm and flow of 1900m3/s can be discharged safely at Kut Barrage without any lateral inflow and 1800m3/s with lateral inflow from the tributaries. While, expand 58 narrow cross-sections that choking the flow, the water levels along the reach are lowered by an average of 20cm in addition to that 20cm when modifying the cross-sections at the islands and sidebars. In this case, flow of 2100m3/s can safely be discharged from Kut Barrage without any lateral inflow and 1900m3/s with lateral inflow. The result when modifying additional 111 cross-sections showed that the reach can safely accommodate a flood wave of 3300m3/s from Kut Barrage without any lateral inflow and 3000m3/s with lateral inflow.

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Current and Modified Flood Discharge Capacity of a Reach of Tigris River between Kut and Amarah Barrages

Magnetized water is achieved by passing water through a field of magnet. Over the few past decades, many studies and researches have reported significant evidences that some properties of water can be changed as it passes through a magnetic field. The change in the physical properties of water can improves the use of water in different arias.  It can have a promising potential of application especially in the fields of irrigation and drainage. However, the effects of magnetic field on properties of water are not yet being well developed and is still a challenging subject.In this research, magnetized water was used to leach salt affected silty loam soil. A laboratory test rig was designed and constructed for this purpose. The rig consists of a constant head reservoir, a variable intensity water magnetization device, soil columns, and drain collection tanks.  Five different magnetic intensities and five different times of exposure were used in the treatment of water used for leaching soils. Leaching water drained form the soil samples were tested for EC and pH. EC is a general indicator for all anions and cations being leached. Results were analyzed and compared to the tests results of leaching of soil by using untreated water.The results showed that the efficiency of magnetized water in removing salts from the soil is more than the untreated water. As the magnetic intensity and the time of exposure are increased, the more salts were leached out of the soil. Keywords: magnetized water, soil salinity, soil reclamation, salt affected soil, leaching of soil.

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Leaching of Salt Affected Silty Loam Soil by using Magnetized Water

The hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element. These elements were used to find the best configuration of roughness elements that can be applied to change the flow's hydraulic characteristics. ANSYS Parametric Design Language, APDL, and Computational Fluid Dynamics, CFD, was used to simulate the flow in an open channel with roughness elements. CFD can be used to study the hydrodynamics of open channels under different conditions with inclusive details rather than relying on the costly field and time-consuming. Runs were implemented with different conditions, the discharge, and water depth in upstream and downstream of the flume. T-shape roughness elements with height equal to 3cm placed in three different configurations, two lines, four lines, and fully rough configurations were tested. The results show that the effect of roughness elements increasing with increasing the number of lines of roughness elements. Cases of four lines and fully rough configurations have almost the same hydraulic performance by having the same results of the velocity decrease percentage, which is decreased by approximately about 66% and 61% of the control case's velocity in the zone near the roughness elements consequently. But the difference is that four lines configuration is affected in a part of the test section. This behavior increases the velocity values by about 11% in the other side and by about 10% near the free surface in the case of four lines configuration and increased by about 32% above the roughness elements in a fully rough configuration.

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A Computational Fluid Dynamics Investigation of using Large-Scale Geometric Roughness Elements in Open Channels

An Experimental Study on Investigating and Controlling Salt Wedge Propagation

This paper presents a numerical simulation of the flow around elliptic groynes by using CFD ‎software The flow was simulated in a flume with 4m long, 04m wide, ‎and 0175m ‎high ‎‎with a constant bed slope Moreover, the first Groyne placed at 1m from the flow ‎‎inlet with a ‎constant the Groyne height of 10cm and a 1cm thickness, and the ‎width of Groynes equals ‎7cm‎ A submergence ratio of the elliptic Groynes of 75% was assumed, corresponding to a discharge of ‎00057‎m3/sec The CFD ‎model showed a good ability to simulate the flow ‎around ‎Groynes with ‎ good accuracy The results of ‎CFD software showed that when using double elliptic Groynes, the bed shear stress is decreased with the ‎increase in the spacing between Groynes, as well as and the best spacing between the double ‎elliptic Groynes is twice of the Groyne width Moreover, the used number of Groynes has no ‎much ‎impact ‎on velocity and shear ‎stress values

/pdf/investigations-on-the-impact-of-using-elliptic-groynes-on-i1m7r77arp.pdf

Riyadh Z. Azzubaidi

Papers

Current and Modified Flood Discharge Capacity of a Reach of Tigris River between Kut and Amarah Barrages

Leaching of Salt Affected Silty Loam Soil by using Magnetized Water

A Computational Fluid Dynamics Investigation of using Large-Scale Geometric Roughness Elements in Open Channels

An Experimental Study on Investigating and Controlling Salt Wedge Propagation

Investigations on the Impact of Using Elliptic Groynes on the Flow in Open Channels