Print ISSN: 1813-0526

Online ISSN: 2220-1270

Main Subjects : Dams and Water resources Engineering

Forecasting the Reconnaissance Drought Index (RDI) Using Artificial Neural Networks (ANNs)

Rana M. A. Qassab Bashi; Abdel Wahab M. Younes Al gazzak; Omar M. A. Mahmood Agha

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 2, Pages 140-155
DOI: 10.33899/rengj.2022.132569.1149

The study of drought and its forecasting plays an important role in planning and managing water resource systems, especially in extreme climatic periods. This study aims to analyze and forecast drought characteristics, through the use of the Reconnaissance Drought Index (RDI) in order to analyze temporal and spatiotemporal climatic drought in nine climate stations in the Kurdistan Region of Iraq for the period (1973-2020) to detect the beginning and end of the drought period, as well as forecasting future droughts using two types of artificial neural networks: Recursive Multi-Step Neural Networks (RMSNN) and Direct Multi-Step Neural Network (DMSNN). The results revealed that the driest years were in the years (1998-99) for Amadiyah, Erbil and Sulaymaniyah stations, and the years (2007-08) for the rest of the stations in the study area. Moreover, the results of the two models depending on the simulation methods adopted have shown the ability of these models with regard to the forecasting for the last six years, and the ability of both models to forecast with an increase in the amount of error as we go forward. However, the (DMSNN) model was more accurate, as shown by the results of the statistical tests.

The Effect of Magnetized Water with Certain Intensities on Salts Leaching Efficiency from Agricultural Soils

Marwan Jassim Mohamed AL-Ubaide; Anmar Abdul-Aziz Altalib

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 2, Pages 166-177
DOI: 10.33899/rengj.2022.132898.1159

Two saline soils taken from two sites inside the Mosul city of (mrs1, mrs2), and two types of water, drinking water and well water, were exposed to two magnetic strengths (4000,2000) gauss, and three transparent cylinders with a diameter of 140 mm and a height of 500 mm were used. The leaching process continued until infiltration of 5 liters of water with twice repetition for each condition with stability of soil conditions (moisture, bulk density) and temperature difference in each experiment. The results showed a decrease in the electrical conductivity EC of the soil paste extract, which reached (75.7, 90.5) % for mrs2 soil, which is the most saline for Washing with an intensity of 4000 gauss for (drinking, well) water respectively. The percentage of salts in the leaching water increased, and the distribution and concentration of salts increased with the progression of water in the soil column, in addition to the decrease in the concentrations of salt ions such as sodium and sulfate by increasing Magnetization intensity and less leaching for a longer period of time, especially for well water.

Quantitative Characteristics of Groundwater and its Distribution in Tal-Afar Region- Iraq

Asaad Mahmoud Shehab ALKnoo; Abdulwahab Mohammad Younis Al gazzak

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 2, Pages 156-165
DOI: 10.33899/rengj.2022.131941.1137

The current research aims to know the quantitative characteristics of groundwater and its spatial distribution in Tal Afar district. It was relied on a set of data related to groundwater. All of them were entered into the GIS environment for the purpose of performing digital manipulations and drawing out maps. It was found that the depth of the groundwater ranges between (0-519) m, the stable groundwater level is within (0-89) m, and the variable groundwater level is (0-165) m. And the amount of decrease in the wells was within (0-146.4) m, and the productivity of these wells ranged between (37.28-0) L/sec, and the amount of conductivity was between (1345-0) m2 / day, and the productivity of water springs spread in the study area It was within (0-1000) L / sec. The study showed that the distribution and direction of the wells are from the northwest to the southeast of the study area and its standard distance covered 61.5% of the wells data, and the direction of the wells distribution was 120º towards the north in an oval shape that included approximately 66.76% of the data entered wells.

Modeling of Wetting Pattern Under a Linear Drip Source Buried in Layered Soil

Muna Abdulkareem Aljbouri; Younis Mohammed Hassan; Ahmed A. M. Al-Ogaidi

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 145-152
DOI: 10.33899/rengj.2021.130677.1119

This study aims to model the wetting patterns of the homogeneous and stratified soil profile, and to derive an equation to estimate the discharge rate during the application time. The study included conducting 8 experiments to monitor the progress of the wetting patterns over time in a homogeneous and stratified soil profile. Two types of soils were used (silty clay loam and sandy Loam). The emitter was installed at a depth of 45 cm below the soil surface, and soil profiles were prepared in two different sequences and the location of the interface between the soils was changed (at the dripper, 10 cm below the dripper, 10 cm above the dripper). The results showed that there is a good agreement between the measured and estimated advancement distances, where the determination coefficient R2 ranges between 0.826 to 0.989. Moreover, the results showed that the emitter discharge gradually decreases and continues to decline with the continuation of the operating time until it reaches an almost constant value. This reduction in emitter discharge increases by increasing the clay content, soil bulk density, emitter depth, and initial moisture content. The results also showed that the largest wetting front advance distance in the horizontal and vertical directions was in the sandy loam soil profiles, while it was the least valued in the silty clay loam profiles for the same operating time. The interface between the layers also helped in the horizontal and vertical diffusion, especially when the silty clay loam soil was placed below the dripper, which helped in the spreading of water in the horizontal and vertical direction upwards.

Experimental Study of Scour Downstream Piano Key Weir Type C with Changing Height of Weir Width of Keys and Apron Solid

Arwa Abdul-razaaq Jamal; Khalid Ysseen Tahaa; Ghania Abd Al-Majeed Hayawi

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 193-204
DOI: 10.33899/rengj.2021.130402.1101

To find out mechanism scour downstream weirs and study  effect changing  ratio width of keys  Wi/Wo , length of Apron solid and studying effect of changing the lateral length B on depth and length of the maximum scour by passing different discharge and using homogeneous  soil. A laboratory study was conducted to measure depth of scour  downstream   piano key weir type C and to show effect height weir, ratio width of keys and length of apron solid. Three heights of weir (25,30,35) cm , three ratios of width keys (1,1.25,1.5) and two distances were used  For apron solid (90,120) by passing four different discharges (15, 22, 29, 36)) l/s in experiments, where number of models used nine models, on which (72) experiments were conducted. The depth of scour  for all experiments that by reducing height weir , maintaining ratio width of the keys and discharge, scour  decreases for all experiments. The results also showed that by increasing length of apron solid by 33.33%, the scour depth will be decreased by a rate ranging between (2.17-28.75)%. and that by increasing the percentage of the width keys from ratio (1) ) to ratio (1.5) scour depth decreases by a rate ranging between (13.04-47.38%) for all experiments, decreasing height of weirs from 35 cm to 25 cm, the percentage decrease scour depth ranged (20-40.2)%. To arrive at a positional equation in terms of variables and a coefficient of determination of R2 = 0.958 .

The Effect of the Spur Dikes at the Entrance to the Curved Channel on the Morphology of the Bed

Ahmed Shareef Hayder; Mwafaq Younes Mohammed

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 153-161
DOI: 10.33899/rengj.2021.131080.1127

The meander rivers are notice condition in nature more the existing river in nature. In which the river continues process in scour and deposition sediment transport normally the scour in the outer side of a river bank and the deposition will be in the lift bank. Due to centrifugal and secondary currents for the flow. To control the movement of the sediment to overcome of the scour and deposition the spur dikes used as a one way to protect the river bank and to control of the sediment movement. In this research we locate spur dike in the straight portion of laboratory channel before entering the bend or meander to see what is the effects of this spur dike. The spur was fixed in different location in this straight portion at left, right and both side in different angle (30°, 90°,135°, 150°) with different discharge (24.096, 27.477, 31.016, 34.71) l/sec. The results shown that the spur dikes at the left side are  Reduces erosion and deposition Compared without spur dike at the section (1.9, 2.9, 3.9, 6.1)m, and the large erosion and deposition was when we put spur dikes at both side of channel with angle 90°.  

Numerical and Physical Modelling to Dissipate the Flow Energy of Spillway Using Multiple Rows of Chute Blocks

Mohamed Saad Alhmdany; Mena Ahmed Alsawaf; Zeyad Ayoob Sulaiman

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 172-180
DOI: 10.33899/rengj.2021.130576.1112

Physical and Numerical models have been used to maximize the dissipation of flow energy of a sipllway, and to guarantee the occurring of hydraulic jump in the stilling basin in shorter length, and to find the right model to simulate turbulent flow properties using the techniques of Computational Fluid Dynamics (CFD). 5 models have been tested which they had different rows of chute blocks. For each, 6 slopes of chute were examined, 1:0.8, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, with 10 cm of tail water. Physical models were emplemnted to represent a sucssecfully models that compared with the theoretical model in a slope 1:1.2 for chute. Using the RNG & K-є as a turbulent theoretical model and a non uniform distribution of the mesh led to sucssesfully simulating the stream lines, velosities and shape of hydraulic jumps and Froude numbers. Using four rows of choute blocks at the end of the chute near the edge is the best design to dissipate the energy, which was 61.9%, and for spillway slope of 1:0.8, while the percentage of energy dissipation that depending reducing the distance of the roller jump and reducing the distance of the supercritical flow was laid between (17.8, 94.8)%, respectively, when the spillway slope is 1:1.0.

The Effect of Intermittent Addition on the Wetness Pattern of Subsurface Drip Irrigation

Ahmed A. khudher; Dr. Younis Mohamed Hassan

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 205-212
DOI: 10.33899/rengj.2021.130853.1123

The current study included 12 laboratory experiments on a soil model stacked inside a container with a metal structure with two transparent faces, in order to monitor the movement of the wetness front inside the soil with time; its dimensions are 50 cm, 50 cm, and 70 cm. The polka dot is fixed in one of its corners, sandwiched between the two transparent faces, to observe the quarter of the wet bulb formed in three dimensions. Experiments were carried out on two types of soil, mixture and clay, where the dripper works with two charges 130 cm and 105 cm above the dripper level. The processing is done in two ways: continuous (cycle ratio 1) and intermittent with a ratio of 1/2 cycle and a processing time of two hours for each cycle and a ratio of 1/3 cycle with a processing time of 1 hour for each cycle. The data that were monitored during the experiment period are the rate of drip discharge with time and the limits of the wetting bulb with time as well. Auto-CAD program was used for drawing the shapes of the progression of the wetness front with time from the obtained images, and these shapes were used for finding the distance of progress in the horizontal, vertical, upward and vertical downward directions for all twelve experiments. Microsoft-Excel program was used to estimate the distance of progress in the three directions in terms of the factors affecting them and with a coefficient of determination (0.902) for horizontal progression, (0.92) for vertical upward progress and (0.88) for vertical downward progress. The results showed that the droplet discharge changes with time by an exponential function, and that the rate of discharge increases at the beginning of each cycle and then returns to its true level after a period. The study also showed that the volume of wet soil because of processing a certain volume of water decreases as the cycle rate decreases.

Effect of Catch Cans Size and Can Spacing on Calculation of Uniformity Water Distribution for Grid Sprinkler Systems

Ahmed Hazim Alkhaffaf; Haqqi Ismail Yasin

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 181-192
DOI: 10.33899/rengj.2021.130619.1116

The research included studying the effect of each of the size of catch  cans and the spacing between them on the calculation of water distribution uniformity coefficient and with different spacing between sprinklers and for several sprinklers heads, The research included conducting 10 tests, each test of a different sprinkler head, which included finding three patterns for water distribution along a ray, each representing a radius of a circle of wetness at its center, using different sizes of catch cans, where for each ray there is a different diameter of catch cans. And 480 patterns were found to distribute the field sprinkler irrigation water to cover the sizes and spacing of the catch cans and the spacing between the sprinklers and the different sprinkler heads. The research showed that when  the water distribution pattern is symmetric around the sprinkler and there is no wind; there is no effect of the diameter of the catch cans on each of the water distribution pattern along the ray, which represents the radius of the wetness circle, its center is the sprinkler, the uniformity coefficient UC and the distribution uniformity coefficient DU. And both the distribution uniformity coefficient UC and the distribution uniformity coefficient DU increases with the increase of the spacing between the catch cans. Two equations were also devised to express the uniformity coefficient UC and the distribution uniformity coefficient DU at the spacing of catch cans (1 m * 1 m) as a function of each of them at greater spacing between catch cans..

Infiltration Characteristics under Intermittent Ponding

Mohammad Tariq Mahmood altaiee; Haqqi I. Yasin; Younis M. Hassan

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 213-218
DOI: 10.33899/rengj.2022.132303.1144

The research aims to study the characteristics of each of the infiltration depth, wetting front depth and the initial moisture of the soil in the case intermittent ponding depths using successive cycles for distribution and redistribution patterns with different durations. Six laboratory experiments were conducted for cylindrical infiltration under intermittent ponding included four distribution cycles, each cycle includes distribution pattern with continuous ponding and redistribution pattern  with intermittent ponding or without ponding. Also, one cylindrical infiltration under continues ponding was done for comparison purposes.  Empirical relations were derived to express the wetting front depth, the initial moisture of soil, and the accumulative infiltration depth and infiltration rate. The results show that the average initial moisture increase during the successive distribution cycles , then seemed to be constant. The results also indicate that the infiltration depth with intermittent application is more than that of continuous application at the same application time and the difference increased as ON/OFF ratio decreased. Further, the results show that the infiltration rate with continues ponding is approximately equal to infiltration rate with intermittent ponding at the end of redistribution pattern for successive cycles.   

The Effect of the Permeable and Impermeable Spur Dikes on the Morphology of the Bed

Ahmed Shareef Hayder; Mwafaq Younes Mhammad

Al-Rafidain Engineering Journal (AREJ), 2022, Volume 27, Issue 1, Pages 162-171
DOI: 10.33899/rengj.2021.131198.1128

Flow becomes more complicated in meandering and natural channel which leads the researchers to focus on the observations of natural and laboratory channels to study the characteristics and hydraulics flow in meandering channel. Three cases for installing impermeable and permeable spur dike with 30o in the entrance of meandering channel (left side, right side and both sides of channel) are used in this study using four levels of discharge (24.096, 27.477, 31.016, 34.71) l/sec for each case. The study concluded that the permeable spur dike reduced the amount of erosion and deposition in the meandering channel and maximum deposition (18.2cm) occurred in the case of impermeable spur dike on both side of channel at 2.5m from the beginning of the curvature of meandering channel and at biggest discharge (34.71) l/sec. The results of experiments showed that the minimum erosion (9cm) occurred in the case of permeable spur dike on right side of channel at 0.3m from the beginning of the curvature of meandering channel and at biggest discharge (34.71) l/sec where the impermeable spur dike has reduced the maximum depth of engraving by (10)%.

Appropriate Operating Policy for a Reservoir System Based on Inflow States (Mosul Reservoir as a Case Study)

Ziyad Taher Ali Al-Dabbagh; Kamel Ali Almohseen

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 259-266
DOI: 10.33899/rengj.2021.130561.1111

The present study has focused on the selection of appropriate operating policies for a reservoir system to maximize the hydropower generation through the derivation of operation rule curves for different states of the inflow into the reservoir. And in order to accomplish this task, 30 years of monthly observed inflow has been used and arranged into five intervals with lower and upper values of each interval. The Genetic Algorithms techniques were implemented to obtain the optimal operating policies for each of the proposed five categories of inflow. Furthermore, and in order to alleviate the adverse effects of trapping in local maxima, a hybrid method is suggested making use of the built-in functions of optimization available in the Matlab software. The non-linear optimization function used the values of the variables obtained by GA's as initial solutions required by the optimization process to reach global solutions. One of the main objectives of the current study was to build a simple mechanism to select the most appropriate operating policy which is compatible with the nature of the inflow state entering the reservoir during a certain period of time. Consequently, a simulation model was conducted using SIMULINK technique to mimic the Mosul reservoir system which is selected as a case study to test the proposed method. The results reveal an improvement by 10 % of hydropower generation over that produced over the 30 years of real operation using the current method.

Evaluation of Aquacrop Model for Wheat Yield During Guaranteed Rain Years in Rabi'a Region

Alaa I. Naser; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 280-290
DOI: 10.33899/rengj.2021.130367.1098

AquaCrop model is an important tool for predicting and evaluating the impacts of environment and irrigation water management on crop productivity. The current study aims to evaluate AquaCrop model for wheat yield during years of guaranteed rain in Rabi'a rejoin and to study the effect of rain distribution on productivity.  with an attempt to suggest the best date for supplemental irrigation during the season to obtain the best productivity of wheat and irrigation water. AquaCrop model was calibrated with climatic and field data for Rabi'a region and start date of agricultural season was determined based on date and amount of valuable rain, with initial soil water content calculated for a root depth equivalent to 30 cm.
              The effect of rain distribution before sowing on productivity for different sowing dates (November 1, November 15, December 1, December 15, and January 1) was also studied. As well as determining the extent of need to add irrigation before sowing to improve productivity, in addition to determining the best date and depth of supplemental irrigation according to water need during wheat growth stages. . The results showed the importance of studying and observing the rain distribution before sowing and during the growing season, as delaying the sowing date can lead to an increase in productivity, as adding water with a depth of 20 mm was considered useful for improving productivity due to poor rain distribution. There was also a marked increase in productivity when adding supplementary irrigation of (60-70) mm during third or fourth stage of growth and according to the rain distribution for each year.

The Effect of Dual Water Jet on Discharge Coefficient of Vertical Spillway

Firas I. Khaleel; Ahmed Mohammed

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 291-299
DOI: 10.33899/rengj.2021.130443.1104

The water intakes is one of the important hydraulic installations that is built with the dam and is used to control the water level in the dam's lake. The vertical spillway is a type of intakes used in dams to control floods and as on intakes to change the river stream in mountainous areas. One of the most important problems that occur at vertical intakes is the vortex of water which occurs when the depth of submerge is less than the critical depth, dual water jet applied to the vertical spillway was used with different vertical and horizontal distances, the effect of dual water spillway was tested on six discharges entering the vertical spillway and the three diameters. The results shown that the dual water jet has a clear effect in dissipating the energy of the vortices formed at the vertical spillway, especially in the case of orifice flow, and it is effective in the large diameters of the vertical spillway.

Effect of Soil Surface Slope on Water Distribution Uniformity for Stationary Sprinkler Systems

Tariq Jasim Ahmed Al_farrajy; Haqqi I. Yasin

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 237-248
DOI: 10.33899/rengj.2021.130446.1105

The research included studying the effect of the slope of soil surface on water distribution uniformity of stationary sprinkler systems. 30 tests were conducted to obtain the pattern of water distribution along the radius of the wetting circle, where the sprinkler at the center, using 6 different sprinklers heads. In addition, different slopes of the surface were considered to study the wetting pattern, obtained by calculating the vertical deflection from the sprinkler head riser.  420 patterns of field water distribution were found for five slopes of the ground surface at seven different spacing, using rectangular and triangular arrangement of six sprinkler heads.
It has been concluded that both of the uniformity coefficient CU and the distribution coefficient DU decrease with the increase of the soil surface slope, (87.5% and 89% of the cases respectively). In addition, The mean percentages of maximum decrease in UC and DU due to the gradient increase from 0% to 20% for all sprinkler heads was 3.17% and 6%, respectively.and  the pattern of the water distribution does not change with the change of the soil surface slope, but rather the depth of water decreases and the range of the spraying increases as the negative slope decreases, and vice versa, the rate of water depth increases and the range of spraying decreases as the positive slope increases. Two equations were concluded to calculate the uniformity coefficient CU (or the distribution coefficient DU) for the distribution of water spray over lands with different slopes as a function of the slope and the uniformity coefficient CU (or the distribution coefficient DU) for the distribution of the water spray on flat surfaces with coefficients of determination of 0.98 and 0.977, respectively.

Infiltration and Some Physical Properties of soil

Haqqi I. Yasin; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 249-258
DOI: 10.33899/rengj.2021.129941.1089

The research aims to study the effect of some physical properties of the soil as components of sand, silt, clay, bulk density, and the initial soil moisture on cumulative infiltration depth, infiltration rate, and basic infiltration rate. Depending on data from 31 laboratory infiltration tests represented by 516 values for cumulative infiltration depth and cumulative infiltration time, including a wide range of changes in soil physical properties. Using the statistical program (SPSS) and by applying the nonlinear regression method, the best empirical equation has been derived to estimate the cumulative infiltration depth, with a determination coefficient of 0.975, as a function of some physical properties of soil and in the form of Kostakovsequation to include estimation of basic infiltration rate.

Testing the Homogeneity of Rainfall and Temperature Data in the Kurdistan Region- Iraq

Rana M. A. Qasab Bashi; Abdel Wahab M. Younes; Omar M. A. Mahmood Agha

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 227-236
DOI: 10.33899/rengj.2021.130076.1095

In this study, the homogeneity test of the rain series and the observed monthly and annual temperatures was carried out using the following test methods: Pettitt test, Buishand test (BRT), Standard Normal Homogeneity test (SNHT) and Van Neumann test (VNT) at a confidence level of 5% for 9 stations registered in Various regions of Iraqi Kurdistan for the period from 1981-2020.
The missing values ​​for the rain time series were compensated using the simple arithmetic method and the normal ratio method. The missing temperature values ​​were compensated using the simple arithmetic rate method and via the NASA Teree satellite.
The results of the homogeneity tests of the monthly rain records data showed that most of the stations were homogeneous for the winter, spring and autumn months and were not homogeneous in the summer months. As for the data of the monthly temperature records, most of the stations had inconsistent data, except for the stations of Salah al-Din and Shaqlawa. The character of homogeneity prevailed over most of the months of the year. As for the annual data of rain and temperatures, the data of all stations became homogeneous after processing the monthly data.

Efficiency, Adequacy, and Uniformity for Normal Distribution of the Application Depths

Haqqi I. Yasin; Entesar Mhamad Ghazal

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 211-217
DOI: 10.33899/rengj.2021.129134.1075

The research aims to find a set of figures in case of the normal distribution of application depths that represent relationships for the parameters used to describe the performance characteristics of the irrigation system. Using 6010 values ​​for each of the dimensionless application depth, dimensionless cumulative area, and the coefficient of variation, with the help of the SPSS statistical program, an empirical equation was obtained to estimate the dimensionless application depth as a function of the dimensionless cumulative area and the coefficient of variation. Five figures were developed containing the relationships between dimensionless net depth of irrigation, application uniformity, coefficient of variation or uniformity coefficient, application efficiency or deep percolation losses, and storage efficiency or deficit coefficient.  By knowing two of these parameters, the rest of them can be easily found from these figures.

The Effect of Entrance Edges Shape of the Diversion Channel on the Dividing Streamlines Behavior at the Junction Region

Ahmed Yahya Abdalhafedh; Nashwan K. Alomari

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 218-226
DOI: 10.33899/rengj.2021.130181.1096

                  Diversion channels are used in irrigation networks and many of water resource projects. Due to the diversion of a portion of the water, a ratio of the main flow streamlines is deflected to the diversion channel (on the diversion side). The ratio of dividing streamlines increases from the surface to the bottom due to the high momentum of the flow upper layers,which resists its diversion. This negatively affects the quality of diversion water, as the largest proportion of it comes from the high sediment concentration of the lower layers. In this study, the effect of changing the sharp edge of the diversion channel entrance to a circular edge (at upstream, downstream or both sides) on the behavior of dividing streamlines. The study considered five different percentages of the diversion discharge ratio (between 7.5% and 30% of the total discharge) with five different diameters of the circular edge. The results indicated that there is a noticeable improvement of the dividing streamlines uniformity along the flow depth when using the upstream and downstream circular edge, as well as when using large diameter of the upstream circular edge only.  In addition, increasing the discharge ratio reduces the regularity of the flow lines.

Non-Stationarity Identification in Flow Time Series Using Wavelets Transform Technique

Reyan H. Al-Mustafa; Kamel Ali Almohseen

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 2, Pages 267-279
DOI: 10.33899/rengj.2021.130600.1113

 The current study explored the possibility of using  Discrete Wavelets Transform technique (DWT) in diagnosing the  non-stationarity in hydrologic time series, which typically masks the real characteristics of those series. This helps in diagnosing the appropriate model and using it for prediction purposes.
Basically, this manuscript divided into two phases: in the first phase, a defined stochastic linear model parameter,  i.e. (ARMA (1,1)) was developed with known parameters  1 and  of (0.8 and 0.4) respectively. The ACF and PACF analyses before and after intentionally adding some defined deterministic components (such as trend, periodicity, etc.) confirm the capability of (DWT)  in diagnosing those non-stationarity sources. While phase two makes use of (DWT) technique in diagnozing the non-statioarity in an observed flow time series of al-Khabor river, Kurdistan region-Iraq,  where 24 years of flow time series is available. After removing the source of the non-stainarity diagnozed by the proposed method in the data, a stationary model (ARMA (2,1)) has been fitted. The study indicated that the proposed model was distinguished by its capabilities to work in real time, thus, the outcomes of the model is almost following the same pattern of the observed outcomes of the process under study.

Using the Submerged vanes to control the sediment entering branch channel with 30° angle with the direction of the main channel

Ehsan Elewy Salman; Mwafaq Younes Mhammad

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 90-95
DOI: 10.33899/rengj.2020.128056.1058

A common problems faced by the side intake channels are sedimentation and sediment entry. These cause problems as limiting the flow ability in irrigation channels, and threatening to waterway block when the water level is low. This laboratory study was conducted to find out the effect of using one-row immersed vans in the main channel to control the sediments amount of entering the intake channel at an angle  with two sand concentrations at granular diameter rate (  = 0.5mm). The first concentration flow rate was (1.8 ) And the second (2.22 ). The results showed that the use of a single row of submerged vans reduces the sediment amount that entered the intake channel by (35-65)% of the total sediments that were fed by the feeder channel for both concentrations. This indicates that use of submerged vans has a positive role in entry process and sediment transfer to branched channels.

Empirical Equations for Estimation of Water Distribution Uniformity Coefficient in Case of the Alternate Setting of Sprinkler Laterals

Haqqi Yasin; Zeyad Ayoob Sulaiman; Ahmed Ali Al-Ogaidi

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 128-139
DOI: 10.33899/rengj.2021.128679.1067

Among the operating and management practices that can increase the uniformity of water distribution in the portable sprinkler irrigation systems is the alternate setting of sprinkler laterals. Shifting the laterals by half the distance between laterals results in a single alternate set and shifting the laterals by half the distance between the sprinklers results in double alternate set. Data representing 66 patterns of water distribution for a single sprinkler of different types of sprinkler heads were used. By choosing many suitable sprinklers spacing and using Microsoft Excel to implement the field distribution that free of dry spots, the following coefficients were computed: uniformity coefficient, uniformity coefficient of single and double alternate set, distribution uniformity, distribution uniformity of single and double alternate set and coefficients related to sprinklers spacing. Then, using the nonlinear regression analysis provided in SPSS, empirical relationships were derived to estimate both the single and double uniformity coefficients and the single and double distribution uniformity with determination coefficients of 0.783, 0.810, 0.720, and 0.766, respectively. The spacing coefficients that lead to the maximum values ​​of the different uniformity coefficients were determined based on inferred equations. In addition, the functions proposed in previous studies used in estimating the single and double uniformity coefficients with determination coefficients of 0.608 and 0.539, respectively as well as the single and double distribution uniformity coefficients with determination coefficients of 0.584 and 0.491, respectively showed low accuracy as compared with the ones proposed in the current study.

The Use of Artificial Neural Networks In The Analysis of Seepage and Slope Stability for The Proposed Qaim Dam on The Khosar River

Farah Khazaal Saeed; Kamel Ali Almohseen; Abdulwahab Mohammad Younis

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 96-104
DOI: 10.33899/rengj.2020.128204.1062

In this study, two Artificial Neural Networks (ANN) were built to predict the amount of seepage and the factor of safety for the upstream and downstream slopes of the Qaim Dam, which was proposed to be constructed on the Khosar River.  Two cases have been taken into consideration to analyze the operation of the dam, making use of previous study used Geo-Studio 2012 program studying the stability and the seepage through dam body and its foundation. Thus, two neural networks have been proposed, the first one was for the steady-state case of the reservoir water level and the second was for the rapid drawdown of the reservoir water level. The first ANN gave a coefficient of determination for the seepage process of (0.996),while these coefficients for upstream and downstream slopes were (0.957), and (0.925) respectively. The second ANN deals with calculation of the factor of safety for the upstream slope in a rapid drawdown case, which was (0.976). Sensitivity analyses were also conducted to figure out the most effective variables. It is shown that the most effective factor was the angle of internal friction for the soil.

Temporal and Spatial Analysis of Drought Using the Standard Precipitation Index for the Northwestern Region of Iraq

Samah Mohammed Kasim; Abdulwahab Mohammed Youns; omar Muqdad Mahmood-Agha

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 115-127
DOI: 10.33899/rengj.2020.128386.1066

The purpose of the study is to meteorological drought analysis using a standard precipitation index (SPI) in (9) climatic stations spread over the northwestern part of Iraq for the period from 1981 to 2018. Analysis was done at different time intervals and different SPI thresholds. The study showed that the percentage for wet and dry years is 48.54% and 51.46%, respectively, when rated SPI-12 = 0, and this percentage improves for short periods of time to reach 59.94% and 40.06 for wet and dry years respectively when rated SPI-6 (7-12) ) = 0. It was found that the classification of moderate humidity and moderate dryness is prevalent during that period and at all classifications and time periods, while the classification of severe dryness and extreme drought appears clearly and clearly in short time periods, especially in the stations of group (A) and (B).

Hydraulic Properties Downstream Multi-Opened Sluice Gate

mohammad yasin Al-Qattan; Ahmed Y Mohammed

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 63-68
DOI: 10.33899/rengj.2020.127108.1037

In this paper four gate openings and fifteen operating scenarios in terms of the difference in the arrangement of working gates were studied. The Expansion Ratio (e) which is (the ratio of total width of the channel to the total width of the working gates) was calculated for each scenario. It can be seen that when the value of (e) was the largest possible, which is (5.34), the value of the discharge coefficient (Cd) was also as high as possible, reached to (0.845). Also, the value of the contraction coefficient (Cc) was the highest value, (0.693). The increasing in the value of (e) means that the number of openings that work is less. Both (Cd) and (Cc) are decreases when Froude Number increased for all scenarios of gate worked operations.

Life Losses Estimation Due to Hypothetical Momentary Mosul Dam Failure & Prepare Emergency Flood Action Plan for Mosul City

Mustafa Salim Mustafa; Thair Mahmood Al-Taiee

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 78-89
DOI: 10.33899/rengj.2020.127901.1053

The life loss resulting from the momentary hypothetical failure of Mosul Dam for the area between Mosul Dam extending to the south of Mosul City was estimated depending on inundation maps resulting from flood wave simulation using IBER hydrodynamic model for storage elevation scenarios (300, 310, 320, 330 and 335) meters above sea level. The estimated number residents exposed to the flooding risk at minimum and maximum Mosul Lake storage elevation scenarios for the left and right sides of Mosul City were (257886-749625) person and for the residential communities between Mosul Dam and Mosul City were (10685-47925) person respectively. Saqib Ehsan (2009) approach was used to estimate the life losses for the study area. The human losses were estimated when there was no available warning time for minimum and maximum lake storage levels to be (17452 & 372958) persons respectively. The distances between safe places from the river center were calculated to be (3.09) km for the right side and (5.27) km for the left side of Mosul City at the lake storage elevation of 335 meter above sea level, so the average flood rise velocity and flood survival time till flood were recession completely was calculated for all the lake storage scenarios. An emergency notification action plan has been proposed for the Mosul Dam failure scenario with the most important recommendations and procedures to be under consideration during the flood disaster.

The Effect of Intermittent Constant Water Application on Soil Infiltration

Shamsaldeen Mohamed khroofa; Dr. Younis Mohammed Hassan

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 69-77
DOI: 10.33899/rengj.2020.127633.1050

In this research ,20 laboratory experiments was carried out on a column of soil with dimensions (30 cm *30 cm *45 cm) on two types of soil loamy sand and loamy ,in order to study the infiltration characteristics of the soil under sprinkling application with constant application rate under continuous and intermittent application at three constant application rates (31,52.4 and68)mm/hr ,with four cycle ratios(cr=1,1/2,1/3,1/4) for loamy sand soil and application rate (31,52.4)mm/hr and  three cycle ratios(cr=1,1/2,1/3) for loamy soil for each application rate , the study focused on two basic factor : the time to ponding ( )and the infiltration characteristics after ponding time .the study showed that using intermittent application method improves infiltration characteristics as it leads to increase in time to ponding ,this increased ranged between (3.22% to 155%)for loamy sand soil and (13.77% to 239.67%) for loamy soil at circle ratio equal  as compared with continuous application in addition to increasing the accumulative infiltration rate depth at any time for example at 180min actual application time the accumulated infiltration depth increased by (3.26% to 47%)for loamy sand soil and (10.24% to 26.94%) for loamy soil using intermittent application (cr =   ) as compared with continuous application.

Improving the Cultivated Area for Ramadi Irrigation Project Using Water Evaluation and Planning Model (WEAP)

Abu Baker A. Najm; Isam Mohammed Abdulhameed Al-bayati; Sadeq O. Sulaiman

Al-Rafidain Engineering Journal (AREJ), 2021, Volume 26, Issue 1, Pages 105-114
DOI: 10.33899/rengj.2020.128248.1063

In this study, a water evaluation and planning WEAP model was utilized to improve the Ramadi irrigation project with 28342 hectares and 326 million  annual budget for the period (2018-2019). The results showed that the total water used was 111.5 million /year representing 34.2% of Ramadi irrigation budget. The annual production was 39.3 million Kg/year for Ramadi irrigation, and the total economic returns was 16.04 million $/year. The study proposes two scenarios to improve the cultivated area. The first scenario increases water volume of the current year from 111.5 million /year to 272.12 million /year, which caused an increase in annual productivity from 39.3 million Kg/year to 144.57 million Kg/year, and economic return rose from 16.04 million $/year to 65.25 million $/year. The second scenario recorded an increase in the annual production for the current year from 39.3 million Kg/year to 192.27 million Kg/year and economic return from 16.04 million $/year to 86.79 million $/year when using additional pumps for project 2, 3 and project 5. Also, the convey loss increased from 16.72 million /year for the current year to 48.47 million /year when applying the second scenario, which equals 15% from the water budget of Ramadi irrigation.

Studying The Effect of Intake Channel Angle on the Sediment Transport Branching Channels

Ehsan Elewy Salman; Mwafaq Younis Mohammed

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 60-65
DOI: 10.33899/rengj.2020.126731.1018

An experimental investigation was conducted to observe the connection angle effect of the branched channel front with the main channel on the entering sediments amounts into the branched channel. Three angles were taken to the branched channel inlet (60°,45°,30°), that connected with the main channel from the left side with two concentrations of sand at a granular diameter rate (D50=0.5mm). The concentration flow rates were 1.8 and 2.22(g/s), respectively. The sand was fed and organized by a speed regulator to main channel to obtain the concentrations. The results showed that the 60° was better than the rest in the sediment numbers. Compared to the 30° and 45° angles, the reduction at the 60° was at (32-40)% of 40% of the discharge rate. Besides, at the 30% discharge rate, the reduction was (16-19)%. Within the study limits, it has indicated that the greater angle is the better and it reduces sediments.

Slope Stability Study of Al-Qaim Dam that Proposed to be Constructed on Khosar River – Case Study

Farah K. Saeed; Kamel A. Almohseen; Abdulwahab M. Yunis

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 75-83
DOI: 10.33899/rengj.2020.127023.1034

It is extremely significant during the design stage of an earth dam is to analyze the seepage and slope stability. The proposed Al-Qaim dam on  Al Khoser river was used as a case study to apply Geo-Studio 2012 program and its appendices Seep/w and Slope/w. Some minor modifications to the original design suggested by SOGREAH company have been proposed. The Geo-Studio 2012 program was used to analyze three states of Al-Qaim reservoir i.e. (end of construction، steady-state، and rapid drawdown). Seep/w and Slope/w have used to analyze the seepage and the stability of the slopes، the results reveal a good agreement between this analysis and the design company's results. Moreover، the present analysis achieves the requirement of safety with less volume of embankment which reduces the cost of construction substantially.

Analysis of Rainfall Data for a Number of Stations in Northern Iraq

Ihsan F. Hasan; Younis N. Saeed

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 105-117
DOI: 10.33899/rengj.2020.127531.1044

This study aimed to analyze the rainfall time series data for 9 stations in the north of Iraq, namely (Sulaymaniyah, Darbandikhan, Dokan, Duhok, Erbil, Kirkuk, Mosul, Sinjar, Tal-Afar) from 1979 until 2014 using the Multiplicative model of time series, this is for the purpose of identifying the reality of the time series variables (general trend, seasonal, periodic, random) which affected by the rains, and the prediction of monthly rainfall data for the  selected stations. The rainfall characteristics of the northern region of Iraq were also studied in terms of daily, monthly and annual distribution of rainfall rates and a relationship between intensity-Duration-Frequency (IDF) at different return periods (2, 5, 10, 15, 25, 50, 100) years has been found to identify the reality of rainstorms and provide solutions  to a number of design problems related to management and treatment of water for Basins in general and ungauged Basins in particular such as surface runoff discharge and erosion control.

Surrogate Worth Trade - Off (SWT) Method and the Decision-Making Process in Water Resources Planning and Management

Mohammed Awni Khattab; Kamel Ali Almohseen

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 118-126
DOI: 10.33899/rengj.2020.127592.1049

Multi-objective decision-making methodologies are one among widely researched areas in recent years. As a result, many technologies have been developed. Among these, is Surrogate Worth Trade - Off (SWT). SWT has emerged in the areas of water resource planning and management, and is one of the multi-objective analysis methods described as an interactive method. This study includes reviewing and applying (SWT) method to optimally operate the Mosul Dam Reservoir. This operation policy sought to achieve two contradictory objectives: diverting water from the reservoir for irrigation purposes and releasing water from it for the purpose of hydropower generation. A comparison was also made of the results that were nominated from the application of this method, namely (allocating million cubic meters/ year for irrigation and generating 1572 GW-hour/year for power generation) with the results of the research [3] which four methods for solutions have been implemented. These are: weights, constraints, goal attainment, and step method. The results reveal that the used methods gave the optimal solution by (allocating 5906 million cubic meters/ year for irrigation and generating 1,600 GW-hour/year for power generation), (6236 ,1555) , (6188 ,1558) and (6121 , 1568) respectively. from the comparison It can be concluded that (SWT)  is an efficient and promising method in identifying an operating policy for a single reservoir system with competing objectives.

Modelling of Wetting Front Advance and Discharge Change of Subsurface Line Source

Abdulghani Kh. Mohammed; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 84-92
DOI: 10.33899/rengj.2020.127221.1042

Sub-drip irrigation is one of the most important and the latest high-performance irrigation systems that are characterized by a high ability to reduce losses of deep percolation and evaporation from the soil surface. Twelve laboratory experiments were carried out to study the effect of soil texture, dripper depth and initial water content on the wetting pattern, dripper discharge. Further, non-linear regression approach was applied to predict empirical relationships for estimation the wetting pattern dimensions and actual dripper discharge. The results showed a significant match between the observed and estimated values ​​of the wetting front advance and the dripper discharge change. At a specific volume of water application, the size of wetting soil increased (8-20%) with the initial water content increase and (2.5-6.25%) with dripper depth increase and this size decreased (4.5-36%) with the clay content increase. The rate of vertical upward advance decreased with increasing the initial water content. The dripper discharge gradually decreased with the continuation of water application due to positive pressure increase at the dripper opening, and this decrease increased with increasing dripper depth, clay content and the initial water content of the soil.

Study of Scour Around Cylindrical Bridge Piers with Circular Openings

Mays Ibrahim Alsaidi; Ghania Abd Al-Majeed Hayawi; Mena Ahmed Alsawaf

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 66-74
DOI: 10.33899/rengj.2020.126863.1029

            To reduce the local scour around bridge piers and ensure their safety, an experimental study was conducted to examine the effect of a single tubular hole that faces the flow direction through three successive cylindrical bridge piers. In order to reduce the local scour, occurred because of the collision of the flux. Two groups of successive piers were used, both had diameters of 5, 11, 16 cm. First group of piers with internal tubular opening which had 20% diameter of the pier and located at half the water depth. The second group just solid pier for comparison. The spacing between them was varied to be 30, 40 or 50 cm for each group. As well as the discharge was varied. The used moveable bed material classified as non-uniform coarse sand, which had 0.5 mm mean diameter. The results showed that the presence of the openings helps effectively to reduce the depth of scour and its effect increases as the diameter of the opening increases, as the highest reduction reaches 55.56%, 53.33% and 10% for diameters 16, 11 and 5 cm, respectively. The scour depth increases when the diameter of the pier the increase of and the short distance between the successive piers.

Effect of Nozzle Angel & Cyclic Pressure Head Variation on Water Distribution Uniformity for Stationary Sprinkler Systems

Esraa Ali Younis; Haqqi Ismail Yasin

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 93-104
DOI: 10.33899/rengj.2020.127209.1040

The present  research included studying the effect of the sprinkler nozzle angle and cyclic variation of the operating pressure head on the uniformity of water distribution for many sprinkler heads spacing with rectangular  and triangular sprinkler heads arrangement for different sprinkler heads. The research conducted 40 tests to measure a single sprinkler water distribution pattern under similar climatic operating conditions by adopting the water distribution pattern along a beam that represents the radius of the wetting circle which its center is a sprinkler head for different sprinkler nozzle angles (Ɵ + 5 °, Ɵ + 3.5 °, Ɵ, Ɵ -3.5 °, Ɵ -5 °) and the constant-cyclic operating pressure head conditions for different sprinkler heads. 320 patterns were found for field water distribution pattern and uniformity coefficient for four different spacing  with  a rectangular and triangular sprinkler heads arrangement for   the sprinkler heads and  the measured water distribution patterns.
The research revealed that 70% of the uniformity coefficients in the rectangular arrangement are greater or equal to its value in a triangular arrangement. The increase in the nozzle angle results in increasing the uniformity coefficient of 1.4% for each degree, an increase in the nozzle angle, and can reach 2.4% for each degree for a specific spacing, arrangement, and sprinkler head. Also, the difference between the two water distribution patterns in the case of operating with constant pressure head  and variable pressure head is slight, but it shows in the values of the uniformity coefficient, where the maximum difference reaches 10%, and in general, the best in the values of the uniformity coefficient requires determining the nozzle angle, the spacing and the arrangement of sprinkler head as well as the case of operating pressure head constant or variable.

Testing of the Homogeneity of Precipitation Time Series in Selected Regions of Iraq

Samah Mohammed Qasim; Abdulwahab Mohammad Youns; Omar M. Mahmood-Agha

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 1, Pages 126-137
DOI: 10.33899/rengj.2020.127033.1035

Precipitation data are subject to many tests and assessments before being used for studies in the field of water resources, hydrological processes, and climate change research to ensure their reliability and quality. Homogeneity tests are considered as a useful tool to control the reliability and quality of data. In this study, a homogeneity test was performed for the monthly rainfall data distributed over different regions of Iraq. Homogeneity was examined using four tests: Pettit, SNHT, BRT and VNRT at a confidence level of 5%.The results showed that the time series for the winter months of the Ramadi, Baghdad, Hilla, Khanaqin and Karbala stations were heterogeneous, while the time series of the Al-Nakhaib, Wetba, Baghdad and Tal Afar stations during the spring months were statistically heterogeneous according to the SNHT test. While the Pettitt test showed heterogeneous results for the stations of Nasiriyah, Basra, Khanaqin and Kirkuk for the winter months. Al-Rutba, Khanaqin, Tal Afar,Sinjar,Mosul and Karbala for the spring months. The data for all stations were homogeneous, using the BRT test for the winter and spring months. VNRT test showed the heterogeneity of the data for the Samawah stations for the months of winter, Ramadi, Nakhab, Tal- Afar and Najaf for the months of spring. The current study also showed that the precipitation of all stations are classified as useful, with the exception of the Al-Nukhaib and Najaf stations, which have been classified as doubtful .

Water Management under Deficit Irrigation

Haqqi Ismail Yasin; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 1, Pages 32-40
DOI: 10.33899/rengj.2020.126551.1011

Depending on the production function, irrigation water cost function and the sale price of yield, previously, lengthy mathematical expressions have been developed to estimate the optimal levels of water used in deficit irrigation, that would maximize yield (Wm), under water limiting (Ww), and under land limiting (Wl) and the amount of water that leads to income equal to income of Wm when land is limited (Wel), and that leads to farm income equal to farm income of Wm when water is limited Wew . Therefore, in this paper, firstly the previous lengthy expressions for (Wel) and (Wew) were simplified. Secondly, simple expressions for both (Wel) and (Wew) were derived under presence of rainfall. Thirdly, very simple mathematical relations between (Wm & Wl) and (Wm & Ww) were derived in order to determine much easier expressions than those previously derived for Wel, and Wew respectively, with and without rainfall.

Planning and Decision Making Under Uncertainty (Mosul Reservoir Optimal Operating Policy- Case Study)

Mohammed Awni Khattab; Kamel A. Al-Mohseen

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 1, Pages 85-96
DOI: 10.33899/rengj.2020.126885.1032

This study is concerning the planning and decision making process of water resources projects under uncertainty. It includes a mathematical analysis to optimize the operation of the Mosul reservoir sought to achieve two conflicting goals, diverting water from for irrigation and releasing water for hydroelectric generation. Four methods of solutions have been implemented. These are: weights, constraints, goal attainment, and step method. The results reveal that the used methods gave the optimal solution by allocating 5906 million cubic meters/ year for irrigation and 1600 Gw-hour/year for power generation ),(6236, 1555), (6188, 1558),and (6121,1568) under the given inflow conditions . The current study suggested that the average value of these solutions i.e (6113, 1570) can be taken as a compromise solution to the problem. It is believed that this solution has a good chance to be selected by the decision-maker, because it contains the least possible degree of subjectivity.

Effect of Irrigation Scheduling Using CROPWAT on Water Use Efficiency and Grain Yield and Components for Maize (Zea mays L.) in Semi Arid Regions

Ahmed Azhor Thanoon

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 130-137
DOI: 10.33899/rengj.2019.164329

Irrigation scheduling is determining the appropriate time and quantity of irrigation to reach maximum production. In this research the irrigation scheduling was determined using a computer program CROPWAT , developed by FAO . The program used the climate , crop , and soil data for calculation the irrigation scheduling .The climate data represents average years (1971-2007) of pan evaporation to Mosul city for calculating the reference evapotranspiration , maize crop and light soil data , were used to input data . The program was used cases include three different irrigation timing levels are 100%, 70% and 50% of the readily soil moisture depletion(critical depletion and belowcritical depletion) with refill soil moisture content to field capacity . The results of  irrigation scheduling from the program were applied to the field experiment in the Mosul Technical Institute during the summer of 2010. The grain yield and components were measured at harvest to improve the best irrigation scheduling for maize crop in semi arid regions .
The results showed that the depth of irrigation added to three different irrigation levels 100% and 70% and 50% of the readily soil moisture depletion reached 860 and 881 and 900 mmrespectively, the number of irrigations 15, 21, 29 . The results also showed that the best irrigation scheduling for higher water use efficiency was0.55 kg/m3 and highest production356g/m2 for the treatment of 70% of  the readily soil moisture depletion. Therefore the CROPWAT is aneffective tool for planning and management of irrigation maize in semi arid regions .


Ahmad Thamer Ibrahim; Haqqi Ismail Yasin

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 25-38
DOI: 10.33899/rengj.2019.164333

The proper size and diameter of the lateral sprinkler pipe is associated with the variations of pressure head along the pipeline; the greatest pressure head variations, the smallest pipe size and thereby an increase in the required pressure head at the inlet of lateral pipe and the pumping power unit.  The pattern of water distribution of sprinklers operating with different operating pressure will accordingly varies and may leads to variations in uniformity of water application along the lateral pipe. The research purpose is to study the effect of pressure head variation on the uniformity of the water distribution along the lateral pipe by adopting different values of the friction head losses that expressed as a fraction of average operating head, and linking with spacing between sprinkler heads. Furthermore, this study aims to compare between the increase in pumping power cost to ensure operating head at the lateral inlet associated with increase in the fraction of friction head losses, and decrease in the cost of the pipe. 18 tests were carried out to obtain the water distribution pattern for single sprinkler under different pressure heads and for five different type sprinklers,the water distribution pattern of a single sprinkler was estimated as a function of distance from the sprinkler and the pressure head with non-physical formulas and high determination coefficients. Fractions of head losses due to friction were chosen to be (10, 20, 30, 40, and 50) % of the sprinkler operating head. A computer program was developed to compute the pressure head at each sprinkle, water distribution pattern, and water application uniformity of the sprinkler network system using different sprinkler head spacing and three levels of operating heads. Also, the economics of pipe size and pumping operation cost using the selected fractions of the friction head losses was studied.
The results show that the water distribution uniformity increases when the pressure head at sprinkler head increases and this increase varies according to the sprinkler type and spacing; there is no observable change between the system water distribution uniformity and uniformity coefficient of application at the average operating pressure head for all sprinkler spacings and friction head looses fractions except the case of friction head loose equal to 50% of the operating head that showed very small differences. Also, the annual pumping cost to ensure required pressure head at lateral pipe inlet using same average operation head is constant for all used sprinkles. The total annual cost increases when the adopted friction head loose in the design of lateral sprinkler pipe increases stating that the economic pipe size is associated with low friction.

Investigation of Local Scour Around Group Bridge Pier with Different Shapes

Tahseen A. GELMIRAN; Khalil I. Othman; Mustafa GUNAL

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 10-22
DOI: 10.33899/rengj.2019.164355

In this study, the establish on laboratory experiments for computing the depth of local scour (ds) around group bridge pier. For this purpose, fifteen models of bridge piers were constructed and tested, divided into five groups, of each group containing three bridge piers with the same specifications. The diameter of upstream bridge piers (D1) was varied to 2, 4, 6, 8, and 10 cm, and diameter of downstream bridge piers (D2) 10 cm for all. The spacing (S) between the bridge piers was varied three times 20, 30, and 50 cm for all groups. Considering the effectiveness study of upstream flow conditions, the size of diameters of bridge piers, the spacing between bridge piers and medium size of bed material on the maximum scour depth and scour pattern around bridge piers. The study was conductedby employing a physical hydraulic model for bridge piers operated below subcritical flow, clear-water condition and exploitation uniform cohesionless sand as bed material. The experimental results showed the scour depth (ds) increasing whenever increasing the upstream diameter (D1) of bridge pier and decreasing whenever decreasing the spacing (S) between bridge piers. The dimensional analysis techniques and statistical program were used for locating a new empirical formula with the facilitate of the experimental information; this formula is for calculating the maximum scour depth at bridge piers.

Wetting Pattern for A Two-Line Trickle Source

Qamar Moayad Bakir; Haqqi Yasin

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 1, Pages 56-65
DOI: 10.33899/rengj.2019.163116

The laboratory tests carried out 12 tests to follow the advance of wetting front at appropriate times during the wetting and redistribution phases as a resulting of water application from a single linear trickle source or two linear trickle sources with a certain spacing to soil profile. These data are used to express with an estimating relationships for the wetting pattern produced by single linear trickle source and two linear trickle sources during wetting and redistribution phases. The study showed that there is a significant correspond between the wetting pattern of the measured and the estimated by the experimental equations. The wetting pattern increases with the decreasing of spacing between the two linear trickle sources, and this increase is regular along the wetting front or the surrounding of the wetting pattern, and this increase in the vertical direction of the wetting pattern is more in sandy loam soil than in silty clay soil and vice versa in the horizontal direction, when compare among the wetting patterns at the end of the wetting phase and the redistribution phase at a total time of 72 hours.

Similarity Between Inside and Outside in Architecture A Comparative Study Between Mies Van der Roh& Robert Venturi Trends

Shaimaa AL-Dabbagh; Dr. Asma AL-Dabbagh

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 1, Pages 46-55
DOI: 10.33899/rengj.2019.163115

The relationship between inside and outside is considered as the principal one in architecture as it is one of its most important relationships in architecture’s history. Human had tended, from the very creation of being, to withhold a part of the outside space in order to form a special inside space of the building.
This is done through containment as in making the cave as a refuge or through designation as in setting a space by using vertical or horizontal elements. This process is called “inside and outside” which might be the leading generated term of building construction. Human firstly and the architect secondly aim at finding, unceasingly, a relationship between interior and exterior spaces. And, as they do so; they manipulate the outer mass, inner space and mutual boundaries in-between through shaping them in a way yielding a relationship between both interior and exterior spaces; thus, to find similarity or dissimilarity between the shapes of the outer mass and the inner mass of the interior space. The present study attempts to study the similarity characteristic by studying its contrast as a characteristic of the relationship between interior and exterior to determine the differences between the architects' trends (Mies and Venturi) regarding to the relation of inside and outside. this relationship will be having a big role in determining the patterns of buildings, their trends, and intellectual and spatial affiliations.
In order to achieve the objectives of the research, in the practical side, three (3) single residential houses were chosen for each architect, and After applying difference variables to the selected sample, throughout the study  a vision had been put into words expressed in that: the difference between inside and outside is what is known as the (In between), Which is the resultant of, basically, pro forma purposes, which are adapted to perform particular functions later as in Mies Architecture, or any strict functional purposes as in Venturi Architecture.

Improvement Water Productivity for Wheat Crop at Mosul Area

Rand Saadi Huseen; Dr. Younis Mohamed Hassan; Dr.Eman H. Sheet

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 1, Pages 24-30
DOI: 10.33899/rengj.2019.163112

This study aimed to optimize the yield of wheat crop under rainfed Agriculture at Mosul zone in Iraq . this can be reached by the selection of proper time of seeding time which gives the best crop yield for rainfed Agriculture or by adding one supplementary irrigation of selected depth and time which gives the maximum yield or best economical return.
In this study we generated data base using program (Aquacrop) for wheat yield with rainfall depth during the season for rainfall agriculture with rainfall depth +supplementary irrigation by using one irrigation during the season with depth (25,50,100)mm adding to one week of the season which is 23 week with initial water content between field capacity and wilting point with three date to begin the agriculture season the results showed that the optimal seeding time for the rainfed Agriculture is 15 December which gives 257.5 kg/ha yield and the next is 15 November 250.5 kg/ha and 15 January 89 kg/ha, For supplementary Agriculture the best time of the irrigation is the first week of the season with a depth change inversely with rain depth and the best seeding time is 15 November.

Effect of Roughened Flood Plain of Symmetrical Compound Channel on The Resistance of Flow

Aws Younes Hamed; Mwafaq Younes Mhammad

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 1, Pages 31-38
DOI: 10.33899/rengj.2019.163113

This research deals with the experimental study of the effect of roughened the flood plain of symmetrical compound channel (having 18 cm main channel and 29 cm flood plain width from both sides) on the resistance of flow using different size of gravel roughness (D50=6.8 ,16.8, 24,47) mm, as well as the flood plain is smooth.
 Five discharges (34,27.8,19.35,12,7.87)L/sec were carried out for each case, The compound channel was divided to 3 sections  perpendicular to the direction of flow  and each of them divided to 7 sections , 4 in flood plain and 3 in main channel . Pitot static tube used for velocity measurements and point gage for water surfacelevel measurement as well as the temperature of water was measurement, From the measurements it can be concluded that  the velocity over the flood plain was reduced clearly up to 40 – 70 % when the flood plain roughened by course roughness compare with that of smooth one  , while the velocity in the main channel increased to satisfy the continuity equation . Empirical equations were developed to combine the resistance coefficient n with other variables include the flow and geometry characteristics

Deriving Equation to Estimate Movement of Water in Soil for Subsurface Drip Irrigation

Dheyaa Mohamed Taha; Dr. Younis Mohamed Hassan

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 1, Pages 39-45
DOI: 10.33899/rengj.2019.163114

Subsurface drip irrigation is an efficient irrigation method because it applies water directly to the crop root zone, but one of the disadvantages of this method is the positive pressure which is formed in the soil at dripopening especially in fine soils where the drip discharge is larger than the soil infiltration capacity which leads to decrease the discharge rate because the positive pressure will reduce the operation pressure of the drip. In this study, water was applied to ahole surface which filled with gravel to a needed depth,than distributed from the holebottom to all direction through the soil. Wetting front  was observed during water supply and redistribution periods .
Eighteen laboratory experiments for watching advance of wetting front at different times, by using cuboid-shaped container, dimensions (50*50*70) cm. two side of this container are plastic sheets, soil was compacted in the container to achieve bulk density. Two soils were used in the experiments, sandy loam with initial water content (3% and 6%), discharge (0.5, 1.04 and 2.14) L/hr, and silty clay with initial water content (5% and 8.5%), discharge (0.54 and 1.08) L/hr. For the both soils (5 and 10)cm radius of gravel container  with 20cm depth was used, the container have holes from bottom and side at 5cm high to water exit. The volume of water applied was 4.5 L.
The study presents equation to estimate fully shape of wetting pattern,by using dimensional analysis techniques, the effective variables on wetting front movement had been transfered to dimensionless groups, and by using the (SPSS)software  a relationship was found between distance from center of hole to wetting front and time for all direction.

Experimental Study of the Scour Depth at Downstream Weirs Has Different Holes

Mariam Khder Mohammad Alhealy; Ghania Abd Al Majeed Hayawi

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 1, Pages 18-23
DOI: 10.33899/rengj.2019.163111

An experimental study was carried out  to deal with using a weir with circular holes to control the scour occurs behind it. The holes are located near the bed of the channel, their geometric details had been changed in its size, number and their distance from the bed of the channel. The channel bed was lined by crushed gravel with average diameter 11.1 cm. The thickness of the crushed gravel layer was 22 cm and its length was 4 m. There is 18 cases were conducted. Which the diameter of the holes were 1.6, 2.3, 3 cm, and for each size of them, the distance of the holes was 0, 0.25 or 0.5 cm, their number was one or three. These cases were compared with the case of using weir with no hole. The main hydraulic variable was the discharge, which five different discharges were  flowed for each case. The total number of the experiments was 95. The dimensions of the scour hole behind the weir was measured as well as the water surface elevation in the upstream of the weir.
The analysis indicated that the discharge plays the main role to increase the size of the scour hole. Using the weir with holes helps to decrease the scour occurs behind it, because the flow from holes interrupted the flow fallen from over the weir then some of its energy was dissipated. The diameter of the weir's hole that caused the smallest scour was 0.115 cm, while the most effective distance of the this hole to cause the same effect was 0.5 cm, among all the studied cases. Due to its height increases the dissipation of the energy of the falling flow.