scholarly journals Morphology of Tigris River within Baghdad City

2012 ◽  
Vol 16 (10) ◽  
pp. 3783-3790 ◽  
Author(s):  
A. A. Ali ◽  
N. A. Al-Ansari ◽  
S. Knutsson
Keyword(s):  
Water Resources ◽  
Cross Section ◽  
Field Measurements ◽  
Water Levels ◽  
One Dimensional ◽  
Tigris River ◽  
Diyala River ◽  
The One ◽  
The City ◽  
Gauging Station

Abstract. In recent years, substantial changes have occurred in the morphology of the River Tigris within Baghdad City. Although huge volumes of sediment are being trapped in recently constructed headwater reservoirs, the number of islands in the Tigris at Baghdad is increasing. The debris of bridges destroyed in the wars of 1991 and 2003 and their subsequent reconstruction have enhanced the development of these islands. As a consequence the ability of the river to carry the peaks of flood waters has been reduced. This has led to potential increase of flooding in parts of the city. The bed of the River Tigris has been surveyed on three occasions (1976, 1991, and 2008). The most recent survey was conducted by the Ministry of Water Resources, extended 49 km from the Al-Muthana Bridge north Baghdad to the confluence with the Diyala River south Baghdad. It yielded cross-section profiles at 250 m intervals. The data are used to predict the maximum flood capacity for the river using the one-dimensional hydraulic model for steady flow "HEC-RAS" modeling. Calibration of the model was carried out using field measurements for water levels along the last 15 km of the reach and the last 10 yr of observation at the Sarai Baghdad gauging station. The model showed a significant predicted reduction in the current river capacity below that which the river had carried during the floods of 1971 and 1988. The three surveys conducted on the same reach of the Tigris indicated that the ability of the river to transport water has decreased.

scholarly journals Morphology of Tigris River within Baghdad City

2012 ◽  
Vol 9 (5) ◽  
pp. 5671-5695
Author(s):  
A. A. Ali ◽  
N. A. Al-Ansari ◽  
S. Knutsson
Keyword(s):  
Cross Sections ◽  
Field Measurements ◽  
Water Levels ◽  
Huge Amount ◽  
One Dimensional ◽  
The Past ◽  
Tigris River ◽  
Critical Discharge ◽  
Diyala River ◽  
Flood Waves

Abstract. Changes in the morphology of the River Tigris within Baghdad City are very noticeable in recent years. The number of islands is increasing with time despite the fact that huge amount of sediments are trapped in reservoirs upstream Baghdad City. The debris of destroyed bridges in the wars of 1991 and 2003 had enhanced the development of these islands. As a consequence the ability of the river had been reduced to pass flood waves. This fact caused partial flooding of parts of Baghdad City. Cross sections of the River Tigris were surveyed in three occasions (1976, 1991 and 2008). The last survey conducted in 2008 by Ministry of Water Resources covered 49 km of the river from Al-Muthana Bridge to its confluence with Diyala River at 250 m intervals. The data was used to predict the maximum flood capacity for the river using one-dimensional hydraulic model for steady flow "HEC-RAS". Calibration was carried out for the model using field measurements for water levels along the last 15 km from its reach and the last 10 yr observations at Sarai Baghdad station. The average discharge of the river in Baghdad had been calculated for the past ten years. This value was introduced in the model. Then different scenarios were applied by increasing the discharge in order to find out the critical discharge that can cause inundation. The procedure continued to detect the areas that had been inundated and the water level was recorded. The model showed a significant reduction in the current river capacity in comparison with what the river had used to hold during floods of 1971 and 1988. The three surveys conducted on the same reach of the River Tigris indicated that the capacity of the river to pass water had been decreased. In addition the changes in the morphology of the river cross sections were very clear.

scholarly journals Utilizing Temperature and Brine Inflow Measurements to Constrain Reservoir Parameters During a Salt Heater Test

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1025
Author(s):  
Richard S. Jayne ◽  
Kristopher L. Kuhlman
Keyword(s):  
Nuclear Waste ◽  
Field Measurements ◽  
Chemical Processes ◽  
Nuclear Waste Storage ◽  
One Dimensional ◽  
Waste Storage ◽  
Dimensional Modeling ◽  
Damaged Zone ◽  
The One ◽  
Best Fit

Brine availability in salt has multiple implications for the safety and design of a nuclear waste storage facility. Brine availability includes both the distribution and transport of brine through a damaged zone around boreholes or drifts excavated into the salt. Coupled thermal, hydrological, mechanical, and chemical processes taking place within heated bedded salt are complex; as part of DECOVALEX 2023 Task E this study takes a parsimonious modeling approach utilizing analytical and numerical one-dimensional simulations to match field measurements of temperature and brine inflow around a heater. The one-dimensional modeling results presented arrive at best-fit thermal conductivity of intact salt, and the permeability and porosity of damaged salt of 5.74 W/m·K, 10−17 m2, and ≈ 0.02, respectively.

scholarly journals The Cospectrum of Stress-Carrying Turbulence in the Presence of Surface Gravity Waves

2018 ◽  
Vol 48 (1) ◽  
pp. 29-44 ◽  
Author(s):  
John Trowbridge ◽  
Malcolm Scully ◽  
Christopher R. Sherwood
Keyword(s):  
Spatial Structure ◽  
Gravity Waves ◽  
Reynolds Shear Stress ◽  
Field Measurements ◽  
Surface Gravity ◽  
One Dimensional ◽  
Surface Gravity Waves ◽  
Wave Velocities ◽  
Boundary Layer Turbulence ◽  
The One

AbstractThe cospectrum of the horizontal and vertical turbulent velocity fluctuations, an essential tool for understanding measurements of the turbulent Reynolds shear stress, often departs in the ocean from the shape that has been established in the atmospheric surface layer. Here, we test the hypothesis that this departure is caused by advection of standard boundary layer turbulence by the random oscillatory velocities produced by surface gravity waves. The test is based on a model with two elements. The first is a representation of the spatial structure of the turbulence, guided by rapid distortion theory, and consistent with the one-dimensional cospectra that have been measured in the atmosphere. The second model element is a map of the spatial structure of the turbulence to the temporal fluctuations measured at fixed sensors, assuming advection of frozen turbulence by the velocities associated with surface waves. The model is adapted to removal of the wave velocities from the turbulent fluctuations using spatial filtering. The model is tested against previously published laboratory measurements under wave-free conditions and two new sets of measurements near the seafloor in the coastal ocean in the presence of waves. Although quantitative discrepancies exist, the model captures the dominant features of the laboratory and field measurements, suggesting that the underlying model physics are sound.

An Experimental Verification of a Two-Dimensional Technique for Computing Performance Of Gas-Drive Reservoirs

1963 ◽  
Vol 3 (01) ◽  
pp. 19-27 ◽  
Author(s):  
P.M. Blair ◽  
D.W. Peaceman
Keyword(s):  
Cross Section ◽  
Space Dimension ◽  
Vertical Cross Section ◽  
Low Flow ◽  
Two Dimensional ◽  
Gas Oil ◽  
One Dimensional ◽  
Flow Equations ◽  
The One ◽  
One Space Dimension

Abstract The shape and position of the gas-oil transition zone during downdip displacement of oil by gas has been calculated using flow equations which include the effects of gravity, relative permeability, capillary pressure and compressibility of the fluids. The calculations treat the problem in two space dimensions, and results are compared with data from a laboratory model tilted at 30 degrees and 60 degrees from the horizontal on displacements near and above the maximum rate at which gravity segregation prevents channeling of the gas along the top of the stratum. The good agreement between calculated and experimental results demonstrates the validity of the technique as well as that of the flow equations. Introduction Knowledge of the fluid distribution and movement in and oil reservoirs important in producing operations and estimation of reserves. The history of the oil industry has included steady progress in improving the accuracy of calculations which provide the required knowledge. The earliest method of calculating reservoir performance consisted of material-balance equations based on the assumption that all properties were uniform throughout a reservoir. For many reservoirs such a simple formulation is still the most useful. However, when large pressure and saturation gradients exist in a reservoir, the assumption of uniform values throughout may lead to significant error. To reduce these errors, Buckley and Leverett introduced a displacement equation which considers pressure and saturation gradients. Methods available at that time permitted solutions to the Buckley-Leverett equation in one space dimension; these solutions have been very useful in solving many problems related to the production of oil. However, the one-dimensional methods are not adequate for systems in which saturations vary in directions other than the direction of flow. An example of such a system is the case of gas displacing oil down a dipping stratum in which the gas-oil contact becomes significantly tilted. Of course, the Buckley-Leverett displacement method cannot predict the tilt of the gas-oil contact. Recent improvements of the one-dimensional Buckley-Leverett method achieve some success in predicting the tilt of the gas-oil contact at sufficiently low flow rates. However, at rates high enough that the viscous pressure gradient nearly equals or exceeds the gravity gradient, even these improved one-dimensional methods incorrectly predict the shape and velocity of the contact. Further progress in estimating such fluid movements in a reservoir appears to require consideration of the problem in more than one space dimension. The recent two-dimensional method of Douglas, Peaceman and Rachford appears adaptable to calculate changes with time of the saturation distribution in a vertical cross-section of a reservoir. The movement of saturation contours should represent the moving fluid contacts and include the effects of crossflow due to gravity, as well as variations in the rock and fluid properties. The nonlinear nature of the equations used in the method has prevented proof of the validity of the solutions. Douglas, Peaceman and Rachford made some comparisons with experiment but did not include cases in which gravity was important nor cases involving displacement by the nonwetting phase. Forthesereasons, atestof the two-dimensional method for a case in which these factors are included would be very desirable. The test selected was a comparison of calculated results with those from a carefully controlled laboratory experiment on a model with measured physical properties. The model selected was one in which gas displaced oil down a tilted, rectangular sand pack. The model can be thought of as representing a vertical cross-section taken parallel to the dip of a reservoir. The displacement thus simulates gas displacing oil downdip that might result from gas-cap expansion or gas injection. SPEJ P. 19^

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

2020 ◽  
Vol 26 (2) ◽  
pp. 129-143
Author(s):  
Maysam S Abbas ◽  
Riyadh Z. Azzubaidi
Keyword(s):  
Cross Section ◽  
Discharge Capacity ◽  
Cross Sections ◽  
Flood Plain ◽  
Main Channel ◽  
Water Levels ◽  
Flood Wave ◽  
Tigris River ◽  
Flood Discharge ◽  
Lateral Inflow

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.                                                                                                            

scholarly journals The First Drying Lake in Chile: Causes and Recovery Options

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 290 ◽  
Author(s):  
Rodrigo Valdés-Pineda ◽  
Pablo García-Chevesich ◽  
Juan B. Valdés ◽  
Roberto Pizarro-Tapia
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Environmental Education ◽  
Water Levels ◽  
Small Scale ◽  
Agricultural Irrigation ◽  
Groundwater Model ◽  
Catchment Scale ◽  
Feasible Solutions ◽  
The City

Located southwest of the city of Santiago (Chile), the Aculeo Lagoon used to be an important body of water, providing environmental, social, and economic services to both locals (mostly drinking water and small-scale agricultural irrigation) and tourists who visited the area for fishing, sailing, and other recreational activities. The lagoon dried completely in May of 2018. The phenomenon has been attributed to the current climatic drought. We implemented and calibrated a surface-groundwater model to evaluate the hydrogeologic causes of the lagoon’s disappearance, and to develop feasible solutions. The lagoon’s recovery requires a series of urgent actions, including environmental education and significant investment in infrastructure to import water. Ultimately, there are two goals: bringing back historic water levels and ensuring the sustainability of water resources at the catchment scale.

CALCULATION OF FUSION CROSS-SECTION FOR 3He+6Li SYSTEM AT NEAR BARRIER ENERGIES

2010 ◽  
Vol 19 (01) ◽  
pp. 141-145
Author(s):  
M. MAHDAVI ◽  
T. KOOHROKHI ◽  
B. KALEJI ◽  
B. JALALEE
Keyword(s):  
Cross Section ◽  
Nuclear Fusion ◽  
Theoretical Data ◽  
Fusion Cross Section ◽  
Fusion Plasma ◽  
One Dimensional ◽  
Good Accord ◽  
Correct Formula ◽  
The One

A correct formula for fusion cross-section is proposed for better understanding of light nuclear fusion plasma. It is based on the one-dimensional method. The fusion cross-section and the Maxwellian rate parameters of the 3 He +6 Li system are calculated. The obtained results are in good accord with theoretical data of other researchers.

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