Using Helley-Smith sampler, 288 bed load samples were collected from 16 cross sections along 18 k... more Using Helley-Smith sampler, 288 bed load samples were collected from 16 cross sections along 18 km reach length of Tigris River within Baghdad. The spatial distribution of sampling along the reach ...
Dokan is a multipurpose dam located on the Lesser Zab River in the Iraq/Kurdistan region. The dam... more Dokan is a multipurpose dam located on the Lesser Zab River in the Iraq/Kurdistan region. The dam has operated since 1959, and it drains an area of 11,690 km 2. All reservoirs in the world suffer from sediment deposition. It is one of the main problems for reservoir life sustainability. Sustainable reservoir sediment-management practices enable the reservoir to function for a longer period of time by reducing reservoir sedimentation. This study aims to assess the annual runoff and sediment loads of the Dokan Dam watershed using the soil and water assessment tool (SWAT) model to evaluate the relative contributions in comparison with the total values delivered from both watershed and Lesser Zab River and to identify the basins with a high sediment load per unit area. These help in the process of developing a plan and strategy to manage sediment inflow and deposition. The SUFI-2 program was applied for a model calibrated based on the available field measurements of the adjacent Derbendekhan Dam watershed, which has similar geological formations, characteristics and weather. For the calibration period (1961-1968), the considered statistical criteria of determination coefficients and Nash-Sutcliffe model efficiency were 0.75 and 0.64 for runoff while the coefficients were 0.65 and 0.63 for sediment load, respectively. The regionalization technique for parameter transformation from Derbendekhan to Dokan watershed was applied. Furthermore, the model was validated based on transformed parameters and the available observed flow at the Dokan watershed for the period (1961-1964); they gave reasonable results for the determination coefficients and Nash-Sutcliffe model efficiency, which were 0.68 and 0.64, respectively. The results of SWAT project simulation for Dokan watershed for the period (1959-2014) indicated that the average annual runoff volume which entered the reservoir was about 2100 million cubic meters (MCM). The total sediment delivered to the reservoir was about 72 MCM over the 56 years of dam life, which is equivalent to 10% of the reservoir dead storage. Two regression formulas were presented to correlate the annual runoff volume and sediment load with annual rain depth for the studied area. In addition, a spatial distribution of average annual sediment load was constructed to identify the sub basin of the high contribution of sediment load.
River Tigris is a major river in Iraq. Sediment at the bed of the river within a reach of about 1... more River Tigris is a major river in Iraq. Sediment at the bed of the river within a reach of about 18 km from the center of Baghdad upstream was investigated. Sixty five cross sections were surveyed, and 46 sediment samples were collected and analyzed. It was noticed that fine sand was dominant in the bed (90.74%). The average median size within the reach was 2.49 phi (0.177 mm), while the mean size was 2.58 phi (0.16 mm). In addition, the sediments were moderately sorted, fine skewed and leptokurtic. The size of the bed sediment decreased relative to previous investigations due to the construction of the Adhaim dam on tributary, which used to be the main sediment supplier to the Tigris River before entering Baghdad. Furthermore, the discharge of the Tigris River for the period 1983–2013 (715 m3/s) decreased by about 40% and 30%since 1983when compared with the periods 1931–1956 (1208 m3/s) and 1956–1980 (1015 m3/s), respectively, due to climate change and construction of dams upstream ...
ABSTRACT Iraq is located in the Middle East. It covers an area of 433,970 square kilometres popul... more ABSTRACT Iraq is located in the Middle East. It covers an area of 433,970 square kilometres populated by about 32 million inhabitants. Iraq greatly relies in its water resources on the Tigris and Euphrates Rivers. Recently, Iraq is suffering from water shortage problems. This is due to external and internal factors. The former includes global warming and water resources policies of neighbouring countries while the latter includes mismanagement of its water resources. The supply and demand are predicted to be 43 and 66.8 Billion Cubic Meters (BCM) respectively in 2015, while in 2025 it will be 17.61 and 77 BCM respectively. In addition, future prediction suggests that Tigris and Euphrates Rivers will be completely dry in 2040. To overcome this problem, prudent water management policies are to be adopted. This includes Strategic Water Management Vision, development of irrigation techniques, reduction of water losses, use of non-conve
Growing islands became noticeable phenomena in the channel of River Tigris within Baghdad City du... more Growing islands became noticeable phenomena in the channel of River Tigris within Baghdad City during recent years. Despite the fact that large amount of sediments are trapped in reservoirs on the River Tigris and its tributaries the number of islands are increasing with time. This is due to the debris of destroyed bridges in the wars of 1991 and 2003. As a consequence the ability of the river had been reduced to pass flood waves. This fact caused flooding parts of major cities like Baghdad. Cross sections of the River Tigris were surveyed in different occasions (1976, 1991 and 2008). In 1976 the survey was conducted by Geohydraulique and in 1991 by University of Technology – Baghdad (extended for the previous study). The last survey was conducted in 2008 by Ministry of Water Resources extending 49 kilometers from Al-Muthana Bridge till the confluence with Diyala River at intervals having average horizontal spacing of 250m. The data was used to predict the maximum flood capacity for...
The goal of this study is to obtain the required quantities of water for purpose of restorated va... more The goal of this study is to obtain the required quantities of water for purpose of restorated varied areas of it within the new boundaries for the marsh. The volume-elevation and elevation-area relationships were built from a digital elevation model (DEM) where these relationships were used as a part of a water balance model together with the evapo-transpiration losses to compute the required inflow into the marsh for three restoration plans suitable for wet, moderate and dry years. The required inflows were distributed over the feeding sources for the marsh which they are mainly irrigation canals for agricultural projects inside the marsh area according to their design capacities and the surplus water sharing in term of three scenarios for the previous restoration strategies. A new feeding source was proposed near Al-Fuhood village on the Euphrates river which will supplied the marsh in case of flooding the river, also an expansion for Al-Kurmashia River head regulator was propose...
A hydrological routing study for Abu Zirig Marsh was carried out to estimate the hydrological sta... more A hydrological routing study for Abu Zirig Marsh was carried out to estimate the hydrological state within the marsh for the Present and future conditions of the marsh. The water surface elevation, area and storage within the marsh at the present and for the future conditions were estimated and the effect of uncontrolling outlets on the hydrological and water quality state of the marsh at the present conditions was specified. The salt mass balance equation was used to estimate the inflow and outflow discharges that required for reducing the effect of evapotranspiration on the water quality and flashing out the accumulated mass of salts and then improving the marsh water quality. This equation was applied on the future conditions of the marsh and inflow and outflow discharges that required for this purposes were estimated. The results of the hydrological routing for the present conditions showed that the maximum water surface area is 79 km 2 which occur during Spring. While it is bet...
The Iraqi marsh lands, which are known as the Garden of Eden, cover an area about 15-20 10 3 km 2... more The Iraqi marsh lands, which are known as the Garden of Eden, cover an area about 15-20 10 3 km 2 in the lower part of the Mesopotamian basin. The area had played a prominent part in the history of mankind and was inhabited since the dawn of civilization. The Iraqi government started to drain the marshes for political and military reasons and at 2000 less than 10% of the marshes remained. After 2003, the process of restoration and rehabilitation of Iraqi marshes started. There are number of difficulties encountered in the process. In this research we would like to explore the possibilities of restoring the Iraqi marshes. It is believed that 70-75% of the original areas of the marshes can be restored. This implies that 13km 3 water should be available to achieve this goal keeping the water quality as it is. To evaluate the water quality in the marshes, 154 samples were collected at 48 stations during summer, spring and winter. All the results indicate that the water quality was bad. ...
Tigris and Euphrates rivers represent the artery of life in Iraq. Tigris River rises from Turkey ... more Tigris and Euphrates rivers represent the artery of life in Iraq. Tigris River rises from Turkey and flows toward the southeast to enter Iraq. It drains a catchment area of 473 100 km2 of which about 58% lies in Iraq. In this study the reach, about 50 km long, of the river inside Baghdad was been studied. It starts at Al- Muthana Bridge and ends at Tigris-Diyala River confluence. Generally, the river reach is part of an alluvial plain, single channel and meandering. The bed material of the river is composed mainly of fine sand and small portion of silt and clay. Other significant features of the reach are the growing islands and bank depositions. Recently water resources of Iraq are negatively affected by climatic changes and the huge water projects in the riparian countries. As a result, the flow of Tigris River at Baghdad city has significantly decreased where the average monthly flow is 520 m3/s for the period 2000-2012 which represents about 50% reduction compared to previous pe...
River Tigris divides Baghdad, capital of Iraq, in two parts. The reach of the river within Baghda... more River Tigris divides Baghdad, capital of Iraq, in two parts. The reach of the river within Baghdad is about 60 km long. Many islands and bars are obstructing the flow of the river within Baghdad. To overcome this problem, dredging operations started along most of Tigris River inside Baghdad City to remove many islands and side bars, which reduced the flooding capacity and the efficiency of water intakes. An examination for the dredging plan under process and two proposed additional plans was performed using the Hydrologic Engineering Centers River Analysis System software (HEC-RAS) for a 50 km long river reach to investigate whether they can recover the designed flooding capacity of the river or just improving it. Calibration and verification processes were implemented in the model using observed water levels at Sarai Baghdad gauging station and along the last 15 km of the river reach. Comparisons of computed water levels were conducted with those of previous studies and historical data. Some improvement of flood capacity was achieved based on the recorded data of the last three decades. Cautions about the water intakes should be considered to maintain their function with the expected drop in water level due to dredging operations.
Iraq is part of the Middle East and North Africa (MENA region). It greatly relies in its water re... more Iraq is part of the Middle East and North Africa (MENA region). It greatly relies in its water resources on the Tigris and Euphrates Rivers. Iraq was considered rich in its water resources till 1970s. After that problems due to water scarcity aroused. Recently, it is expected that water shortage problems will be more serious. The supply and demand are predicted to be 43 and 66.8 Billion Cubic Meters (BCM) respectively in 2015, while in 2025 it will be 17.61 and 77BCM respectively. In addition, future prediction suggests that Tigris and Euphrates Rivers will be completely dry in 2040. To overcome this problem, prudent water management plan is to be adopted. It should include Strategic Water Management Vision, development of irrigation techniques, reduction of water losses, use of non-conventional water resources and research and development planning.
In recent years, substantial changes have occurred in the morphology of the River Tigris within B... more 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.
International Journal of River Basin Management, 2019
The Tigris River in Baghdad is a large sand-bed river, supply-limited because of the implementati... more The Tigris River in Baghdad is a large sand-bed river, supply-limited because of the implementation of a water flow regulation scheme comprising a series of reservoirs and barrages. The significant reduction in the water discharge has affected the hydraulic performance of the river and turned it into an under-fit river of complicated morphology where many islands and bank deposits have been showed up across an 18 km reach in addition to the essential sinuosity. Measuring sediment load at individual cross-sections in the river gives misleading estimates and the corresponding sediment rating curve has a locally limited using. A spatially sediment rating by investigating sediment loads over the complicated reach is required to overcome the local limitations. Sediment transport rates have been investigated at 16 cross-sections along the study reach by collecting suspended load, bed load and bed material samples. Velocity profiles were measured at the sampling stations using an Acoustic Doppler Current Profiler (ADCP). The measurement results indicated that the suspended load is the dominant mode of transport (93.5%). However, bedloads were considered in determining the total loads. A spatial total load rating curve in the form of a power function was established and examined against the sediment measurements. Twenty-two previously published total load formulae where applied at the same sections and of these the Colby 1964 formula gave the closest fit to the measured loads. Based on the results from this study a recommended procedure is established for using a spatial total load rating curve to estimate sediment transport rates for similar morphologically complicated rivers. Average annual transport rates during the period 2009-13 was estimated at 3.21 million tons.
The River Tigris is a major river in Iraq. It divides Baghdad, the capital of Iraq, in two parts.... more The River Tigris is a major river in Iraq. It divides Baghdad, the capital of Iraq, in two parts. The reach of the river within Baghdad is about 60 km long. The climate change within the region and ...
Using Helley-Smith sampler, 288 bed load samples were collected from 16 cross sections along 18 k... more Using Helley-Smith sampler, 288 bed load samples were collected from 16 cross sections along 18 km reach length of Tigris River within Baghdad. The spatial distribution of sampling along the reach ...
Dokan is a multipurpose dam located on the Lesser Zab River in the Iraq/Kurdistan region. The dam... more Dokan is a multipurpose dam located on the Lesser Zab River in the Iraq/Kurdistan region. The dam has operated since 1959, and it drains an area of 11,690 km 2. All reservoirs in the world suffer from sediment deposition. It is one of the main problems for reservoir life sustainability. Sustainable reservoir sediment-management practices enable the reservoir to function for a longer period of time by reducing reservoir sedimentation. This study aims to assess the annual runoff and sediment loads of the Dokan Dam watershed using the soil and water assessment tool (SWAT) model to evaluate the relative contributions in comparison with the total values delivered from both watershed and Lesser Zab River and to identify the basins with a high sediment load per unit area. These help in the process of developing a plan and strategy to manage sediment inflow and deposition. The SUFI-2 program was applied for a model calibrated based on the available field measurements of the adjacent Derbendekhan Dam watershed, which has similar geological formations, characteristics and weather. For the calibration period (1961-1968), the considered statistical criteria of determination coefficients and Nash-Sutcliffe model efficiency were 0.75 and 0.64 for runoff while the coefficients were 0.65 and 0.63 for sediment load, respectively. The regionalization technique for parameter transformation from Derbendekhan to Dokan watershed was applied. Furthermore, the model was validated based on transformed parameters and the available observed flow at the Dokan watershed for the period (1961-1964); they gave reasonable results for the determination coefficients and Nash-Sutcliffe model efficiency, which were 0.68 and 0.64, respectively. The results of SWAT project simulation for Dokan watershed for the period (1959-2014) indicated that the average annual runoff volume which entered the reservoir was about 2100 million cubic meters (MCM). The total sediment delivered to the reservoir was about 72 MCM over the 56 years of dam life, which is equivalent to 10% of the reservoir dead storage. Two regression formulas were presented to correlate the annual runoff volume and sediment load with annual rain depth for the studied area. In addition, a spatial distribution of average annual sediment load was constructed to identify the sub basin of the high contribution of sediment load.
River Tigris is a major river in Iraq. Sediment at the bed of the river within a reach of about 1... more River Tigris is a major river in Iraq. Sediment at the bed of the river within a reach of about 18 km from the center of Baghdad upstream was investigated. Sixty five cross sections were surveyed, and 46 sediment samples were collected and analyzed. It was noticed that fine sand was dominant in the bed (90.74%). The average median size within the reach was 2.49 phi (0.177 mm), while the mean size was 2.58 phi (0.16 mm). In addition, the sediments were moderately sorted, fine skewed and leptokurtic. The size of the bed sediment decreased relative to previous investigations due to the construction of the Adhaim dam on tributary, which used to be the main sediment supplier to the Tigris River before entering Baghdad. Furthermore, the discharge of the Tigris River for the period 1983–2013 (715 m3/s) decreased by about 40% and 30%since 1983when compared with the periods 1931–1956 (1208 m3/s) and 1956–1980 (1015 m3/s), respectively, due to climate change and construction of dams upstream ...
ABSTRACT Iraq is located in the Middle East. It covers an area of 433,970 square kilometres popul... more ABSTRACT Iraq is located in the Middle East. It covers an area of 433,970 square kilometres populated by about 32 million inhabitants. Iraq greatly relies in its water resources on the Tigris and Euphrates Rivers. Recently, Iraq is suffering from water shortage problems. This is due to external and internal factors. The former includes global warming and water resources policies of neighbouring countries while the latter includes mismanagement of its water resources. The supply and demand are predicted to be 43 and 66.8 Billion Cubic Meters (BCM) respectively in 2015, while in 2025 it will be 17.61 and 77 BCM respectively. In addition, future prediction suggests that Tigris and Euphrates Rivers will be completely dry in 2040. To overcome this problem, prudent water management policies are to be adopted. This includes Strategic Water Management Vision, development of irrigation techniques, reduction of water losses, use of non-conve
Growing islands became noticeable phenomena in the channel of River Tigris within Baghdad City du... more Growing islands became noticeable phenomena in the channel of River Tigris within Baghdad City during recent years. Despite the fact that large amount of sediments are trapped in reservoirs on the River Tigris and its tributaries the number of islands are increasing with time. This is due to the debris of destroyed bridges in the wars of 1991 and 2003. As a consequence the ability of the river had been reduced to pass flood waves. This fact caused flooding parts of major cities like Baghdad. Cross sections of the River Tigris were surveyed in different occasions (1976, 1991 and 2008). In 1976 the survey was conducted by Geohydraulique and in 1991 by University of Technology – Baghdad (extended for the previous study). The last survey was conducted in 2008 by Ministry of Water Resources extending 49 kilometers from Al-Muthana Bridge till the confluence with Diyala River at intervals having average horizontal spacing of 250m. The data was used to predict the maximum flood capacity for...
The goal of this study is to obtain the required quantities of water for purpose of restorated va... more The goal of this study is to obtain the required quantities of water for purpose of restorated varied areas of it within the new boundaries for the marsh. The volume-elevation and elevation-area relationships were built from a digital elevation model (DEM) where these relationships were used as a part of a water balance model together with the evapo-transpiration losses to compute the required inflow into the marsh for three restoration plans suitable for wet, moderate and dry years. The required inflows were distributed over the feeding sources for the marsh which they are mainly irrigation canals for agricultural projects inside the marsh area according to their design capacities and the surplus water sharing in term of three scenarios for the previous restoration strategies. A new feeding source was proposed near Al-Fuhood village on the Euphrates river which will supplied the marsh in case of flooding the river, also an expansion for Al-Kurmashia River head regulator was propose...
A hydrological routing study for Abu Zirig Marsh was carried out to estimate the hydrological sta... more A hydrological routing study for Abu Zirig Marsh was carried out to estimate the hydrological state within the marsh for the Present and future conditions of the marsh. The water surface elevation, area and storage within the marsh at the present and for the future conditions were estimated and the effect of uncontrolling outlets on the hydrological and water quality state of the marsh at the present conditions was specified. The salt mass balance equation was used to estimate the inflow and outflow discharges that required for reducing the effect of evapotranspiration on the water quality and flashing out the accumulated mass of salts and then improving the marsh water quality. This equation was applied on the future conditions of the marsh and inflow and outflow discharges that required for this purposes were estimated. The results of the hydrological routing for the present conditions showed that the maximum water surface area is 79 km 2 which occur during Spring. While it is bet...
The Iraqi marsh lands, which are known as the Garden of Eden, cover an area about 15-20 10 3 km 2... more The Iraqi marsh lands, which are known as the Garden of Eden, cover an area about 15-20 10 3 km 2 in the lower part of the Mesopotamian basin. The area had played a prominent part in the history of mankind and was inhabited since the dawn of civilization. The Iraqi government started to drain the marshes for political and military reasons and at 2000 less than 10% of the marshes remained. After 2003, the process of restoration and rehabilitation of Iraqi marshes started. There are number of difficulties encountered in the process. In this research we would like to explore the possibilities of restoring the Iraqi marshes. It is believed that 70-75% of the original areas of the marshes can be restored. This implies that 13km 3 water should be available to achieve this goal keeping the water quality as it is. To evaluate the water quality in the marshes, 154 samples were collected at 48 stations during summer, spring and winter. All the results indicate that the water quality was bad. ...
Tigris and Euphrates rivers represent the artery of life in Iraq. Tigris River rises from Turkey ... more Tigris and Euphrates rivers represent the artery of life in Iraq. Tigris River rises from Turkey and flows toward the southeast to enter Iraq. It drains a catchment area of 473 100 km2 of which about 58% lies in Iraq. In this study the reach, about 50 km long, of the river inside Baghdad was been studied. It starts at Al- Muthana Bridge and ends at Tigris-Diyala River confluence. Generally, the river reach is part of an alluvial plain, single channel and meandering. The bed material of the river is composed mainly of fine sand and small portion of silt and clay. Other significant features of the reach are the growing islands and bank depositions. Recently water resources of Iraq are negatively affected by climatic changes and the huge water projects in the riparian countries. As a result, the flow of Tigris River at Baghdad city has significantly decreased where the average monthly flow is 520 m3/s for the period 2000-2012 which represents about 50% reduction compared to previous pe...
River Tigris divides Baghdad, capital of Iraq, in two parts. The reach of the river within Baghda... more River Tigris divides Baghdad, capital of Iraq, in two parts. The reach of the river within Baghdad is about 60 km long. Many islands and bars are obstructing the flow of the river within Baghdad. To overcome this problem, dredging operations started along most of Tigris River inside Baghdad City to remove many islands and side bars, which reduced the flooding capacity and the efficiency of water intakes. An examination for the dredging plan under process and two proposed additional plans was performed using the Hydrologic Engineering Centers River Analysis System software (HEC-RAS) for a 50 km long river reach to investigate whether they can recover the designed flooding capacity of the river or just improving it. Calibration and verification processes were implemented in the model using observed water levels at Sarai Baghdad gauging station and along the last 15 km of the river reach. Comparisons of computed water levels were conducted with those of previous studies and historical data. Some improvement of flood capacity was achieved based on the recorded data of the last three decades. Cautions about the water intakes should be considered to maintain their function with the expected drop in water level due to dredging operations.
Iraq is part of the Middle East and North Africa (MENA region). It greatly relies in its water re... more Iraq is part of the Middle East and North Africa (MENA region). It greatly relies in its water resources on the Tigris and Euphrates Rivers. Iraq was considered rich in its water resources till 1970s. After that problems due to water scarcity aroused. Recently, it is expected that water shortage problems will be more serious. The supply and demand are predicted to be 43 and 66.8 Billion Cubic Meters (BCM) respectively in 2015, while in 2025 it will be 17.61 and 77BCM respectively. In addition, future prediction suggests that Tigris and Euphrates Rivers will be completely dry in 2040. To overcome this problem, prudent water management plan is to be adopted. It should include Strategic Water Management Vision, development of irrigation techniques, reduction of water losses, use of non-conventional water resources and research and development planning.
In recent years, substantial changes have occurred in the morphology of the River Tigris within B... more 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.
International Journal of River Basin Management, 2019
The Tigris River in Baghdad is a large sand-bed river, supply-limited because of the implementati... more The Tigris River in Baghdad is a large sand-bed river, supply-limited because of the implementation of a water flow regulation scheme comprising a series of reservoirs and barrages. The significant reduction in the water discharge has affected the hydraulic performance of the river and turned it into an under-fit river of complicated morphology where many islands and bank deposits have been showed up across an 18 km reach in addition to the essential sinuosity. Measuring sediment load at individual cross-sections in the river gives misleading estimates and the corresponding sediment rating curve has a locally limited using. A spatially sediment rating by investigating sediment loads over the complicated reach is required to overcome the local limitations. Sediment transport rates have been investigated at 16 cross-sections along the study reach by collecting suspended load, bed load and bed material samples. Velocity profiles were measured at the sampling stations using an Acoustic Doppler Current Profiler (ADCP). The measurement results indicated that the suspended load is the dominant mode of transport (93.5%). However, bedloads were considered in determining the total loads. A spatial total load rating curve in the form of a power function was established and examined against the sediment measurements. Twenty-two previously published total load formulae where applied at the same sections and of these the Colby 1964 formula gave the closest fit to the measured loads. Based on the results from this study a recommended procedure is established for using a spatial total load rating curve to estimate sediment transport rates for similar morphologically complicated rivers. Average annual transport rates during the period 2009-13 was estimated at 3.21 million tons.
The River Tigris is a major river in Iraq. It divides Baghdad, the capital of Iraq, in two parts.... more The River Tigris is a major river in Iraq. It divides Baghdad, the capital of Iraq, in two parts. The reach of the river within Baghdad is about 60 km long. The climate change within the region and ...
The River Tigris is a major river in Iraq. It divides Baghdad, the capital of Iraq, in two parts.... more The River Tigris is a major river in Iraq. It divides Baghdad, the capital of Iraq, in two parts. The reach of the river within Baghdad is about 60 km long. The climate change within the region and the construction of hydraulic structures upstream of Baghdad has reduced the water discharge of the river by 44%. Despite the fact that huge volumes of sediment have been trapped in the constructed headwater reservoirs, substantial changes have occurred in the topography of the Tigris River within Baghdad City and the number of depositions is increasing. The debris of the destroyed bridges from the wars of 1991 and 2003 and their subsequent reconstruction have contributed to the development of these depositions. As a consequence, the ability of the river to carry the peak flood waters has been reduced. This has led to a potential increase of flooding in parts of the city. To predict the maximum flood capacity for the river, the bathymetric survey that was conducted for 50 km of the Tigris River by the Ministry of Water Resources in 2008 has been used with the one-dimensional flow model “HEC-RAS”. Calibration of the model was carried out using field measurements for water levels along the last 15 km of the reach, and the water level observations at the Sarai Baghdad gauging station for the last 10 years were used to validate the model. The model showed a significant reduction in the river’s capacity compared with what the river had carried during the floods of 1971 and 1988. This result agrees with previous surveys conducted on the same reach indicating that the ability of the river to convey high water has decreased. To overcome this problem, dredging operations started along most of the Tigris River inside Baghdad City to remove many islands and side bars, as well as cleaning water intakes. An examination for the dredging plan currently in progress and two additional proposed plans was conducted using the ‘HEC-RAS’ model for the 50 km long river reach to investigate whether the designed flooding capacity of the river can be recovered and how much it can be improved. Comparing the historical records of water level and discharge for the last three decades, some improvement of flood capacity was achieved. Cautions about the water intakes should be considered to maintain their functionalities with the expected drop in water levels due to dredging operations. Bathymetric and land surveys were conducted for the northern Tigris River reach (18 km length) in Baghdad, producing 180 cross sections. A riverbed topography map was established from these cross sections. Sediment transport rates and bed composition were investigated by collecting three different types of sediment samples at the quartiles of 16 cross sections along this reach. The Helley-Smith sampler was used to collect 288 bedload samples, a suction pump was used to collect 212 suspended load samples from different depths. The Van Veen grab was used to collect 46 bed material samples. The velocity profiles and the water discharges were measured using ADCP at the sampling sections. Bed sediment compositions were investigated by analysing the collected bed material samples. It was noticed that fine sand dominated the riverbed (90.74%). The average median size within the reach was 2.49 phi (0.177mm) whilst the mean size was 2.58 phi (0.16mm). In addition, the sediments were moderately sorted, fine skewed and leptokurtic. The size of the bed sediment relatively decreased compared to older investigations due to the decrease of the competence of the river. The bed elevation had increased compared to previous surveys. It was noticed that dredging operations and obstacles (e.g. fallen bridges and islands) disturbed the flow of the river and the sediment characteristics in several sites. Bedload rates were computed using the weights of the collected bedload samples. The spatial distribution of sampling cross sections took into consideration the variance of river topography where 7 meanders, 2 islands and several bank depositions characterize the geometry of the river reach. Twenty bedload predictors were applied to the same reach. The annual transported quantities of the bedload were estimated to be 36 and 50 thousand tons in 2009 and 2013 respectively. The total load discharge rate in the northern reach of the Tigris River was computed using the sediment concentrations of the collected suspended load samples after adding the bedload rate at each of the sampling cross sections. The results indicated that the suspended load is the dominant mode in the total load with a minimum percentage of 93.5%. The total load ranged from 29.1 to 190.3 kg/s. A total load rating curve of the power function was established. The associated errors from using the proposed rating curve are within reassuring levels and less than the errors produced from most of the other twenty-two total load formulas, which were applied to the same reach. The scattering of the results from the other formulas can be attributed to the spatial variance in the topography of the riverbed. According to the final results obtained, it is recommended to use the proposed procedure for establishing a spatial total load rating curve to estimate sediment rates for morphologically complicated rivers. The annual transported quantities of the total load were estimated at 2.47 and 4.23 million tons for 2009 and 2013 respectively. The three-dimensional morphodynamic model (Simulation of Sediment movements In water Intakes with Multiblock option - SSIIM) was used to simulate the velocity field and the water surface profile along the northern reach of the Tigris River using the findings of the current bathymetric survey of the river. The model was calibrated for the water levels, the velocity profiles and the sediment concentration profiles using different combinations of parameters and algorithms, those available in the model. The set of parameters that gave a minimum root mean square error (RMSE) was used for the validation process using another set of field measurements. The calibration and the validation results showed good agreement with field measurements, and the model was used to predict the future changes in river hydro-morphology for a period of 14 months. The results of the future predictions showed increases in depositions on the shallow part of the cross section having lower velocity and, on the other hand, the river deepens the incised route to fit its current hydrologic condition leaving the former wide section as a floodplain for the newer river. The net deposition/erosion rate was 67.44 kg/s in average and the total deposition quantity was 2.12 million tons annually. The locations of depositions are compatible with those of the river in the real world. An expansion in the size of current islands was predicted. An indication of the potential threats of the river banks’ collapse and the bridge piers’ instability was given by high erosion along the thalweg line.
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Papers by Ammar Ali
As a consequence, the ability of the river to carry the peak flood waters has been reduced. This has led to a potential increase of flooding in parts of the city. To predict the maximum flood capacity for the river, the bathymetric survey that was conducted for 50 km of the Tigris River by the Ministry of Water Resources in 2008 has been used with the one-dimensional flow model “HEC-RAS”. Calibration of the model was carried out using field measurements for water levels along the last 15 km of the reach, and the water level observations at the Sarai Baghdad gauging station for the last 10 years were used to validate the model. The model showed a significant reduction in the river’s capacity compared with what the river had carried during the floods of 1971 and 1988. This result agrees with previous surveys conducted on the same reach indicating that the ability of the river to convey high water has decreased.
To overcome this problem, dredging operations started along most of the Tigris River inside Baghdad City to remove many islands and side bars, as well as cleaning water intakes. An examination for the dredging plan currently in progress and two additional proposed plans was conducted using the ‘HEC-RAS’ model for the 50 km long river reach to investigate whether the designed flooding capacity of the river can be recovered and how much it can be improved. Comparing the historical records of water level and discharge for the last three decades, some improvement of flood capacity was achieved. Cautions about the water intakes should be considered to maintain their functionalities with the expected drop in water levels due to dredging operations.
Bathymetric and land surveys were conducted for the northern Tigris River reach (18 km length) in Baghdad, producing 180 cross sections. A riverbed topography map was established from these cross sections. Sediment transport rates and bed composition were investigated by collecting three different types of sediment samples at the quartiles of 16 cross sections along this reach. The Helley-Smith sampler was used to collect 288 bedload samples, a suction pump was used to collect 212 suspended load samples from different depths. The Van Veen grab was used to collect 46 bed material samples. The velocity profiles and the water discharges were measured using ADCP at the sampling sections.
Bed sediment compositions were investigated by analysing the collected bed material samples. It was noticed that fine sand dominated the riverbed (90.74%). The average median size within the reach was 2.49 phi (0.177mm) whilst the mean size was 2.58 phi (0.16mm). In addition, the sediments were moderately sorted, fine skewed and leptokurtic. The size of the bed sediment relatively decreased compared to older investigations due to the decrease of the competence of the river. The bed elevation had increased compared to previous surveys. It was noticed that dredging operations and obstacles (e.g. fallen bridges and islands) disturbed the flow of the river and the sediment characteristics in several sites.
Bedload rates were computed using the weights of the collected bedload samples. The spatial distribution of sampling cross sections took into consideration the variance of river topography where 7 meanders, 2 islands and several bank depositions characterize the geometry of the river reach. Twenty bedload predictors were applied to the same reach. The annual transported quantities of the bedload were estimated to be 36 and 50 thousand tons in 2009 and 2013 respectively.
The total load discharge rate in the northern reach of the Tigris River was computed using the sediment concentrations of the collected suspended load samples after adding the bedload rate at each of the sampling cross sections. The results indicated that the suspended load is the dominant mode in the total load with a minimum percentage of 93.5%. The total load ranged from 29.1 to 190.3 kg/s. A total load rating curve of the power function was established. The associated errors from using the proposed rating curve are within reassuring levels and less than the errors produced from most of the other twenty-two total load formulas, which were applied to the same reach. The scattering of the results from the other formulas can be attributed to the spatial variance in the topography of the riverbed. According to the final results obtained, it is recommended to use the proposed procedure for establishing a spatial total load rating curve to estimate sediment rates for morphologically complicated rivers. The annual transported quantities of the total load were estimated at 2.47 and 4.23 million tons for 2009 and 2013 respectively.
The three-dimensional morphodynamic model (Simulation of Sediment movements In water Intakes with Multiblock option - SSIIM) was used to simulate the velocity field and the water surface profile along the northern reach of the Tigris River using the findings of the current bathymetric survey of the river. The model was calibrated for the water levels, the velocity profiles and the sediment concentration profiles using different combinations of parameters and algorithms, those available in the model. The set of parameters that gave a minimum root mean square error (RMSE) was used for the validation process using another set of field measurements. The calibration and the validation results showed good agreement with field measurements, and the model was used to predict the future changes in river hydro-morphology for a period of 14 months. The results of the future predictions showed increases in depositions on the shallow part of the cross section having lower velocity and, on the other hand, the river deepens the incised route to fit its current hydrologic condition leaving the former wide section as a floodplain for the newer river. The net deposition/erosion rate was 67.44 kg/s in average and the total deposition quantity was 2.12 million tons annually. The locations of depositions are compatible with those of the river in the real world. An expansion in the size of current islands was predicted. An indication of the potential threats of the river banks’ collapse and the bridge piers’ instability was given by high erosion along the thalweg line.