| 1. |
- Al-Ansari, Nadhir, et al.
(författare)
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Nature of the Distributed of the Bed Sediment within Mosul Dam Reservoir, Iraq
- 2013
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Konferensbidrag (refereegranskat)abstract
- Mosul Dam is one of the biggest hydraulic structures in Iraq. It was constructed in 1986 on the Tigris River in the north of Iraq. The initial storage capacity and water surface area of its reservoir reaches 11.11 km3 and 380 km2 respectively at the maximum operation level 330 m a.s.l. The dam was operated in 1986. A total of 56 samples were collected from the bottom of Mosul reservoir covering most of the reservoir area. The results of the analysis of these samples revealed that they were composed of gravel (3.8%), sand (15%), silt (55.5%) and clay (25.7%). The distribution of these sediments indicates that the silt portion represents the highest followed by clay and then sand. However, sand percentages are the highest in the northern zone of the reservoir where the River Tigris enters the reservoir and decreases gradually toward the dam site. In the meantime, silt percentage decreases toward the dam site while the finer fraction (i.e. clay) increases.
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| 2. |
- Al-Ansari, Nadhir, et al.
(författare)
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Sedimentation in the Mosul reservoir of northern Iraq
- 2013
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Ingår i: Journal of Environmental Hydrology. - 1058-3912 .- 1996-7918. ; 21:7, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Mosul Dam is one of the biggest hydraulic structures in Iraq. It was constructed in 1986 on the Tigris River in the north of Iraq for multiple purposes: irrigation, flood control and power generation. The initial storage capacity and water surface area of its reservoir reaches 11.11 km3 and 380 km2 respectively at the maximum operation level 330 m a.s.l. The dam was operated in 1986. Blockage of the intakes of the pump station for North Al-Jazira Irrigation Project in Mosul Dam reservoir has highlighted the importance of sedimentation problems within the reservoir. A total of 56 samples were collected from the bottom of Mosul reservoir covering most of the reservoir area. The results of the analysis of these samples revealed that they were composed of gravel (3.8%), sand (15%), silt (55.5%) and clay (25.7%). The distribution of these sediments indicates that the silt portion represents the highest 77% of the bottom sediments of this reservoir followed by clay (13.5%) and then sand (9.5%). However, sand percentages are the highest in the northern zone of the reservoir where the River Tigris enters the reservoir and decreases gradually toward the dam site. In the meantime, silt percentage decreases toward the dam site while the finer fraction (i.e. clay) increases. Statistically, the average median and mean sizes of the sediments are 2.81 phi (0.142 mm) and 6.1 phi (0.0146 mm) respectively. In addition, the sediments are poorly sorted, nearly symmetrical in skewness and leptokurtic, very leptokurtic, to mesocratic. Finally, it is believed that the geometry and hydrodynamics of the Mosul reservoir, the location of the River Tigris entrance together with the side tributary valleys have played the most important role in the sediments distribution and their characteristics.
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| 3. |
- Issa, Issa E, et al.
(författare)
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Assessment of Sedimentation Characteristics and Capacity Curve for Mosul Dam Reservoir, Iraq
- 2013
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Konferensbidrag (refereegranskat)abstract
- The sedimentation process is the most important problems that affect directly the performance of reservoirs due to the reduction of the storage capacity and possible problems effecting the operation. Thus periodic assessment of the storage capacity and determining sediment deposition patterns is an important issue for operation and management of reservoirs. In this study, bathymetric survey results had been used to assess the characteristics of sedimentation of Mosul Reservoir. It is located on the Tigris River in the north of Iraq. The water surface area of its reservoir is 380 km2 with a designed storage capacity of 11.11 km3 at a maximum operating level (330 m a.s.l). The dam started operating in 1986. No detailed study was yet carried out to assess its reservoir. The present study indicated that the annual sediment deposited in the reservoir is 45.72 × 106 m3year-1 which is divided into 23.2 × 106 and 22.52 × 106 m3year-1 for dead and live zones respectively. This implies the annual reduction rate in the dead and live storage capacities of the reservoir is 0.786% and 0.276% respectively. Furthermore, the stage-storage capacity curves for the future periods (prediction curves) were assessed using 2011 bathymetric survey data.
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| 4. |
- Issa, Issa E., et al.
(författare)
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Assessment sedimentation rate in the Mosul dam reservoir, Iraq
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Mosul dam is one of the biggest hydraulic structures in Iraq that was built on the Tigris River 60 km north-west Mosul city north of Iraq. The water surface area of its reservoir is 380 km2 with a storage capacity of 11.11×109 m3 at a maximum operation level (330 m.a.s.l). The dam became operational in 1986. No study has been conducted to determine the sedimentation rate, storage capacity and new operational curve since that date. To develop an up to date operational curve, a new bathymetric survey was conducted in 2011. The results indicated that the reduction in the storage capacity of the reservoir was 10.29 %. This implies that the annual sedimentation rate within the reservoir was 45.72×106 m3.yr-1 (0.41%) that is less than the average worldwide rate. Consequently, a new operational curve was constructed.
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| 5. |
- Issa, Issa E., et al.
(författare)
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Changes in bed morphology of Mosul dam reservoir
- 2013
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Ingår i: Journal of Advanced Science and Engineering Research. - 2231-8844. ; 3:2, s. 86-95
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Tidskriftsartikel (refereegranskat)abstract
- Mosul dam is one of the biggest hydraulic structures in Iraq. It was constructed on the Tigris River in the north of Iraq for multiple purposes: irrigation, flood control and power generation. The initial storage capacity and water surface area of its reservoir reach 11.11 km3 and 380 km2 respectively at the maximum operation level 330 m.a.s.l. The dam was operated in 1986. Since that time no survey has been conducted to determining the characteristics of sedimentation in the reservoir. Blockage of the intakes of the pump station for North Al-Jazira Irrigation Project in Mosul dam reservoir has highlighted the importance of sedimentation problems within the reservoir.Sediment distribution was studied within the reservoir. A comparison was made between the conditions at the start of the dam operation and a recent bathymetric survey conducted in 2011.The former was achieved using a topographic map scale 1: 50000 dated 1983 which was converted to a triangular irregular network (TIN) format using the Arc/GIS program. The results of the bathymetric survey were also converted to the TIN map format using the above program. Comparison of the two maps shows that the sedimentation magnitude in the upper zone of the reservoir, where the River Tigris enters, was highest and gradually reduced toward Mosul dam site. Maximum deposition thickness within the reservoir was 17.6 m. The thalweg bed slope of the River Tigris within reservoir area changed from 0.65 m.km-1 before dam construction to 0.71 m.km-1 on the 2011 survey. Zones within the
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| 6. |
- Issa, Issa E., et al.
(författare)
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Expected Future of Water resources within Tigris–Euphrates Rivers basin, Iraq
- 2014
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Ingår i: Journal of Water Resource and Protection. - : Scientific Research Publishing, Inc.. - 1945-3094 .- 1945-3108. ; 6:5, s. 421-432
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Tidskriftsartikel (refereegranskat)abstract
- Iraq is one of the riparian countries within basins of Tigris-Euphrates Rivers in the Middle East region. The region is currently facing water shortage problems due to the increase of the demand and climate changes. In the present study, average monthly water flow measurements for 15 stream flow gaging stations within basins of these rivers in Iraq with population growth rate data in some of its part were used to evaluate the reality of the current situation and future challenges of water availability and demand in Iraq. The results showed that Iraq receives annually 70.92 km3 of water 45.4 and 25.52 km3 from River Tigris and Euphrates respectively. An amount of 18.04 km3 of the Tigris water comes from Turkey while 27.36 km3 is supplied by its tributaries inside Iraq. The whole amount of water in the Euphrates Rivers comes outside the Iraqi borders. Annual decrease of the water inflow is 0.1335 km3 year-1 for Tigris and 0.245 km3 year-1 for Euphrates. This implies the annual percentage reduction of inflow rates for the two rivers is 0.294% and 0.960% respectively. Iraq consumes annually 88.89% (63.05 km3) of incoming water from the two rivers, where about 60.43 and 39.57 % are from Rivers Tigris and Euphrates respectively. Water demand increases annually by 1.002 km3; of which 0.5271 km3 and 0.475 km3 within Tigris and Euphrates basins respectively. The average water demand in 2020 will increase to 42.844 km3 year-1 for Tigris basin and for Euphrates 29.225 km3 year-1 (total 72.069 km3 year-1), while water availability will decrease to 63.46 km3 year-1. This means that the overall water shortage will be restricted to 8.61 km3.
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| 7. |
- Issa, Issa E., et al.
(författare)
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Experimental Analysis of Sediment Deposition Due to Backwater Effect up-stream a Reservoir
- 2014
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Ingår i: Journal of Civil Engineering and Architecture. - : David Publishing Company. - 1934-7359 .- 1934-7367. ; 8:9, s. 1185-1193
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Tidskriftsartikel (refereegranskat)abstract
- The phenomenon of aggradation due to sediment accumulation upstream reservoirs had been studied in this research. For this purpose, group of experiments were conducted in a laboratory channel 25 m long, 0.80 m wide and 0.70 m deep. A block was built at the end of the channel to work as a dam to impound water. The channel was supplied with drainage pipes on both sides to release water out in a manner similar to what happens in reservoirs. The bed of the channel was filled with sand of 0.80 mm median sieve diameter and 0.72 geometric standard deviation. The slope was 0.0093 for all experiments. Two sizes of sand were used representing the sediment. The median diameter and geometric standard deviation of the first were 0.365 mm and 0.46 respectively. The second sample had 0.65 mm median diameter and 0.67 standard deviation. A total of seventy experiments were conducted in two groups to examine effect the sediment transport rate, particle size of sediment and flow velocity on aggradation characteristics. The results showed that there is a strong linear direct relationship between aggradation elements (length and depth) with the rate of sediment transport. Group of dimensionless parameters affecting the aggradation characteristics were used to develop empirical equations to predict the length, maximum depth of aggradation and predict transient bed profile. The results of empirical approach were compared with the measurement data and previous numerical method. The results indicated that the percentage error was –19 to 31% for length of aggradation and –21 to 26% for maximum depth of aggradation. The results also showed that the sediment material were deposited closer to the body of the dam when the released water from the dam is higher than the inflow.
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| 8. |
- Issa, Issa E., et al.
(författare)
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Monitoring and Evaluating the Sedimentation Process in Mosul Dam Reservoir Using Trap Efficiency Approaches
- 2015
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Ingår i: Engineering. - : Scientific Research Publishing, Inc.. - 1947-3931 .- 1947-394X. ; 7:4, s. 190-202
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Tidskriftsartikel (refereegranskat)abstract
- Reservoirs are usually exposed to sediment accumulation problems that will lead to reduction in their storage capacity. This problem directly affects the performance of the dams and causes shortage of their useful life. The simplest technique to estimate sediment deposition rate is using sediment rating curve with sediment trapping efficiency (TE) of the reservoir. Many empirical and semi-empirical approaches have been suggested for to determine this term depending on the annual inflow rate, reservoir characteristics and features of the catchments area. In this study six different empirical methods depending on the residence time principle (water retention time) were used. These approaches were reviewed and applied to determine TE of Mosul dam reservoir (MDR) for period 1986 to 2011. The monthly operating data for inflow, outflow and water elevations for MDR were used to determine monthly TE and long-term TE for whole period of MDR using the mentioned methods. Furthermore, the monthly inflow rate for River Tigris upstream MDR, its sediment rating curve and sediment feeding from valleys around MDR were used to estimate the amount sediment coming to the reservoir. The results provided by these methods for TE withsediment coming to MDR were used to compute the amount of sediment deposited in MDR on monthly bases during this period. The results obtained were evaluated using observed bathymetric survey data that had been collected in 2011 after 25 years of the operation of the dam. The results showed all the mentioned methods gave convergent results and they were very close to bathymetric survey results for estimating the volume of sediment deposited especially that proposed by Ward which gave 0.368% percentage error. Furthermore, the result computed using monthly TE gave good agreement if compared with that long-term TE where the percentage error was ranging between −3.229% to 1.674% for monthly adopted data and −4.862% to −2.477% for whole period data. It is believed that this work will help others to use this procedure on other reservoirs.
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| 9. |
- Issa, Issa E., et al.
(författare)
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Mosul Dam Resorvoir Sedimentation Characteristics, Iraq
- 2014
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Ingår i: Journal of Environmental Hydrology. - 1058-3912 .- 1996-7918. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- Sediment transported by rivers and finally deposited in reservoirs directly affects dam performanceand causes a reduction in their storage capacity and hence operating efficiency. In this study, thesedimentation characteristics of Mosul dam reservoir have been evaluated using two topographic mapsof the reservoir area at different times (1986 and 2011) via Arc/GIS software. The dam is located on theTigris River in the northern part of Iraq and started operating in 1986. The water surface area of itsreservoir is 380 km2 with a designed storage capacity of 11.11 km3 at a maximum operating level (330m a.s.l). The results showed that the annual sediment deposition rate is 45.72 × 106 m3 year-1 of which23.2 × 106 and 22.52 × 106 m3 year-1 are in the dead storage and live storage zones respectively. As aconsequence, the live and dead storage zones lost 6.9% and 19.66% respectively of their storagecapacity during the 25 year of operation of the dam. The water-spread area (water surface area) of thereservoir at dead storage level (300 m a.s.l) was reduced annually by about 1.34 km2. Furthermore,the stage-storage capacity curves for future periods (prediction curves) were assessed and comparedwith adopted prediction curves using 2011 bathymetric survey data.
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| 10. |
- Issa, Issa E., et al.
(författare)
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Sediment delivered in the upper part of Mosul reservoir using physical model
- 2012
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Ingår i: Journal of Civil Engineering and Architecture. - 1934-7359 .- 1934-7367. ; 6:11, s. 1544-1550
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Tidskriftsartikel (refereegranskat)abstract
- Mosul dam is the biggest hydraulic structure in Iraq located on the River Tigris 60 km northwest of Mosul city. Its storage capacity is 11.11 × 109 m3 and it had been in operation since 1986. A physical distorted model with movable bed having a vertical scale 1:100 and a horizontal scale 1:1000 was used to conduct the experiments relating the water level at the reservoir and water discharge upstream the reservoir with the bed load transport rate. The model represents the first 15 km of most northern part of Mosul dam reservoir. The construction of the model was based on bathymetric survey conducted in 2009. Twenty-four experiments were executed using four different discharges (0.5, 1.0, 1.5, and 2.0 L/s) which represent the average discharges in the flood period of River Tigris. At each individual discharge six operations were assumed where the reservoir’s water level was 305, 307, 309, 310, 312, 315 meters above sea level respectively. In all the experiments conducted, bedload transport was measured in the physical model at section representing the River Tigris 1 km upstream the reservoir. The results showed that the bedload rate was decreasing when the water level within the reservoir was increasing. It was also evident that bedload transport rate dramatically decreased at level 310 meter above sea level onward. This is due to the fact that at this level represent the effect of backwater which was noticeable on the river cross section.
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