Preface
Mohammad
Karamouz
author
text
article
2007
per
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
0
1
https://www.iwrr.ir/article_15975_2c1130c432d2c66d2ecbe240f1257800.pdf
Optimal Water Scheduling in Irrigation Networks Using Genetic Algorithm
M.J
Monem
Associate Professor, Dept. of Hydraulic Structures, Faculty of Agriculture, The University of Tarbiat Modares, Tehran, Iran.
author
M.R
Najafi
Assistant Professor, Dept. of Irrigation and Reclamation Engineering, Faculty of Soil and water Engineering, Campus of Agriculture and Natural Resources, Tehran University, Karaj, Iran
author
S
Khoshnavaz
Former Graduated Student, Dept. of Irrigation and Reclamation Engineering, Faculty of Soil and water Engineering, Campus of Agriculture and Natural Resources, Tehran University, Iran.
author
text
article
2007
per
The development of water delivery schedules in irrigation canals is mostly performed on the basis of hueristic methods and personal judgment. However, the great impact of water delivery schedules on the performance of systems has recently called for analytical methods to be considered. Analythical methods used so far are mostly single objective. Only one study has considered a multi-objective approach using simulated annealing optimization techniques. In this research the genetic algorithm is used and a model has been developed accordingly. In this model an optimal water delivery schedule for lateral intakes is developed such that different objectives of canal capacity and/or delivery periods are optimized. In this model the number of lateral intakes, their delivery flow limits, and coverage areas are given and a optimal water delivery schedule for the distributary canal is determined. The model is applied on one of the secondary canals of Fomanat Irrigation Network in west Gilan Province, Iran. For this purpose, two objective functions and two options for irrigation blocks including 6 and 7 groups of lateral intakes, totally 4 variants, are tested. The model has derived the optimal water delivery schedule for each variant. Considering the management strategies, the best option could be selected.The results show the ability of the developed model as an efficient tool for water management in irrigation canals.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
1
11
https://www.iwrr.ir/article_15465_feb9e9710d4b8d468caa6f03d7b0501b.pdf
Significance Level in the ENSO- based Prediction of Autumnal Dryness and Wetness in Iran
M. J
Nazemosadat
Associate Professor, College of Agriculture, Shiraz University
author
A
Ansaribasir
MS, College of Agriculture ,Shiraz Univercity
author
M. R
Pishvaei
Assistant Professor, College of Agriculture, Shiraz University
author
text
article
2007
per
Reliable prediction of dry and wet periods is an essential component in competent management of water resources. A more reliable prediction of the climate, pushes the public approach to these predictions further and lowers the disaster costs. Since the (ENSO)1 has recently been introduced as an important predictor for the anticipation of seasonal wet and dry conditions in Iran, the present study evaluates the significance level of such prediction for autumal and six-monthly (October- march) precipitation using Fisher2 Exact test. Using the summer time (SOI)3 as the predictor, the significance of the occurrence of meteorological dry and wet conditions during following autumn is investigated. It has been shown that after a strong El Niñoevent in summer (SOI<-5), wet conditions are anticipated for most parts of the country at a 95% significance level. On the other hand, the prediction of dry conditions is not significant for such an event. It has found that the occurrence of normal rather than wet or dry conditions is significant for the eastern coasts of the Caspian Sea as the El Niño is prevalence. During strong vigorous cold ENSO periods (SOI >5), the occurrence of autumnal dry conditions are significant for most of the studied stations at the 95% level. During such periods the prediction of wet conditions were found to be statistically meaningless for all parts of the country. It is shown that the occurrence of summer El Niño leads to the dominance of wet conditions in about half of the studied stations. The prevalence of summer La Nina does not however lead to the wide spread six-monthly drought.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
12
24
https://www.iwrr.ir/article_15466_f9adfa42585c63d6ce5f84284d45f0f1.pdf
Investigation of Meteorological Droughts in the Sistan and Balouchestan Province, Using the Standardized Precipitation Index and Markov Chain Model
T
Raziei
Research Climatologist, Soil Conservation and Watershed Management Research Institute (SCWMRI), Tehran, Iran and Ph.D Candidate in Climatology, University of Tehran, Tehran, Iran-
author
P
Daneshkar Arasteh
Assistant Professor, International University of Imam Khomeini, Qazvin, Iran
author
R
Akhtari
Research Assistant, Soil Conservation and Watershed Management Research Institute (SCWMRI)
author
B
Saghafian
Research Associate, Soil Conservation and Watershed Management Research Institute (SCWMRI), Tehran, Iran
author
text
article
2007
per
Drought is an insidious environmental phenomenon which is more pronounced in arid and semi arid regions. Central, eastern, and southern regions of Iran are characterized as arid and semi arid climate. Precipitation variability in the Sistan and BalouchestanProvince is very high. This is due to remoteness from Mediterranean cyclonic trajectory and the predominance of a subtropical high pressure system. Accordingly, the Sistan and Balouchestan is more prone to drought than other provinces in Iran. In this paper, the probability of drought occurrence and extent in this province is investigated applying lag-1 Markov chain on SPI time series in 3- and 6-month time scales. The results showed that the probability of drought persistence, based on 6-month SPI time series, is higher than 70 percent in central portion of the province and decreases to 50 percent moving east. Considering the drought equilibrium probability, the results also indicated that the central district of the province are affected by drought events 30% of the time and therefore is more vulnerable to drought conditions compared to other regions in the province.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
25
35
https://www.iwrr.ir/article_15467_aa2b7748b30f06f4b0277b2870be94d7.pdf
Evaluation of Runoff Stochastic Models in Different Spatial and Temporal Scales
Case Study: Basins of Southwestern Iran
M. R
Ghanbarpour
Assistant Professor, Faculty of Natural Resources, University of Mazandaran, Sari.
author
text
article
2007
per
Like many other hydro-climatological data, runoff has seasonal variability incorporated with random processes. Previous research has shown that stochastic models are the most suitable simulation tool for random variables with seasonal variability. In this study, a time series analysis approach was utilized to obtain monthly, bimonthly, and seasonal runoff stochastic models in a few sub-basins in Dez and KarunBasin, in southwestern Iran. These sub-basins vary widely in area (from 37 to 9900 square kilometers) in order to study the models with respect to the different spatial scale. The results have shown that the kind of stochastic model in longer temporal scales is not correlated with the area of the basin. Therefore, this result could be generalized to other similar basins. On the other hand, the Monthly Autoregressive Integrated Moving Average model has different patterns regarding the spatial scale of the basin. It is shown that the autoregressive order of small basins could be greater than one. Extracted stochastic models in this research can be used for runoff forecasting in future studies and research.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
36
44
https://www.iwrr.ir/article_15476_d27d1e67edc2fc8c03ecf94e31e5a435.pdf
Experimental Investigations and Development of New Relations to Determine Run-down Levels of Irregular Waves on Reshaping Breakwaters
N
Shirian
Phd.Candidate, Tarbiat Modares University, Tehran, Iran
author
M
Shafieefar
Assistant Professor, Tarbiat Modares University, Tehran, Iran.
author
P
Aghtouman
Faculty Members of Soil Conversation and Watershed Management Research Center
author
V
Chegini
National Oceanographic Center
author
text
article
2007
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In this research, the effects of irregular wave action on run-down on the slope of reshaping rubble–mound breakwaters have been investigated. Reshaping breakwater is a new kind of breakwater in which the initial profile is changed to an S-shaped profile, once affected by waves. Therefore, the relations related to run-down levels on conventional breakwaters cannot be used for this type of structure. This research is conducted based on Experimental Modeling. Experiments were performed in the Soil Conservation and Watershed Management Research Institute (SCWMRI) for multiple cross sections of reshaping breakwaters with three different slopes in years 2003 and 2004. The wave flume was equipped with a modern DHI wave generation system, which contains paddle, power pack, hardware and software divisions. The hydraulic responses mentioned above, were investigated by changing the wave parameters such as significant wave height, mean and peak wave period and storm duration on the three structure’s seaward slopes, equal to 1:1.25, 1:2.0, 1:2.5. JONSWAP wave spectrum was used in all experiments. The Armored layer materials were included in three grading classes (Dn85A/Dn15A=1.14, 1.44, 1.82) and a Range of structural index permeability, Pe. In order to investigate the effects of changing structural geometry, wave properties, and the comparison between two scales, 120 tests were performed with 1000 to 6000 waves. Finally the results of different scale factors were compared. The experimental results were plotted as graphs showing the run-down levels versus the surf similarity parameter and deepwater wave steepness. Because the Iribarren number does not accurately describe the combined effects of slope and wave steepness, an improved and new formula was fitted to data using multiple linear regression and nonlinear regression, which results in some new empirical equations presented in this paper.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
45
55
https://www.iwrr.ir/article_15477_52fb5e77277bb88529e6b0dd2f7320a5.pdf
Head Velocity and Entrainment of Density Current in an Expansion Reach
H
Torabi Poudeh
Ph.D. Student, School of Water Sciences and Engineering, Shahid Chamran, University, Ahwaz, Iran
author
M
Fathi Moghadam
Assistant Professor, School of Water Sciences and Engineering, Shahid Chamran, University, Ahwaz, Iran
author
M
Ghomeshi
Assistant Professor, School of Water Sciences and Engineering, Shahid Chamran, University, Ahwaz, Iran
author
M
Shafai-Bajestan
Professor, School of Water Sciences and Engineering, Shahid Chamran, University, Ahwaz, Iran
author
text
article
2007
per
Velocity and Entrainment of density current in the expansion reach where a river enters into a dam reservoir, a lake, or open sea is of utmost importance. The present study investigates the head velocity and entrainment of density currents in an Expansion Reach. The effects of discharge and bed slope on the head velocity and entrainment of the density current were evaluated by a physical and 3D mathematical model. Experiments were conducted in a flume, 6.0 meters long, 0.72 meters wide, and 0.6 meters in height. Head velocity was measured for an expansion degree of 8 in slopes of 0.0009 and 0.0016 for various discharges. Important parameters were normalized and a two-dimensional laser Doupler was used to develop the flow body velocity profile. The measurements showed that mixing values were higher in a divergent cross-section compared to a fixed cross-section. During some experiments a hydraulic jump was also detected depending upon the levels of the density current and slope of the bed in the divergent cross-section, which was investigated and the results are presented accordingly.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
56
67
https://www.iwrr.ir/article_15478_d412e337a5b9d3c9c27f47ac64a80c49.pdf
The Investigation and Evaluation of the Pressure Flushing Through Storage Reservoirs Using Physical Models
S
Emamgholizadeh
Assistant Professor of Shahrood University
author
M
Bina
Assistant Professor of Shahid Chamran University
author
M
Ghomeshi
Assistant Professor of Shahid Chamran University
author
H
Jahani
Engineer Khuzestan Water and Power Authority (KWPA)
author
text
article
2007
per
Sedimentation in reservoirs is one of the most serious problems of most dams. Sustainable reservoir management necessitates the deposited sediment most be removed to reduce the inactive storage of the reservoir. Different methods can be used accordingly to control sedimentation and maintenance of the dam reservoir. Dredging, sluicing, and flushing are among these methods. In flushing methods, the previously deposited sediment would be flushed from the reservoir by opening the bottom outlets. In the pressure flushing method, the amount of the flushed sediments depends on many parameters such as the water depth over the bottom outlets, the discharge through bottom outlets, the size of the outlets, the geometry of the reservoir, and the size and type of the sediments.
In this study laboratory experiments were performed to investigate the flushing processes during pressure flushing. The effects of the discharge through bottom outlets and the water depth over the bottom outlets were investigated using 3 sizing of non-cohesive sediments (fine, medium, and coarse sediments). The physical model was constructed in the Hydraulic Laboratory at the Water and Science Collage of the University of Shahid Chamran, Ahwaz, Iran. The results indicated that the amount of sediment flushed increases as the depth of water in reservoir decreases and the discharge from outlets increases. Under the same conditions the flushed sediment volume is increased moving from coarse sediments to fine sediments.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
68
79
https://www.iwrr.ir/article_15498_f8ac06a4444ea6a86ba4aa27a4de8805.pdf
Flood Control in Urban Basins Using Detention Ponds Comparison to Localized River Engineering Countermeasures
A.R
Shokoohi
Assistant Professor of Imam Khomeini International University, Ghazvin, Iran.
author
Sh
Daneshvar
Water Resources Engineer, River Engineering sec., Mahab Ghods Consulting Engineers, Tehran, Iran.
author
text
article
2007
per
In this paper effects of constructing detention ponds for flood control in basins immediately upstream an urban area, are studied. Comparisons are made between this practice and conventional localized river engineering countermeasures regarding socio-economical aspects. The study is conducted in Abkharvar urban basin in Behbahan city in the KhouzestanProvince, in southwestern Iran. Based on the design flood routing, the effects of detention ponds on the dimensions of the conveyance canal are studied. Total costs of flood control alternatives are then compared. Results show that regarding socio-economical issues, detention ponds are superior to conventional localized river engineering and flood control countermeasures for flood control purposes in urban basins.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
80
83
https://www.iwrr.ir/article_15499_d725130f85a97dd388c6730f4cc2ca19.pdf
Role of Drops on Inundation Depth and Area Variations in a Stretch of the Kan River
S.H.R
Sadeghi
Respectivelye Professor, Dept. of Watershed Management Engineering, College of Natural Resources and Marine Sciences, Tarbiat Modares Univ., Noor46414-356, Mazandaran, Iran
author
M
HajiGholizadeh
RespectivelyFormer Master Student and Lecturer Management College of Natural Resources and Marine Sciences, Tarbiat Modares Univ., Noor46414-356, Mazandaran, Iran
author
H
Motieei
Respectively Student and Lecturer, Dept. of Watershed Management Engineering, College of Natural Resources and Marine Sciences, Tarbiat Modares Univ., Noor46414-356, Mazandaran,
author
H
Motieei
Assistant Professor, Water and Power Industry University, Tehran, Iran
author
text
article
2007
per
Studying the role of drops as one of the important hydraulic structures for flood control is essential. In the present study, the effects of drops on inundation depth and extension have been investigated in a reach of the Kan River with 7 Km in length. The hydraulic characteristics of flow were computed for floods with 5 to 700 year return periods using the HEC-RAS computer model for both upstream and downstream sections of the structures. The results of this study verified a different role of drops as well as an incremental and reductive impact on inundation depth and extension in upstream and downstream, respectively.
Iran-Water Resources Research
Iranian Water Resources Association
1735-2347
3
v.
1
no.
2007
84
87
https://www.iwrr.ir/article_15500_fe31a879f3399be991fd5120527cd4e5.pdf