ORIGINAL_ARTICLE
A study of head velocity variations for density currents with discharge and slope variations in a divergent cross sections
Studying the head velocity of density currents in reservoirs and seas is very important. One critical parameter largely affecting the head velocity of density currents is the variations of a river section in dams'' reservoirs. In the present study, using a physical model and a 3 dimensional mathematical model the head velocity of a density current into a divergent reservoir is investigated by various discharges and slopes. The experiments were performed in a flume with width of 72.5 m, length of 6 m and height of 60 cm. Different slopes and discharges are used. Then the Mathematical model was calibrated for a determinate discharge rate and the results were verified for a wide range of discharge rates.The mathematical model was performed for a wide range of density current discharges and the results of both models were analyzed. At the end, head velocity variations for density currents due to the slope and discharge variations were presented in form of dimensionless parameters for fixed and divergent cross- sections
https://jise.scu.ac.ir/article_13378_fc7dd897ea71cc59bf3787e5a04a92b4.pdf
2009-06-22
1
14
10.22055/jise.2010.13378
Density currents
Head velocity
Reservoir
Richardson number
Hassan
Torabi Poodeh
torabi1976@gmail.com
1
Ph.D. Student, School of water Sciences Engineering Shahid Chamran University of Ahwaz, Iran
LEAD_AUTHOR
Mehdi
Ghomeshi
m.ghomeshi@yahoo.com
2
Professor of water Sciences Engineering Shahid Chamran University of Ahwaz, Iran
AUTHOR
Manoochehr
Fathi Moghadam
fathi49@gmail.com
3
Associate Professor of water Sciences Engineering Shahid Chamran University of Ahwaz, Iran
AUTHOR
ORIGINAL_ARTICLE
The clogging of some available emitters in Iran when using saline water
Emitter clogging is a serious problem in trickle irrigation systems, which can increase Operating costs, water application rate, water distribution uniformity and farmer’s confidence in the system can be affected. Also in different regions of country such as Kerman province large amount of groudwater is saline and brackish and recently, due to extra extraction, the water quality is decreasing speedly.
The experiment was conducted in Kerman province for 9 months between 2003-4 years on a land 8 × 25 m which consisted of 5 rows of 20 m. Each row had 50 emitters and water electrical conductivity (EC) was 8 dS/m. In this study, the relative resistance of different type of emitters (Inline, Microflapper, Online, Turbo, and tape) to clogging was evaluated when using saline irrigation water. Emitter mean discharge, emission uniformity (EU), Christiansen coefficient of uniformity (CU), and manufacturer’s coefficient of variation of emitters (Cv) were calculated during the experiment. According to findings: The clogging was 2% for Inline and Microflapper emitters but Online, Turbo and Tape emitters had 10%, 18% and 68% clogging respectively. The clogging of emitters and their discharge dispersion caused a decrease in emitter mean discharge, EU, CU and an increase in Cv during the experiment. The relative comparison of emitters showed that Online, Turbo and Tape emitters were significantly affected by saline water, so, they can not be suggested for irrigating with salin water. Therefore, Microflapper and Inline emitters along with good management were suggested when facing on saline irrigation water.
https://jise.scu.ac.ir/article_13379_d7a8e6e99db668fa972d300dde20b01c.pdf
2009-06-22
17
25
10.22055/jise.2010.13379
Emitter
Saline water
Clogging
Emission uniformity
Masoud
Farzam Nia
esf1380@yahoo.com
1
Senior Researcher, Agricultural Research Institude of Kerman, Iran
LEAD_AUTHOR
Seyed Abolghasem
Haghayeghi Moghadam
2
Senior Researcher, Agricultural Research Institude of Khorasan Razavi Iran
AUTHOR
ORIGINAL_ARTICLE
Characteristics of Hamedan province during period 1975-2005
In this research, the annual air temperature parameters that observed at five meteorological stations situated in the Hamedan region are analyzed to determine the temporal pattern of long-term trends of data and the probable climate change, during the period from 1975 to 2005. In this regard, the mean, maximum and minimum series of annual and temperatures are investigated based on the Mann-Kendall and NRMC methods. The results show that the maximum temperature variations at all the stations have the smooth positive significant trends, (except those to Nojeh and Darghazin stations which don’t have any trends). In the case of the minimum temperature, in exception to Varayaneh (where present a decreasing trend), the other stations have the rapid significant increasing trends. The mean annual temperatures at all of stations also show the significant rapid increasing trends (except those to Varayaneh and Darghazin stations). The NRMC method, that divide data on two equal divisions, (base on a normal year identification that in this study is 1990), show the similar results same as the Mann-Kendall test. This study not only illustrates the similar results of the two different tests on climate change identification but also indicate a significant warming at the majority stations in region (especially in the central area). These results could be used for mapping and forecasting of future droughts as well as water managements.
https://jise.scu.ac.ir/article_13386_cab8dedc6b8731ec54108264dbbd84c7.pdf
2009-06-22
27
41
10.22055/jise.2010.13386
Hamadan
Air temperature
Mann-Kendall
NRMC test
climate change
Safar
Marofi
marofisafar59@gmail.com
1
Associate Professor, Department of Irrigation, Faculty of Agriculture, Bu-Ali Sina University, Hamadan, Iran.
LEAD_AUTHOR
Zohreh
Marianji
z.maryanaji@gmail.com
2
Instructor, Meteorological Research Center, Hamadan, Iran
AUTHOR
Parisa
Hossian Zadeh Tallaeei
3
Msc. Student, Department of Irrigation, Faculty of Agriculture, Bu-Ali Sina University, Hamadan, Iran
AUTHOR
ORIGINAL_ARTICLE
Investigation on the effects of the sprinkle irrigation time on the yield of cotton and its components
Sprinkler irrigation is one of the irrigation systems used for cotton. In this research study an extensive experiment was carried out on cotton in split plot form with four treatments and three replications during the years 2004 and 2005 in the Gorgan Agricultural Research centre. The amount of irrigation was set to be equal to 70% of the evaporation of the class A evaporation pan. In order to evaluate the effect of irrigation time on yield and its components four irrigation treatments were considered including: T1(06:00 to 9:00 ), T2 (09:00 to 13:00), T3 (14:00 to 20:00) and T4 (20:00 to 05:00). Comparison of the average value of results showed that the yield for the T4 treatment was superior. The same results were also obtained for the weight of cotton-pod, plant height and the number of branches. Although there was not any meaningful differences between the years 2004 and 2005, but the minimum yield was measured for the T3 treatment. It was not found any significant difference on the cotton pre-maturity for all treatments. In order to increase the cotton yield it is proffered to manage sprinkle irrigation time for morning or night.
https://jise.scu.ac.ir/article_13387_36c02e4b5f4be1160dc2a1083035162b.pdf
2009-06-22
43
48
10.22055/jise.2010.13387
Sprinkle irrigation
Cotton
shedding
Saeed
Boroomand-Nasab
boroomandsaeed@yahoo.com
1
Shahid Chamran University of Ahwaz, Faculty of Water Sciences Engineering
LEAD_AUTHOR
Seyed Mahmmod
kashefipour
kashefipour@excite.com
2
Associate Professor, Shahid Chamran University of Ahwaz, Iran
AUTHOR
Parhan
Sohrabi Moshk Abadi
sohrabi47@yahoo.com
3
Cotton Research Center, Gorgan, Iran.
AUTHOR
ORIGINAL_ARTICLE
The study of effect of alternate furrow irrigation on quality and quantity CP69-1062 variety of sugarcane at different stages of growth
Sugarcane is one of the important crops in Khuzestan provience which consumes large amount of water, specialy in the warm season. In this study in order to optimize water consumption in a high efficiency, five treatments with three replications using randomized complete block design were applied in Karun Agro Industry, Inc The first treatment was contained of conventional irrigation method which was used in the area (untreated as an example of witness). The second treatment was alternate furrow irrigation method during the growth season. The treatments third, forth and fifth were irrigated by alternate furrow irrigation method in the portion of the growing season and then shifted to the conventional irrigation method for the remaining of the growing season. These treatments were sequentially included with the alternate furrow irrigation method, at the beginning of the growing season, during the mid-stage growing season and finally at the late stage of growing season. The results indicated that there were no significant differences between all treatments, but the third treatment showed an increased of 8.02 tons/ha of sugarcane and 2.08 tons/ha sugar more than the conventional irrigation method. With the view of percent of recovery sugar, sequentially treatments fourth, fifth, and third have showed about 5% in surface area in better performance in comparison with the conventional method. The results also, indicated that water use efficiencies of treatments second and first were 0.51 kg/m3 and 0.38 kg/m3 respectively. Therefore, it can be concluded that the alternate furrow irrigation system in general can cause an increase in cane yield and water productivity.
https://jise.scu.ac.ir/article_13388_0bbd81cde9a12dcfb567fdb05305f26e.pdf
2009-06-22
49
56
10.22055/jise.2010.13388
Sugarcane
Deficit İrrigation
alternate furrow irrigation
Water use efficiency
Mansoor
Noori
1
Senior researcher, Karun Agro-industry Inc., Ahwaz, Iran
AUTHOR
Saeed
Boroomand-Nasab
boroomandsaeed@yahoo.com
2
Shahid Chamran University of Ahwaz, Faculty of Water Sciences Engineering
LEAD_AUTHOR
ORIGINAL_ARTICLE
Assessment of the relations between the surface meteorological parameter changes and the spring rainfall of Khorasan-e Razavi province
تغییرات اقلیمی جهان و چرخه عمومی جو تحت تاثیر پدیده های بزرگ مقیاسی است که درسطح آب های آزاد جهان اتفاق می افتد. بسیاری از این پدیده ها که به سیگنال های بزرگ مقیاس اقلیمی معروفند ، از بیش از یک قرن پیش شناخته شده بودند. سیگنال های مزبور معمولاً با استفاده از شاخص هایی نظیر فشار و دمای سطح آب اقیانوس ها و غیره محاسبه می شوند. به منظور بررسی ارتباط تغییرات پارامترهای هواشناسی سطح زمین نظیر آب قابل بارش، باد مداری و باد نصف النهاری با بارش، استان خراسان رضوی انتخاب شد. پس از بررسی های لازم و تکمیل خلاهای آماری ، تعداد 38 ایستگاه همدیدی، اقلیم شناسی و باران سنجی تحت پوشش سازمان هواشناسی کشور و وزارت نیرو، انتخاب شد. در مرحله بعد، در محیط نرم افزار Arc GIS ، سری زمانی بارش متوسط منطقه ای به روش کریجینگ محاسبه شد. با استفاده از روابط همبستگی به دست آمده بین بارش متوسط منطقه ای و سیگنال های هواشناسی شاخص در بازه های زمانی مختلف، ارتباط این پارامترها با بارش متوسط منطقه ای استان خراسان رضوی مشخص شد. نتایج نشان دهنده ارتباط معنی دار این پارامتر ها با بارش استان خراسان رضوی می باشد و می توان از این پارامترها در تشخیص دوره های خشک و تر در منطقه مورد مطالعه استفاده کرد.
https://jise.scu.ac.ir/article_13389_9167a778ed3677eb3f1ad6622e0d7f67.pdf
2009-06-22
57
74
10.22055/jise.2010.13389
Gholam Abbass
Falah Ghalhari
1
Department of Physical geography, University of Isfahan and Researcher of Climatological Research Institute (CRI), Mashad, Iran
LEAD_AUTHOR
Javad
Khoshhal
2
Department of physical Geography, University of Isfahan, Iran
AUTHOR
Hassan
Salehi
3
M. Sc. student in Agro-Meteorology, Ferdowsi University of Mashhad, Iran
AUTHOR
Majid
Habibi No Khandan
habibi3558@gmail.com
4
Researcher Fellow Climatological Research Institute (CRI), Mashhad, Iran
AUTHOR
ORIGINAL_ARTICLE
Investigation of design criteria for Maron hydropower tunnels of ehbahan
The principle of economically optimal design of water conveyance and water supply systems has been one of the major concerns of researchers and designers for along time. In order to design a hydropower plant many combinations of headrace tunnel, penstockand surge tank sizes may be selected.The designalternative that has a maximum benefit-cost ratio is the one which must be sought. be selected that has the maximum benefit-cost ratio. In this paper, unsteady flow analysis is performed initially to get maximum pressures in headrace tunnel and penstocks and maximum water elevation in surge tanks. Based on these results structural design of headrace tunnel, penstocks and surge tanks is done. Total cost of the project is then calculated. Having calculated the head at turbines, sales of power and revenues are determined to get the benefit-cost ratio. It is obvious that for every selected size of involved structures, hydraulic and optimization analyses should be done. The genetic algorithm optimization technique is utilized for optimal design of headrace tunnel, penstocks, and surge tanks. The benefit-cost ratio is considered to be the objective function in the optimization analysis. The hydraulic and optimization analyses have been linked in an iterative procedure to develop a general model for optimal design of hydropower plant projects. The accuracy and convergence of the developed model have been quite satisfactory.
https://jise.scu.ac.ir/article_13390_d41d8cd98f00b204e9800998ecf8427e.pdf
2009-06-22
75
85
10.22055/jise.2010.13390
hydropower
headrace tunnel
penstock
surge tank
Sadegh
Haghighipour
haghighipour_eng@yahoo.com
1
Institute for higher education ACECR, Ahwaz, Khoozestan
LEAD_AUTHOR
Jamal
Mohammad Vali Samani
samani_j@modares.ac.ir
2
Associate Professor, Hydraulic Structures Department, Tarbiat Modares University of Tehran, Iran
AUTHOR
ORIGINAL_ARTICLE
Investigation of different local bottom roughness arrangements on transverse mixing coefficient in an open rectangular flume
Transverse mixing coefficient is one of the hydraulic parameters of flow by which the amount of self-refinement and dilatation of rivers can be estimated. In this research, the effect of different roughness arrangements on transverse mixing coefficient has been studied. Experimental studies were carried out in a rectangular straight open channel with 7m length and 0.32m width and 0.35m height. Water was circulated in the flume with the rate of 16.4 lit/s. The flow was uniform and the depth of water was 11.4 cm which was controlled with a gate way. Tracer was continuously injected with a constant head in to the open channel flow at the center of the flume. The dye concentrations at 4 different downstream distances from the injection point in 27 points were measured and dimensionless transverse mixing coefficient has been determined for different block arrangements. The results show that the block arrangement with three row of increasing height from 1.5 cm to 3 cm in the flow direction gives the best efficiency.
https://jise.scu.ac.ir/article_13391_27a3d4497d95aa979aee30a70edca88f.pdf
2009-06-22
86
97
10.22055/jise.2010.13391
transverse mixing coefficient
Pollution
Local roughness
complete mixing length
Aliyeh
Saadat Pour
1
Graduate Student, Isfahan University of Technology, Esfahan, Iran
AUTHOR
Manoochehr
Heidar Pour
heidar@cc.iut.ac.ir
2
Associate Professor, Isfahan University of Technology, Esfahan, Iran
LEAD_AUTHOR