Islamic Azad University, Ahvaz Branch
Journal of Water Science & Engineering
2251-6905
4
10
2014
10
01
Assessment of reservoir sedimentation by mathematical model GSTARS3 on Masjed Soleyman dam in Khuzestan Province-Iran
7
18
EN
Reza
Tajmehr
Houshang
Hasounizadeh
Samaneh
Abdeveis
abdovissamaneh@gmail.cim
Accumulation of sediment transport volume and reduce the useful life of dams, water storage tanks can be. So far, many methods for calculating sediment this is presented in reservoirs are generally classified into two categories: mathematical modeling and experimental .This study examines the effect of using Gstars model parameters in the model, deposition of sediment in the reservoir tank and forecasting of Masjed Soleiman was made. Results indicated that the most sensitive parameter model of deposition and sediment transport equations show that. The model is calibrated using data from the second flood A is less critical than the daily statistics Negligible error rate of 2% between the observed value and the calculation results show that Gstars mathematical model for use in estimating the amount and distribution of precipitation with a suitable model. The annual volume of tank 1/6 was estimated that the observation of the 1/1 percent.
http://wsej.iauahvaz.ac.ir/article_531134.html
http://wsej.iauahvaz.ac.ir/article_531134_9aec68b82ffb751ccc6e4535c4ea1a2a.pdf
Islamic Azad University, Ahvaz Branch
Journal of Water Science & Engineering
2251-6905
4
10
2014
10
01
Evaluation of monitoring network density using discrete entropy theory
19
36
EN
Somaye
Khalifeh
Water Resources Engineering, Water Engineering Department, ShahidBahonar
University of Kerman, Kerman,Iran.
s.kh.arshad@gmail.com
The regional evaluation of monitoring stations for water resources can be of great importance due to its role in finding appropriate locations for stations, the maximum gathering of useful information and preventing the accumulation of unnecessary information and ultimately reducing the cost of data collection. Based on the theory of discrete entropy, this study analyzes the density of rain gage stations in Zohreh Basin located in Fars Province, Iran. Considering the marginal entropy index H(x), joint entropy H(x, y), information send index S(i) and received index R(i) of each station and information transfer index (ITI) between stations, important stations and weak areas of information transfer have been determined in the monitoring network of the basin and spatial interpolation has been calculated. The results showed that the density of the rain gage monitoring network is acceptable. The calculated values for the indexes of R(i) and S(i) are completely parallel and each station receives almost the same amount of data that it sends to other stations. Finally, two new indexes of NH (x) and NH (xˆ(i)) produce equivalent results with R(i) and S(i) indexes. The obtained results showed that 3 stations Noorabad, Baraghan and Ghoshneghan are in the crisis condition and had been and replace it there. also due to the nature of the statistical method, removing of mention station without cheking hydrological conditions and how of hydrograph combination is recommended.
http://wsej.iauahvaz.ac.ir/article_531135.html
http://wsej.iauahvaz.ac.ir/article_531135_963c24f2c3bdb573133f15d166b03e7b.pdf
Islamic Azad University, Ahvaz Branch
Journal of Water Science & Engineering
2251-6905
4
10
2014
10
01
Evaluate changes in wind wave height at different return periods and statistical distribution
37
50
EN
Reza
Nayebi
Morteza
Bakhtiari
دانشگاه علوم و فنون دریایی خرمشهر
mortezabakhtiari@yahoo.com
Masoud
Sadri Nasab
Nima
Shahni Karam Zadeh
Waves are main characteristics of seas that produce by wind. Importance of the study of waves and recognizing the wave climate in the coastal zone management that the waves are the most important influence on the design and implementation of all projects. Wave are main boundary condition in dynamic loading and structural calculations and hydraulic coastal structures. Height of waves are the most important wave parameters can be affected by various factors change. In present study evaluate changes of this parameters in return periods 2, 5,10,25,50 and 100 years based on statically distribution and bed roughness coefficient. In order to study use mike21 study. The result showed that bed roughness has important significant effects on the reduction or increase of the wave’s height. The analysis was performed according to the return period for the design show that 50 and 100 years. In this return periods have different prior and subsequent periods have been even more. The results also show coefficients of each wave changes substrate design 2-year-old to 200 years old in about 7 to 10 cm.
http://wsej.iauahvaz.ac.ir/article_531136.html
http://wsej.iauahvaz.ac.ir/article_531136_c99abf63736d3f67e963d91daf55d990.pdf
Islamic Azad University, Ahvaz Branch
Journal of Water Science & Engineering
2251-6905
4
10
2014
10
01
Estimating IDF based on daily precipitation using temporal scale model
51
61
EN
Razi
Khalaf
razikhalaf57@gmail.com
Saeed
Soltani Koupai
<strong>The intensity –duration –frequency (IDF) curves play most important role in watershed management, flood control and hydraulic design of structures. Conventional method for calculating the IDF curves needs hourly rainfall data in different durations which is not extensively available in many regions. Instead 24-hour precipitation statistics were measured in most rain-gauge stations. In this study, scaling properties of extreme rainfall are examined to derive scaling IDF curves over different durations. This new method in comparison with traditional method is less computational steps and has lower parameters numbers which causes increasing in reliability of IDF curves. Scaling method was used to extract the IDF curves in Ahwaz rain-gauge station and results proved the efficiency and robustness of the scaling method. The accuracy of scale model method for Determining precipitation intensity, with Duration 30 to 180 minuts in Ahwaz station, is quite acceptable and maximum error is about 11.5%. </strong>
http://wsej.iauahvaz.ac.ir/article_531137.html
http://wsej.iauahvaz.ac.ir/article_531137_5ef215ded73d5c2b989915460a80eac9.pdf
Islamic Azad University, Ahvaz Branch
Journal of Water Science & Engineering
2251-6905
4
10
2014
10
01
Evaluating the Methods of Estimating Potential Evapotranspiration in Omidiyeh Town
63
74
EN
Ali
Assareh
a.asareh@iauahvaz.ic.ir
Hadis
Davoodi
In order to determine the required water for irrigation it is necessary to calculate the amount of needed water by plant or evapotranspiration. The equations that are used to calculate evapotranspiration are not applying the same climatic parameters and, due to their experimental nature, they are not suitable for all climatic conditions. In the present study in order to compare evapotranspiration methods and to determine the best method to estimate potential evapotranspiration in Omidiyeh Town, the FAO - Penman - Monteith (FP-M) method was considered as the reference and accuracy of Blaney Criddle (BC), Torrent White (TW) and Hargreaves - Samani (HS) methods that need fewer climatic parameters was compared to it. In addition, statistical data of synoptic station in Omidiyeh were used for the period of 2006 to 2015. The results showed that Blaney - Criddle method, compared to other methods used, with the highest correlation coefficient and the lowest standard error along with FAO Penman-Monteith method were more accurate in estimating potential evapotranspiration in Omidiyeh. Moreover, Blaney Criddle has estimated the average potential evapotranspiration of the town 22% less than the reference method and has the lowest difference to the reference method.
http://wsej.iauahvaz.ac.ir/article_531138.html
http://wsej.iauahvaz.ac.ir/article_531138_b5878310db8304c01953f259a1061450.pdf
Islamic Azad University, Ahvaz Branch
Journal of Water Science & Engineering
2251-6905
4
10
2014
10
01
Climate change Effects of Surface soil temperature profile in Ahwaz
75
85
EN
Kazem
Hemmadi
fatemeh
zakerhosseini
zakerfatemeh@gmail.com
In arid and semi-arid regions, soil surface warming is a considerable phenomenon causing a high thermal gradient which makes water flow intensely. The degree of soil temperature is effective on crop production, plant growth and soil microorganisms. In recent years, the ascending trend of temperature has been substantially noticed by researchers in the issues of pointwise climate change and at watershed level. The present study proved the occurrence of ascending trend in time series of temperature through both non-parametric and Mann Kendall parametric tests as well as linear regression in synoptic station in Ahwaz province, Iran. Next, meanwhile the degree of trend was determined, the relations of SoilMedium temperature were obtained for the depths of 5 and 30 cm. Applying the relations of air temperature ascending trend together with the relations of soil-medium temperature both developed a new relation which can express the ascending tend of soil temperature based on medium temperature. These relations indicated that, in depths of 5 and 30 cm, the soil temperature is higher respectively by 2 and 1 ˚C than medium temperature. Furthermore, the ascending trend of temperature gradient of soil surface profile in depths of 5 and 30 cm is respectively 0.038 and 0.030 ˚C per year. Although the increase of soil temperature is assumed to be limited, these low soil temperature changes are effective on plant growth and soil properties like moisture profile of soil structure alteration, thermal conductivity, heat capacity and heat diffusion coefficient.
http://wsej.iauahvaz.ac.ir/article_531139.html
http://wsej.iauahvaz.ac.ir/article_531139_ba32a3991ce1bcba20afc37ce2977419.pdf