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Showing 6 results for Babazadeh
Improving Soybean Water Use Efficiency Using Partial Root Drying
M Sarai Tabrizi, H Babazadeh, M Parsinejad, S.a.m Modares Sanavi,
Volume 14, Issue 52 (sumer 2010)
Abstract
Deficit irrigation is one of the irrigation management methods that is used to increase Water Use Efficiency. Considering the internal plant adaptability characteristic to water shortage, Partial Root Drying method has been introduced in recent years. In this field research improvement of Water Use Efficiency for Soybean was determined. This experiment which was conducted at four furrow irrigation treatments at the Research Field of Tehran University in Karaj in 2008, consists of full irrigation (100% soil moisture deficit compensation), conventional deficit irrigation at 50 and 75 percent soil moisture deficit compensation and Partial Root Drying at 50 percent soil moisture deficit compensation with three replications. The amounts of irrigation used were exactly compensation level (negligible loss). Results indicated that Water Use Efficiency according to Duncan's Multiple Range Test at the five percent level of probability there was a significant difference between partial root drying treatment (PRD50%) and conventional deficit irrigation treatment at fifty percent soil moisture deficit compensation (DI50%),. Water Use Efficiency in PRD50% compared with DI50%, DI75% and full irrigation increased by 48.3%, 61.9% and 70.1% respectively.
Modeling Basil (Ocimum basilicum L.) Response to Simultaneous Salinity and Nitrogen Deficit Stresses
M. Sarai Tabrizi, M. Homaee, H. Babazadeh, F. Kaveh , M. Parsinejad,
Volume 19, Issue 73 (fall 2015)
Abstract

Salinity and nutrient deficiency particularly nitrogen are two important limiting factors for yield production in arid and semi-arid regions. The objective of this study was to model basil response to combined salinity and nitrogen deficiency. To that end, modified Leibig-Sprengel (LS) and modified Mitcherlich-Baule (MB) and also some newly derived models based on combination of MB with salinity models of Maas and Hoffman (31), van Genuchten and Hoffman (36), Dirksen and Augustijn (17) and Homaee et al., (23) were evaluated. The experiment was conducted under four salinities including 1.175, 3, 5, and 8 dSm-1 and four nitrogen levels including 100, 75, 50, and 0 percent of fertilizer requirements each with three replicates. Results indicated that from among the evaluated models, the derived models of MB and Maas and Hoffman (MB-MH) (nRMSE=4.9), MB and van Genuchten and Hoffman (MB-VG) (nRMSE=5.4), and also MB and Homaee et al., (MB-H) (nRMSE=7.0) provide best fits to the measured data. Also, the comparison of two modified LS and MB models indicated that the estimated relative yield for irrigation water salinity levels by modified LS model (nRMSE=4.6) provides better results (nRMSE=5.9). However, for soil nitrogen levels and interactive effects of salinity and nitrogen, the modified MB model (nRMSE=10.3) provided better outputs (nRMSE=14.4). Consequently, instead of the modified LS and MB models the proposed models in this research can be recommended for use.


Assessing the Impact of Climate Change on the Inflow on Zayandehrood Dam
S. Khalilian, M. Sarai Tabrizi, H. Babazadeh, A. Saremi,
Volume 24, Issue 4 (Winter 2021)
Abstract
In the present study, the SWAT hydrological model was developed for the upstream of the Zayandehrood dam to evaluate the inflow to this dam. Accordingly, after entering the meteorological and hydrometric information of the region, the runoff simulation was performed. Due to the high volume of entrances to the Zayandehrood Dam, Shahrokh Castle hydrometric stations were selected as the base station for calibration and validation during the statistical period of 1990-2015. After hydrological simulation and accuracy of results, climate prediction was performed using the fifth model of the climate change for the RCP scenarios. According to the forecast, by using climate change models, the temperature could be assumed to increase in all models and the highest rate of increase would occur under the RCP 8.5 climate scenario. After evaluating climate change in different diffusion scenarios, the runoff of the basin was simulated in the SWAT model. The simulation results of runoff in the catchment area showed that although the amount of rainfall was increased in the region, increasing the temperature had a greater effect, reducing the amount of runoff in the basin. Based on the results of climate change, hydrological simulation was performed using the SWAT model. The results showed that the effect of diffusion scenarios in the region was different, causing an increase in temperature and precipitation. The highest increase was observed in the RCP8.5 scenario, which was consistent with the nature of this emission scenario, with the highest emission of greenhouse gases and carbon dioxide. Then, the evaluation of the hydrological model was done; the results showed that although the amount of rainfall in the region had been increased, the increase in temperature of this basin had a greater effect and efficiency in reducing the amount of runoff.

Analysis of Earth Dam Body Behavior under Rapid Drawdown Conditions in Reservoir Water Level by Laboratory and Numerical Methods
M. Pakmanesh, H. Mousavi Jahromi, A. Khosrojerdi, H. Hassanpour Darvishi, Hossein Babazadeh,
Volume 25, Issue 3 (Fall 2021)
Abstract
The present study is investigated the earth dam stability during drawdown based on both numerical and experimental aspects. To validate the numerical model, a model was performed experimentally. Some soil mechanic tests were carried out through the hydraulic experiments to attain the usage factors of the numerical investigation. To investigate the effect of hydraulic conductivity on the rapid drop of water level and the use of hydraulic parameters of materials, seepage flow in the model was modeled by seep/w software. The input information to the software including hydraulic conductivity and water volume were measured by performing a constant load test and using a disc penetration meter, respectively. After validation of hydraulic conductivity with the experimental model, the results were compared with observed data. Comparison between numerical and laboratory discharge illustrated that the numerical model with laboratory model is well confirmed. In addition, saturated and unsaturated simulations demonstrated that the unsaturated model is highly consistent with the experimental model. It is assumed that due to the drawdown conditions, unsaturated models can achieve high accuracy for simulating the flow through a homogeneous earth dam.

Cavitation Risk through the Bottom Outlet of the Dam Using Numerical Solution of Ansys Model
A. Kasra, A. Khosrojerdi, H. Babazadeh,
Volume 26, Issue 1 (Spring 2022)
Abstract
Abstract
The objective of the present research was to investigate the flow properties through the bottom outlet of the Nesa dam based on numerical and experimental studies. 22 piezometers were employed to measure the static pressure through the experimental model. The bottom outlet section was divided into three blocks to measure the endangered region. The graph of cavitation numbers was plotted for different flow discharge and cavitation damage levels to compare with a safe zone to find out the areas with a high risk of cavitation. The results illustrate that block No. 1 cavitation index is located at the “possible cavitation” damage. The studies showed that the cavitation index is the dependent parameter with the height of the water at the upstream reservoir. Furthermore, for block No. 2, the level of cavitation ranged from x/L = 0.44 to 0.90 and the cavitation level is related to the velocity, and by increasing the velocity to 16 m/s, the threat of the cavitation and its consequences is raised, dramatically. Regarding block No.2 and 3, the cavitation through this block depends on the negative pressure since the negative values of the cavitation index is related to the negative static pressure and it is assumed that the negative pressure can reach the threat of major damage. Also, a comparison between different numerical turbulence models illustrates that the k-ε RNG with fine mesh showed less error with experimental values which causing the numerical model with this condition to reach an appropriate agreement between numerical and experimental simulations.
Numerical Study of the Rough Bed Impact on Energy Dissipation and Cavitation on Chute Spillways
H. Noury Hasanabady, M.r. Kavianpour, A. Khosrojerdi, H. Babazadeh,
Volume 26, Issue 3 (Fall 2022)
Abstract
Using a rough bed for spillway compare to common dissipation methods such as stilling basins, stepped spillways, ski jumps, and bed elements may be more efficient to boost energy dissipation. In this research, the impact of spillway continuous bed roughness on energy dissipation was investigated. For this purpose, a non-dimensional relationship was developed, and by calibrating the numerical model based on the present experimental study, energy dissipation over the spillway for three slopes of 15, 22.5, and 30 (degree) with six roughness sizes of 0.0, 0.005, 0.0072, 0.0111, 0.016, and 0.022 (m) and three discharges of 170, 110, and 90 (lit/s) was investigated. Based on the present results, using a rough bed spillway will increase energy dissipation. Also, the ratio of energy lost per meter length of rough bed spillway to that of smooth spillway increases by chute slope. The results showed that the highest amount of relative energy consumption in the presence of roughness was related to the slope of 22.5 degrees and 22.2 mm for roughness (85%), and the lowest relative energy consumption was observed in the control state (25%). As a result of the present study, a natural rough bed without concrete coating has befitted in terms of environmental aspects, construction cost, and energy loss.

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