Showing 25 results for Honar
M. Mojtabaie Zamani, M. Esfahany, R. Honarnejad, M. Alahgholipour,
Volume 10, Issue 4 (winter 2007)
Abstract
Relationship between grain filling rate , grain filling duration, yield components and other physiological traits of rice was investigated in 93 genotypes of rice at Rice Research Institute of Iran (Rasht, Iran) during the growing season of 2001-2002. The experiment was performed without any statistical design. Panicles of main stem were tagged and taken at 3- day intervals during the grain filling period. A cubic polynomial model was used to fit the grain dry weight data (mean of R2= 0.98 for all genotypes) and the grain filling rate and duration estimated for the genotypes. Traits related to sink capacity such as grain weight, grain size and grain number per panicle correlated with grain filling rate but source -capacity- related traits except chlorophyll content of flag leaf and secondary leaf did not correlate with grain filling rate. Stepwise regression showed that final grain weight, grain filling duration and flag leaf angle contributed to grain filling rate, however, path analysis showed that only final grain weight and grain filling duration had the greatest effect on grain filling rate. The results of stepwise regression irrespective of final grain weight showed that chlorophyll content of flag leaf, grain width, grain filling duration and grain length contributed to grain filling rate. Path analysis results showed that the final grain weight had the greatest direct positive effect on grain filling rate, while grain filling duration had negative effect on grain filling rate.
R. Honarnejad,
Volume 11, Issue 41 (fall 2007)
Abstract
Six Iranian rice cultivars (Binam, Domsiyah, Shahpasand, Sepidrud, Khazar and Valed 46) were crossed in 1989 in the Iranian Rice Research Institute in Rasht, Iran in a full-diallel design. The F1 progenies together with parents were transplanted in a CRBD in the 5 x 0.75 m plots at plant density of 25 x 25 cm (60 plantlets per plot) in 3 replications. Part of this research was published in 1994 as a half-diallel design and the data of full-diallel, using Griffing approach, is subject of this paper. The analysis of variance showed significant differences among genotypes. The mean of six parents, 15 crosses and 15 reciprocal crosses were analyzed using the four diallel crossing systems of the Griffing approach. The SS of genotypes were separated into GCA for each parent and SCA for each cross using corresponding formula. The additive variance (VA) and dominance variance (VD) values were estimated using the table of variance analysis. The heritability (h2ns) was also estimated from VA and VD variances. The simple variance analysis of “grain yield per plant” and other agronomic traits using each of the 4 diallel crossing methods of Griffing showed significant differences (P < 1%) among genotypes, indicating a sufficient genetic potential of the investigated genotypes. The GCA variance analysis of the lines was significant for all the characteristics, indicating the importance of additive variance (VA) by inheritance of these traits. Using Griffing’s diallel methods 1 and 3, SCA variances for all investigated traits showed significance, whereas in the methods 2 and 4, traits “1000 grain weight” and “tiller per plant” were not significant according to SCA. This also indicates the importance of dominant variance (VD) in most of the traits, except for “1000 grain weight” and “tiller per plant”. The differences among the reciprocal crosses in diallel methods 1 and 3 were also examined where for all the characteristics (except for “deaf grains per panicle” and “length to breadth ratio of brown rice grain”) significant differences were observed, suggesting the possibility of cytoplasmic effect of mother line on the reciprocal crosses. The heritability (h2ns), which indicates the ratio of additive variance (VA) to phenotypic variance (VP), was estimated to be equal to zero due to the absence of additive variance for grain per panicle and the number of days from transplanting to full maturity of grain. The heritability for other characteristics was estimated high or low according to additive variance. For example in all 4 diallel methods the heritability estimation for length to breadth ratio of brown rice grain was relatively high (65 – 71%) whereas for “panicle length” and “grain yield per plant” was relatively low (13 – 48%). The correlation among genetic parameters (VA, VD, D, h2ns ) were generally high and significant.
M. K. Shaabani, T. Honar, M. Zibaei,
Volume 12, Issue 44 (summer 2008)
Abstract
Limitations of rainfall and surface water resources farmers have to use both surface and subsurface resources for growing different crops. In this study optimal management of irrigation water allocation and cropping pattern utilizing conjunctive use of surface and subsurface water resources is studied. Also the effect of reducing water consumption in different growth stages with different irrigation strategies for major crops (wheat, barely, corn, sugar beet, rice) in Fars province was studied. The results of the study showed that optimal cropping pattern for the first season would be mainly wheat and in the second season would be corn and rice. Also in this model different policies for decreasing water demand were studied. Since crop water requirement in the second season is higher than the first season, therefore restriction on including high water consuming crops in the second season would be the best choice in the cropping pattern.
A Shaabani, A Kamgar Haghighi, A Spaskhah, Y Emami, T Honar,
Volume 13, Issue 49 (Water and Soil Science 2009)
Abstract
Oil seed rape (Brasica napus) is an important crop, which is cultivated in Iran for oil production. As a management practice deficit irrigation strategy is applied to cope with water shortages, especially during drought periods. This research was conducted to study the effect of water stress on physiological parameter of oil seed rape in the experimental research field of Collage of Agriculture (of shiraz university) during 2004- 2005 and 2005- 2006. Licord cultivar of oil seed rape was planted and experimental design was random block with five treatments and four replications. Treatments were full irrigation in all growth stages, water stress in vegetative stage in early spring, water stress in flowering and podding stages, water stress in grain filling stage and dry land treatment with supplemental irrigation in time of planting. Water stress caused decrease in water potential of plant, an increase in canopy temperature, and decrease in plant height especially in dry land treatment. Leaf area index decreased as water stress increased. The decrease in leaf area index was more severe in vegetative stage water stress treatment. At the end of water stress period leaf area index increased again. Rate of decrease in leaf area index at the end of the growing season was higher in grain filling stage of water stress treatment.
A Karizi , T Honar ,
Volume 14, Issue 51 (spring 2010)
Abstract
Side weirs as flow diversion devices are usually used as emergency weirs in large hydraulic structures like dams and irrigation and drainage networks, because of their importance they require delicate design. As a result application of numerical and simulation models play an important role in design of these hydraulic structures. In this research, the flow pattern and shear stress distribution on broad crested side weirs with different widths and entrances along with different discharges were studied by numerical solution under two and three dimensional conditions and then the results were compared with laboratory findings. These experiments were conducted in a rectangular channel with one side weir and a length of 70 cm. Experiments were done considering rounded and sharp entrances with different rounded radii and one constant discharge with intake proportions of 40 and 60 in main and branch channels, respectively. Comparison of numerical solution and experimental results show that side weirs with rounded entrance had a noticeable shear stress reduction (arrived in the bed and sides) and non-effective spinal flow, resulting in increased intake efficiency.
T. Honar, A. Sabet-Sarvestani, A. Sepaskhah, A. A. Kamgar-Haghighi1, Sh. Shams,
Volume 16, Issue 59 (spring 2012)
Abstract
In recent years, simulatiom modelling of yield has been the focus of attention for many researchers. Because, while reducing adminestrative costs, it can easily provide simulation models of different situations. In this study, while a subroutine on simulation of canola was added to CRPSM model, effect of different water treatments on canola was also investigated. In this research, canola (Talaye) under 5 irrigation treatments (full irrigation treatment during the growing period, water stress treatment at the spring re-growth stage, the flowering stage and pod formation, the grain formation stage and dry land treatment) was sown in complete randomized block designs at the college of Agriculture, Shiraz University during 2007-2008, and then the model was calibrated based on available information (soil-location -plant-water). Review of statistical indicators between simulated and measured yield show high accuracy in the estimation of crop yield (R2=0.98) and soil water content. The result of model validation with independent data series also showed that the result of soil water content is desirable except in dry treatment, and the corrolation coeficient between simulated and measured crop yield (R2=0.98) was acceptable.
M. Fathi, A. Honarbakhsh, , M. Rostami, A. Davoudian Dehkordi,
Volume 16, Issue 62 (Winte - 2013 2013)
Abstract
The present paper tries to describe the advantage and improvement of a numerical model when predicting government processes on Flow Rivers. With regard to the important effect of the flow velocity and shear stress forces on river bank erosion, we apply a Two-Dimensional numerical model, named CCHE2D, to simulate river flow pattern at a meandering river Khoshk-e-Rud River of Farsan, 30 Km west of Shahr-e- Kord. Various algorithms and parameters were implemented in a computational fluid dynamic model (CFD) for simulation of two-dimensional (2D) water flow to gain an insight into the capabilities of the numerical model. At this surveying, at first, we applied the topographic maps of the studied location and then, made the model geometry and calculation mesh with diverse dimensions. Finally, using the measured properties of the river flow and the Depth-Average, Two-Dimensional Hydrodynamic Model was run. Then, we obtained the results of model, such as depth and flow velocity at the river meander. Within the scope of the test cases, the model simulated water flow pattern processes at an intake, as well as a steady flow regime in a sine-shaped meandering channel by a 90_channel bend, which is the free-forming meander evolution of an initially straight channel. Because of high accuracy of this numerical model and multiple content of its internal parameters, the evaluation result of model, confirmed the measurement results. Therefore, the parameters gained from the model showed good conformity with measurement parameters at field cross-section. All results matched well with the measurements. The results also showed that using computational fluid dynamics for modeling water flow is one step closer to having a universal predictor for processes in Meandering Rivers
N. Pourabdollah, T. Honar, R. Fatahi,
Volume 18, Issue 67 (Spring 2014)
Abstract
Most of researches related to hydraulic jump have been done on horizontal and rough beds, and little attempt has been made on rough beds with adverse slopes. The aim of this study was to investigate the influence of rough beds with adverse slope on hydraulic jump characteristics. The variations of energy loss in stilling basins with three adverse slopes and three different roughnesses were studied. Results showed that increase of roughness caused that relative depth of jump in stilling basins with rough bed and adverse slope decreased as compared to horizontal smooth beds. The experiments were performed on rough beds in different conditions where Froude number ranging between 4.9 and 7.8. Result showed that reduction of relative depth was about 31.15%. Results also showed that in such cases the relative energy losses are more than that for classic conditions.
T. Honar, S. Mazloom Shahraki,
Volume 18, Issue 69 (fall 2014)
Abstract
Cylindrical and semi-cylindrical weirs are used in water distribution systems for flow measurement in open channels and for control of water surface. Review of literature shows that cylindrical and semi-cylindrical weirs are not widely used in practice. Because of their low construction cost and simplicity, an investigation was done to study cylindrical and semi-cylindrical weirs in terms of their hydraulic characteristics such as discharge coefficient, energy loss and flow depth over the spillway crest. The research was done for 128 models in the hydraulic laboratory of water engineering department, Shiraz University. According to the results, due to flow separation from body of the weirs, flow coefficient increases in the cylindrical and semi cylindrical weirs by 57%. It was found that discharge coefficient increases by increasing the total head of upstream. Therefore, construction of cylindrical and semi-cylindrical weirs and side weir is recommended due to reduction in weir length, increased hydraulic efficiency, and reduced administrative costs compared to other wide edge side weirs.
A. Ahmadi, T. Honar,
Volume 18, Issue 70 (winter 2015)
Abstract
One of the most important problems in the design of a stilling basin is determination of the exact location of the hydraulic jump or stabilization of the hydraulic jump. In the present study, the effects of different forms of end sills on hydraulic jump characteristics were studied. The experiments were carried out for three different forms of end sills, rectangular, square and stepped, with three heights in two distances and for Froude numbers in the range of 4.7-8.23. The results showed that the end sill with larger cross section (square and stepped) will have a greater effect on reducing sequent depths of hydraulic jump and increasing energy loss than narrow end sills. However, in this type of end sills, water fall and the risk of erosion at downstream is greater.
Z. Abdollahian Dehkordi, Kh. Abdollahi, S. J. Sadatinejad, A. Honarbakhsh, M. Nekooeimehr,
Volume 19, Issue 71 (spring 2015)
Abstract
Achievement to sustainable development is dependent upon integrated watershed management. In other hand without detailed analysis of the rainfall - runoff observations, high risk of flood predictions will be translated into flood-induced capital losses. Considering the fact that not always hydrometric data are available, using synthetic unit hydrograph is one of the most popular methods of flood simulations for ungauged watersheds. This method has operational limitation for duration of runoff but in Instantaneous Unit Hydrograph (IUH) assumed to all take place at a discrete point in time therefore can be converted into and desired durations.According to literature few studies have been focused on Laplace transforms, H2U-Nash Unit Hydrograph in Iran, this work is an attempt to investigate model performance in Jooneghan catchment, located in northern part of Karoon great basin.Laplace synthetic hydrograph was derived base on effective rainfall while H2U-Nash model was simulated using moments technique and lag time.The mean absolute relative error of Laplace transforms, H2U-Nash was 0.42 and 0.25 respectively. Visual interpretation and statistical comparison of Nash-Sutcliffe efficiency coefficient of the models confirms that H2U-Nash model performs better than Laplace transforms model.
M. Zare , T. Honar1,
Volume 19, Issue 74 (Winter 2016)
Abstract
The most important cause of concern about the stability of bridge foundation is the occurrence of scour around bridge piers. Therefore, different methods have been proposed to prevent or reduce scouring around bridge piers. The use of groynes is one of the modern methods to control and reduce local scour. In the present study, the effect of a solid groyne on reduction of the scour depth around a cylindrical bridge pier, located in the bend of a laboratory flume is assessed. Experiments were conducted for groyne model angled at 50˚, 90˚ and 120˚ to the downstream channel sidewall with three flow rates of 47, 49 and 51 liters per second in a sediment free condition. Results showed that in at ratios of velocity to critical velocity and all groyne angles, in comparison with no groyne, the scour depth was reduced. At all ratios of velocity to critical velocity, the best operation was related to normal groyne and the average operation of repelling groyne was better than attracting groyne. The operation of normal groyne decreased and attracting groyne function improved as the flow rate increased. Also, the normal groyne (ratio of velocity to critical velocity equal to 0.87) had the best effect on reducing the scour depth (by about 71.4 percent).
M. Omidvar, T. Honar1, M. R. Nikoo, A. R. Sepaskhah,
Volume 20, Issue 76 (Summer 2016)
Abstract
At the river catchments, different strategies at the whole or different parts of the basin can be applied for water resources management. One of these strategies is optimal water allocation and crop pattern. In this study, an optimization model for water allocation and cropping pattern is presented based on the cooperative game theory. To measure the performance of the developed model, the cultivated area of Ordibehesht Canal in the Doroodzan irrigation network has been studied. First, using a fuzzy model and considering the fuzzy coefficients values in the objective function and constraints, the optimal crop pattern and allocated water has been determined for each crop. Second, benefits of stakeholder’s coalitions have been determined by developing a cooperative game model and based on the structure and properties of the irrigation water distribution network and water rights of each part. Then, the total net benefit has been reallocated to the different stakeholder in a rational and equitable way using Least Core games. The results show that by allocating more water to the sectors with more potential production, more profits are generated and water productivity increases. For example when players cooperate together and form the grand coalition, the net benefit increases from 8.906 billion Tomans to 9.724 billion Tomans that show an increase in the economic productivity of water.
A. Honarbakhsh, M. Pajoohesh, M. Zangiabadi, M. Heydari,
Volume 21, Issue 4 (Winter 2018)
Abstract
Nowadays, human interferences in the natural resources cause the loss of these resources and lead to destructive floods, soil erosion and other various environmental, economic and social damages. Furthermore, increasing growth of population and climate change intensify the destructions. Thus management and planning through land use optimization is essential for the proper utilization, protection and revival of these resources. The purpose of this study is to couple the fuzzy goal programming and multi objective land allocation optimization approaches to develop a model for watershed management and planning in Chelgerd watershed. The proposed model is based on optimum area determination in various land uses and also their optimum local situation. In this research, a fuzzy model has been proposed. In this model, minimizing the amount of soil erosion and maximizing the amount of profit are priorities, respectively. Moreover, production resources including water and land as well as economic and social problems are limitations of the mentioned model. Results obtained show that the proposed model is an efficient model in land use optimization and sustainable area development and can increase profit to 37% and decrease sedimentation to 2.4%, respectively.
A. Honarbakhsh, M. Fathi, M. Rostami,
Volume 23, Issue 4 (Special Issue of Flood and Soil Erosion, Winter 2019)
Abstract
In general, rivers are one of the best and most accessible water resources at the disposal of mankind. So, given the effect of the force of water and changes on the flow patterns and consequently, on river morphology changes, the analysis of the flow in the river is important and necessary to organize projects, flood control and water supply structures downstream. In this study, by using numerical models CCHE2D hydraulic conditions Dimeh River Bridge between Oregon Bridge Sudjan was investigated. CCHE Model is a mathematical model capable of simulating the flow patterns and sediment transport in rivers and canals laboratory network. The numerical model in 1998, based on the calculations by the National Centre for Water Science and Engineering, University of Mississippi (NCCHE), was developed and has been applied in many research projects related to water engineering. At the outset, the input data required model provides and numerical model was implemented. In the next step, the results of the model were calibrated and validated using field data measurements; eventually, they were extracted and their model results were compared; it was confirmed that CCHE model could still simulate the flow pattern.
H. Siasar, T. Honar, M. Abdolahipour,
Volume 23, Issue 4 (winter 2020)
Abstract
The estimation of reference crop evapotranspiration (ETo) is one the important factors in hydrological studies, irrigation planning, and water resources management. This study attempts to explore the possibility of predicting this key component using three different methods in the Sistan plain: Generalized Linear Models (GLM), Random Forest (RF) and Gradient Boosting Trees (GBT). The maximum and minimum temperature, mean temperature, maximum and minimum humidity, mean humidity, rainfall, sunshine hours, wind speed, and pan evaporation data were applied for years between 2009 to 2018. Using various networks, the ETo as output parameter was estimated for different scenarios including the combination of daily scale meteorological parameters. In order to evaluate the capabilities of different models, results were compared with the ETo calculated by FAO Penman-Monteith as the standard method. Among studied scenarios, M1 covering the maximum number of input parameters (10 parameters) showed the highest accuracy for GBT model, with the lowest RMSE (0.633) and MAE (0.451) and the maximum coefficient of regression (R = 0.993). Air temperature was found as the most sensitive parameters during sensitivity analysis of studied models. It indicated that accuracy and precision of temperature data can improve the results. Application of the GBT model could decrease the time consumed to run the model by 70%. Therefore, the GBT model is recommended for estimation of ETo in the Sistan plain.
M. Pajoohesh, M. Mohammad Yousefi, A. Honarbakhsh, H. R. Reyahi Bakhtyari,
Volume 24, Issue 1 (Spring 2020)
Abstract
In order to plan and manage the land and its changes, it is necessary to identify and evaluate the factors affecting it. Land use / cover changes are one of the main factors in global environmental change that is defined as a change in the type of land use; it is one of the major factors changing hydrologic flow, land erosion and destruction of biodiversity. The main purpose of this study was to assess the trends of land use changes in Beheshtabad Watershed of Chaharmahal and Bakhtiari Province with an area about 3847 square kilometers by using remote sensing and GIS during a 25-year period. In this research, first, analyzing and pre-processing the satellite images of Landsat 5 TM sensors from 1991 and 2008 were done, and Landsat 8 of OLI sensor of 2016 was applied. Then, by using the hybrid classification method, 5 land use classes including pasture lands, urban-building lands, agricultural lands, garden lands and bare lands, land use maps for the three time periods were prepared. The overall accuracy of the obtained land use maps for 1991, 2008 and 2016, was 92.17%, 94.29% and 93.41%, respectively, indicating the acceptable accuracy of the maps. Then, the process of land use change and the contribution of each land use classes and the percentage of changes in each land use class were determined in two study periods. The results of this study showed some changes occurred in the studied watershed. The total area of pasture lands during two periods indicated the decreasing trend, but urban-building and garden lands during two periods represented the increasing one. Agricultural lands during the first period indicated the decreasing trend and during the second period showed the increasing trend, while bare lands during the first period showed the increasing trend and during the second period, reflected the decreasing trend. In general, it should be noted that in the Beheshtabad watershed, we could see an increase in the replacement of pastures by urban-building class, rainfed agriculture, gardens, and bare lands, the incidence of destruction in the region.
S. S. Ariapak, A. Jalalian, N. Honarjoo,
Volume 25, Issue 2 (Summer 2021)
Abstract
In this study, spatial-temporal variation of dust deposition rate in the western and eastern half of Tehran and its climatic parameters affecting were studied. At 34 points in the city, dust samples were collected by glass traps from the roof, for twelve months, and the climatic data were obtained and analyzed from relevant organizations. The highest deposition rate is in the western half of the city and its total amount has varied from 54.52 to 121.21 g/m2/y. In both halves of the city, summer has the highest dust deposition rate and its central areas have the highest amount. There were significant positive correlations between dust deposition rate with temperature and medium wind speed, and there were significant negative correlations between dust deposition rate with rainfall and relative humidity in all months, which justifies the high dust deposition rate in the dry seasons of the year. The results of stepwise regression showed that rainfall was the most important factor affecting the dust deposition rate in both halves of the city. The city of Tehran has a special geographical location the presence of mountains like a barrier has prevented dust from leaving the city and the air inlet corridor of Tehran has faced problems due to the expansion of building construction and high-rise building. Other factors affecting the rate of dust deposition in this city, in addition to the distance from the main source of dust production, atmospheric parameters can be mentioned the existence of barren lands around the city, vegetation cover, construction operations, and traffic.
H. Alipour, A. Jalalian, N. Honarjoo, N. Toomanian, F. Sarmadian,
Volume 25, Issue 4 (Winiter 2022)
Abstract
Dust is one of the environmental hazards in arid and semi-arid regions of the world. In some areas, under the influence of human activities, dust is contaminated by heavy metals. In this study, the dust of 10 stations in the Kuhdasht region of Lorestan province in four seasons of spring, summer, autumn, and winter, as well as adjacent surface soils (a total of 40 dust samples and 10 surface soil samples), were sampled and some heavy metals including Zn, Pb, Cd, Ni, Cu, and Mn were analyzed. The results revealed that the amount of Zn in the dust was much higher than the surface soils of the region (800 vs. 85 mg/kg). Contamination factor index calculation indicated that high contamination of Cd and Zn, significant contamination of Ni and Pb, and lack of contamination by Cu and Mn. The annual enrichment factor of Cd (33.9) and Zn (24.6) was very high, Ni (11.3) was significant, Pb (6.4) was moderate, Mn (1) and Cu (0.82) were low. Based on the enrichment factor values, Cd, Zn, and Ni seem to have a human origin, Pb has both human activities and natural origin, and Cu and Mn have an only natural origin.
E. Javiz, A. Jalalian, M.r. Mosaddeghi, E. Chavoshi, N. Honarjoo,
Volume 26, Issue 4 (Winiter 2023)
Abstract
One of the most significant environmental crises in arid, semi-arid, sub-humid, and even humid regions is the destructive phenomenon of desertification and in the arid and semi-arid regions is wind erosion. These problems exist in large areas of Iran and it is necessary to use an environmentally friendly and economic method to solve this problem. In this study, calcium bentonite clay was used for the first time in Iran and perhaps in the worlds in the critical region of Sajzi, which covers an area of 65 hectares. Experiments were performed on the crusts after one year of mulching with bentonite clay. The results showed that wind erosion has a negative and significant correlation with the mean weight diameter and geometric weight diameter of aggregate, aggregates with diameters greater than 0.25 mm, shear strength, and penetration resistance. On the other hand, the results of the permeability test using double-ring and by three models (Kostiakov, Horton, and Philip) showed that the lowest mean square error (SSE) and the highest coefficient of determination (R2) belonged to the Kostiakov model in the mulch-applied and control samples. This result indicated the superiority of the Kostiakov model compared to Horton and Philip's models. Wind erosion intensity was also measured in situ using a portable wind tunnel at 20 points in the Sajzi region. The findings showed that mulch application has controlled more than 95% of soil erosion.
