فهرست مطالب mohammad shayannejad

The purpose of this study was to determine the yield potential of winter wheat (Triticum aestivum) in Isfahan province and the appropriate cultivation date in different regions of the province using the CSM-CERES-Wheat plant model. For this purpose, 63 main areas of wheat cultivation were selected and their soil information was entered into the model. The model was run using meteorological data for 63 soil profiles, 18 different planting dates and 15 common wheat cultivars in the province with agronomic management without water and nitrogen stress. Average biomass production potential in the study area was 26392.47± 780.99 kg ha-1, grain yield 11914.17±442.62 kg ha-1, water productivity (WP) 1.73±0.11 kg m-3 and irrigation water efficiency (WPi) was 2.49±0.30 kg m-3. WP of the eastern regions of Zayandehrud basin (Varzaneh, Kabutarabad and lenjanat) was 12.82% higher than the western regions (Fereydunshahr, Fereydan and Chadegan) and WPi for the western regions was 16.30% higher than the eastern regions. In western and northwestern regions of the province, the production portion of green water is 38.31% and in eastern regions of the province is 18.86%. therefore, it is recommended to use the capacity of green water under any conditions in the western and northwest regions in addition to planting on suitable dates. Planting dates varied for different regions depending on whether the goal was to maximize the yield or water productivity index. Suitable planting date was obtained as following: for Fereydan, Fereydunshahr and Chadegan regions 26 September to 15 October, Khansar and Tiran 26 September to 25 October, Golpayegan 5 October to 5 November, Lenjanat, Najafabad, Kabutarabad and Varzaneh 15 October to 25 November.

The aim of this study was to investigate the effect of using each of the surface, sprinkler and drip irrigation methods on the condition of Zayandehrud basin. For this purpose, water, energy, food and carbon nexus approach was used for a comprehensive study. In the nexus approach, considering their interactions, efforts are made to increase productivity and ensure the security of the region. In this study, this approach has appeared in the form of a newly developed index called water, energy, food and greenhouse gases nexus (WEFGN) and considering ten indicators including inputs of crop production, energy consumption for irrigation, food self-sufficiency, economic efficiency and carbon emissions were studied for irrigation methods that could provide a comprehensive view of managers and decision makers. The results of the study of irrigation methods in 2020 showed that by changing the current irrigation method to drip and sprinkler irrigation due to reduced water consumption (17 and 4.84 percent (483.7 and 138.5 million cubic meters per year, respectively)) the condition of the basin improves, but in the sprinkler method more energy is needed for irrigation (280.5 percent (112415.8 thousand kcal per year)) and the carbon released due to the increase in irrigation energy also increases to 87432.5 tons per year (73.7 percent). Therefore, the WEFGN index score for each of the drip irrigation, sprinkler and current status methods was 0.86, 0.31 and 0.47, respectively, and the best irrigation method in Zayandehrud basin in terms of nexus approach was drip irrigation.

Soil salinity and sodicity is a world-wide problem of irrigated farmlands that threaten soil quality and crop productivity in arid and semi-arid regions. Soil salinity refers to the accumulation of salt in the plant root zone which reduces plant growth. The use of saline and sodic groundwater for irrigation purposes deteriorates soil quality, causing clay dispersion, and reduction in hydraulic conductivity and plant available water. It also negatively affects plant physiological parameters such as reduction of grain yield, shoot and root length, biomass, rate of photosynthesis, leaf water potential, and increases proline content. Therefore research on possible amendments for the soils in these systems is necessary. Different organic and inorganic amendments are used to address salinity problems in agricultural soils. Common organic amendments include animal manures, agricultural residues, green wastes and biochars, and the inorganic amendments include gypsum, zeolite and super absorbents. In this study, the application of biochars produced at pyrolysis temperatures of 300 and 500 °C and their feedstocks as well as a superabsorbent (SA) on the leaching of salts through the soil columns were investigated.

The experiment was carried out in the Irrigation Laboratory, Department of Irrigation, College of Agriculture, Isfahan University of Technology, Iran, in 2018. The experiment was conducted as a completely randomized design with three replications. A saline-sodic soil (0–30 cm layer) was sampled from the Rodasht Soil Salinity Research Center, located in the east of Isfahan, Iran. The soil was classified as Typic Haplosalids, soil texture was silt loam and comprised 610, 180 and 210 g kg-1 silt, sand and clay, respectively. Five combinations of sugarcane bagasse, rice husk, cow manure, and pine wood were considered and pyrolyzed at 300 °C and 500 °C under oxygen-limited conditions (continuous inflow of nitrogen) for 2 hours (slow pyrolysis) in a pyrolysis chamber. A control with no amendment (CT), a super absorbent (Stockosorb) (SA), feedstocks (BWM, RWM, WM, BWMR and BWR), and their biochar produced at 300 and 500 °C were considered. The five combinations were pyrolyzed at two temperatures of 300 and 500 °C to obtain the biochar samples. Then the feedstocks and their biochars, as well as the SA sample, were applied to the saline-sodic soil and incubated in sealed plastic bags at a water content of 80% of the soil plastic limit, and room temperature (25 ± 1°C) for 40 days. After the incubation, the amended soils were packed into soil columns (PVC pipes) of 15 cm diameter and 50 cm height, and leached with 4 pore volumes (PV) of irrigation water. The PV was determined using the porosity and volume of the soil column. A constant water height of 5.0 cm was held on the soil surface by a mariotte bottle. The saturated hydraulic conductivity (KS) of the soil and the leachate electrical conductivity (EC) were measured during the leaching period at every 1/3 PV leaching. After leaching, the soil samples were carefully collected from the columns. Then the soluble ion concentrations (Mg2+ and Ca2+) were determined.

At a given period, there was a lower EC of the leachate for the BWR (sugarcane bagasse, rice husk and pine wood) treatment compared to the other amendments. The KS of soil increased significantly with the application of all amendments, which could be related to the improvement of soil structure, and increased porosity and leaching of sodium. The lowest KS was observed in control, which could be related to exchangeable sodium between the solution and the soil exchange sites, and soil dispersion. The biochar treatments had less Mg2+/Ca2+ ratio than their feedstocks and subsequently, the soil aggregate stability increased in the biochar treatments. Soil quality is influenced by the physical properties of amendments that are applied to the soil. It is important to consider the pH and EC of biochar for soil amendment. The BWR combination had the lowest EC and pH compared to other combinations. Also, the BWR had the highest C/N ratio compared to other combinations, subsequently, the KS increased. Overall, this study suggested that the use of BWR300 (the biochar of BWR compound produced at pyrolysis temperature of 300 °C) and SA amendments might be suitable for the improvement of saline-sodic soils in arid and semi-arid regions. Further experiments are needed to determine the rates of amendments for different soil types and water qualities in the long–term periods and large-scale applications in saline-sodic conditions.

Water resources are limited in many areas of the world; sometimes, even these limited resources are negligently contaminated. One of the polluting factors of water is oil and its derivatives. Oil absorption using textiles is one of the common ways to separate oil from water. In this study, we used three types of textiles with different properties in order to make the filter. The experiments were performed using three different concentrations of 10, 20 and 30% oil. In this study, three types of BC, PET and PP textiles in the presence of horizontal and vertical drainages were investigated. The PET and PP textiles were made of nonwoven polyester and polypropylene fibers, respectively, and the BC textile was a two-component nonwoven textile of both polyester and polypropylene fibers that was used for the first time. Flow through the textiles was turbulent. Coefficients of flow were calculated using non-Darcy flow relations and the optimization method. The results showed that at low oil concentrations, the oil absorption had an inverse relation with the porosity and turbulent flow coefficients, but at higher concentrations, the effect of these agents was less; instead, the effect of the concentration and the intrinsic ability of the non-woven fibers was greater.  The best performance was related to PP and PET with the horizontal drainage that had 95 and 91 absorption rates, respectively.

Darcy's law is valid for laminar flow and its application is not recommended for turbulent flow. The turbulent flow equations are derived based on hydrodynamics principals with introducing turbulence effects. The purpose of this research is to derive the relationship between discharge and hydraulic potential in radial flow in unconfined aquifers under steady state. The basis of the relationship is fractional derivative approach of the velocity flow related to the hydraulic gradient. The previous study data was used for the verification of the derived equation. The profile of the water level was computed and plotted for different porous media with non-Darcy flow in unconfined aquifer for different discharges based on the extracted equation and compared with the results of the Darcy's law. The results showed with increasing the discharge values the highest and lowest increament of water level were 10 and 1.48% related to Darcy flow respectively. These values for increasing of hydraulic conductivity were 19 and 9.8% respectively. Overall, the difference between the Darcy and non Darcy flow in water level estimation increased with increasing discharge and hydraulic conductivity as well as the increase of both parameters, which water level was higher in Darcy flow than non Darcy flow in all water profile profiles.

Reduction of water resources in arid and semi-arid areas requires the application of management methods to achieve optimal performance. With the logical application of saline water as a source of irrigation water, we can supply a part of the crop water requirement (Hamdy, A., Abdel-Dayem, S. and Abu-Zeid, M., 1993), using various applicable management techniques. The optimal management is, in turn, considered as the use of conjunctive irrigation. Two commonly used solutions include mixing salty and fresh water to obtain water with the optimal salinity; and also the periodic application of fresh and salty water (Amer, 2010; Aslam, & Prathapar, 2006). In effect, salt mainly enters the surface layers of the soil through irrigation and the solute moves vertically from the unsaturated to the saturated zone and towards the groundwater. In turn, the SWAP model is often used to simulate the solute transfer in soil. However, field measurement of the solute concentration changes is very difficult in soil profiles. A simulation model can, thus, be used to estimate the accumulation of solutes in the soil profiles. (Van Dam, Huygen, & Wesseling, 1997)

Pistachio is the most important export product of Iranian agricultural sector. This product is very important because of valuation, job creation, value added as well as tolerance to salinity and drought. The purpose of this study was to investigate and analyze the evapotranspiration of pistachio (ETc and ETa), gross water requirement (IWR), and depth or volume of water used in pistachios (AW) in several selected gardens in Bahadoran region of Yazd province. The study area is one of the pistachio growing centers in Yazd province. The results show that the total annual irrigation water depth in the selected orchards varies from 823 to 1600 mm (equal to 0.27 to 0.57 L/s/ha). However, due to the salinity of irrigation water and to overcome the problems of accumulation of salts in the soil, the hydromodule necessary to supply the water needed for pistachios varies from 0.6 to more than 1 L/s/ha. According to the critical condition of the water resources in the plain, it is virtually impossible to provide it. Also, by using Surface Energy Balance Algorithm, the actual evapotranspiration of pistachios during the growing season was 556 mm for the whole study area and 672 mm for the selected orchards. Regarding the comparisons between pistachio water demand, actual evapotranspiration, and volume of water used in the selected orchards, a managed deficit irrigation strategy can be recommended for the study area. Optimization of traditional irrigation systems, changes in water utilization system with the aim of reducing irrigation interval, considering the spatial variations of pistachio water requirement in the region, off-season leaching, and implementation of proper management at the orchard level are among the solutions that can be useful in overcoming the salinity and water shortage problems and prevent product loss.

In recent years, researchers have considered new methods such as dry drainage, to control the soil water and salinity of the irrigated area of the fields in the arid and semi-arid regions because traditional drainage methods are expensive and need more water. Investigation of water and salts transport in these systems is essential for studying their function. In this study, effect of dry drainage on the soil water content, salinity, nitrate and chloride ion concentrations in a loamy soil was investigated using a physical model under the barley cultivation. Based on the results, dry drainage led to transport a significant part of the salts entering in the irrigated area to the non-irrigated area that accumulated on its soil surface, in addition to controlling soil moisture in the irrigated area. Based on the results, at the end of the experiment, maximum increase of salinity, nitrate and chloride concentrations on the soil surface of the irrigated area were 145, 384 and 135%, respectively, and for the soil surface of the non- irrigated area were 270, 1070 and 160 %, more than of initial values at the start of the experiment. Therefore, dry drainage system was able to control the soil salinity of the irrigated area by transporting the salutes to the non-irrigated area for proper barley growth

Human activities in the fields of agriculture, municipal and industry introduce significant amounts of nutrients and organic materials into the rivers and streams resulting in their contamination. Computer models such as Qual2kw are used extensively for water quality management of rivers and streams. The Qual2kw model is a one dimensional, non-uniform, steady water quality model, which has been used by the United State Environmental Protection Bureau and was developed based on the Qual2e model. A water quality model provides a feasible framework by simulating the important physical, chemical and biological processes. Qual2kw is able to simulate a number of components including temperature, pH, carbonaceous biochemical demand, sediment oxygen demand, dissolved oxygen, organic nitrogen, ammonia nitrogen, nitrite and nitrate nitrogen, organic phosphorus, inorganic phosphorus, total nitrogen, total phosphorus, phytoplankton and bottom algae. The main equation which the aforementioned model attempts to solve is the one-dimensional convection-diffusion equation which is applied for each constituent, except for variables related to river-bottom algae. Applications of Qual2kw are found in numerous cited literature. In this paper, based on the model manual, the equations used in the modelling process are described. Also a practical guide for users who want to use this model has been presented.

Nowadays, it’s very usual to use these models in almost all sciences. use of these models has provided quick, appropriate and economic answers to many questions. Modeling is developing In different fields of agriculture, including irrigation and drainage. Field tests are useful to determine and analyze the different irrigation management but there are significant limitations. The most important limitation is the validity of the experiment that is limited by the physical conditions of the area where the experiment performes there. One of the models that is used in agricultural science is the SWAP model that is a model for simulating of soil, water, atmosphere and plant. This model is able to analyze interactions between water movement, growth of plant and transfer of solutions, prediction of yield under different regimes of water and salt, long-term simulation and irrigation scheduling. Although SWAP model is able to simulate relations between soil, water, atmosphere and plant under different management field conditions completely but it has limitations too. One of these limitations is many numbers of input data. So far many researches have been done using this model but by searching on the scientific articles, there is no complete source that offers the basic equations used in the model and also the practical guide is not available. In this article, according to the model guide, the equations that used for model calculations, has been described. Also a useful and practical guide for users who want to use this model has been presented.

In this study, a two-dimensional model is presented to design the distances between laterals and to predict the situation of water table between two lateral drainages after an irrigation or precipitation. The equation is obtained through combining continuity, Darcy and Van Genuchten equations and is solved using numerical finite difference method considering appropriate boundary conditions.. To validate the obtained model, the control profile was compared to model derived profile. The results indicated that the outputs of the model have more precision in long-term periods, and that acceptable results can be produced if numerical methods are applied to solve the flow equations. Moreover, it was found that the vertical flow is predominant above drainages axes at the onset of infiltration, while horizontal flow is predominant in long-term periods. Comparing the model to traditional draining equations for designing drainage distances, it was found that the Dum equation gives the best results, while the presented model has more precise outputs than Dum equation.

Flood routing in rivers is a mathematical procedure to determine flow hydrograph at a point in a river. One of routing methods is based on solution of Saint-Venant equations for unsteady flows. Because this method is very complex and need to more information of river, other methods with simple calculations and reasonably accurate results have been extended and give generally satisfactory results for hydrologist researchers and need to lower information of river. Muskingum model is one of these methods that accuracy in evaluation of its parameters effects on predicting flood hydrograph, especially peak rate of flow. As far as genetic algorithm is an appropriate solution to determine optimized nonlinear Muskingum coefficients, in this study we used this method to determine optimized coefficients in MATLAB and for a wide range of hydrographs getting from HEC-RAS software. Then the nonlinear Muskingum coefficients were presented as functions of river characteristics and inflow hydrograph. The model has been developed using the functions and solving of differential continuty equation with Rung-Kutta order 4. To determine the accuracy of the model, measured hydrographs of 5 floods in a reach, were compared to hydrographs computed by the model and HEC-RAS software and the results were analyzed using RMSE factor and correlation coefficient. Results indicate that there was no significant diference between the model and HEC-RAS .

In this paper, a mathematical model was used to describe the flow through a two layered rockfill dam. The coefficients of equations used were determined by an experimental model and a nonlinear optimization method. The model verification was carried out with the same model. The hydraulic flow in the porous media was not well recognized, because the flow was turbulent in these media. Thus, Darcy law was not valid in them. In this study, three power relationships between Darcy- Weisbach friction factor and Reynolds number were suggested for the three types of single layered porous media (fine, coarse and a mixture of them). By combining these relationships and continuity equation, rating equations were developed both for horizontal and vertical two layered rockfill dams, which had been made from the fine and coarse layers. These equations can be used in reservoir flood routing as rating equations. So, by introducing a hypothesis inflow hydrograph to the reservoir flood routing model, the output hydrograph can be determined, both for two types of two layered and three types of single-layered rockfill dams.

In this study, climatic parameters are used to evaluate the sensitivity of reference evapotranspiration in Isfahan and Rasht with two semi-arid and moderate climates using two intelligent methods during 1970-2010. In this research, multi-layer precpetron e (MLP) and gene expression programming (GEP) intelligent models are used in order to analyze the sensitivity of reference evapotranspiration to meteorological parameters. Results of correlation of the parameters showed, in Isfahan and Rasht, maximum and minimum temperatures have the highest correlation with correlation coefficients of 0.968 and 0.926 with other parameters, and in Isfahan wind speed and maximum temperature with a coefficient of 0.067 and in Rasht, minimum humidity and wind speed with a coefficient of 0.001 have lowest correlations. The results of the survey indicate that in Isfahan using MLP model and the maximum and minimum temperature, humidity, wind speed and number of sunshine hours as inputs, with the root mean square error (RMSE) equal to 0.418 mm/day was the best results for estimating reference evapotranspiration. The application of MLP model in Rasht, with the inputs of maximum and minimum temperature, the maximum humidity and the number of sunshine hours has less error and higher correlation coefficient and the values of reference evapotranspiration are much more similar to reality. Also, about the evapotranspiration of reference plant in relation to parameters that are used in this study the results showed that in two study places, the correlation coefficient between wind speed and reference evapotranspiration are 0.3 and 0.061 in Isfahan and Rasht, respectively which are the lowest coefficients.

Land use is one of the most important that effect on the natural cycle of water. The present study evaluates land use changes effect on Zayandehroud river flood hydrograph in Isfahan region. The land used map of the studied basin was obtained from ETM (+) 1990 Landsat and IRS 2008 satellite images using ENVI software. Runoff-rainfall events were also simulated using SCS model and the model was calibrated based on the measured hydrographs. The results showed that the coefficient of the SCS model should be considered by 0. 21 for the basin. Also the hydrograph obtained from the coupled HEC-HMS model and GIS tools showed that effect of the land use change in the flood peak flow may be decreased with increasing the return period of the floods. For example for 5 year flood، the peak discharge from year 1990 to 2008 to be increased by 39. 9 % but for the 200 year flood، the value was obtained at 10. 3 %.

Continuous and disperse blanks in most hydrological data (e. g. rainfall data) often occur due to data loss، elimination of incorrect data and the malfunctioning of measuring instruments; these then need to be estimated and/or evaluated for subsequent analysis. There are various methods available for estimating and regenerating these data، the accuracy of which depends very much on the specific conditions of the station، so that one specific method may suit a particular station. Generally، data from four adjacent stations are used for regenerating the missing data at a particular station. In this research، fuzzy regression efficiency is employed for reconstructing yearly rainfall data in Karoon basin. The results are compared with methods such as normal ratio، graphical، simple linear regression and multivariate linear regression. Reconstruction groups were formed using the clustering method in minitab software. Twenty-five stations، similar in their duration of data collection، were selected from among stations in the northern Karoon basin and these were classified into 5 clusters. Following data elimination by cross validation، their value was estimated using the above mentioned methods. Then، using the root mean square of errors (RMSE)، the priority was evaluated for each method. The results of yearly data regeneration indicate that fuzzy regression yielded more accurate estimates in 12 out of the 25 stations studied، or in 3 clusters out of the 5 classified group، making it the most appropriate method for regenerating data for the whole of Karoon basin.

Models can be calibrated using suitable field data. A coupled volume balance–zero inertia (VB-ZI) model increases the accuracy of advance distance estimation in furrow irrigation. Surface storage volume in VB-ZI model was estimated using a power function. In this research the subsurface storage in furrow irrigation was calculated using the corrected Hall technique and a modified VB-ZI model (MVB-ZI) was developed. The developed model uses the momentum term of the ZI model. For evaluation of the MVB-ZI accuracy in furrow irrigation, three data series in different field conditions were used. The collected field data were hydraulics and geometric coefficients of cross section, advance time, inflow and outflow discharge, Manning’s coefficient, furrow bed slope and infiltration coefficients. The root mean squared error (RMSE) index, coefficient of residual mass (CRM) index and model efficiency (ME) index were used to evaluate the model. The RMSE values for the MVB-ZI model were 26.57, 12.71 and 20.49 for data series 1, 2 and 3, respectively. The calculated values for VB-ZI model were 30.13, 16.63 and 22.48. The CRM values for field data series 1, 2 and 3 were 0.217, 0.272 and 0.303, respectively which indicate the MVB-ZI model overestimation. The results show that the MVB-ZI model accuracy in estimating advance distance in furrow irrigation is greater than that of the VB-ZI and VB models. Therefore, the use of MVB-ZI model is recammended because of its simplicity and accuracy compared with VB-ZI and VB models.