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This paper aims for evaluating the border irrigation performance sensitivity including application efficiency, advance time, runoff and deep infiltration ratios to the variation of soil texture, land use, discharge, border length and soil moisture. The measurement of infiltration was done by the double-ring method in five soil texture classes and three land uses. HYDRUS-1D model was calibrated for simulating infiltration in various initial soil moisture. Next, calculated infiltration parameters by HYDRUS-1D were presented to SIRMOD for simulating border irrigation in the various lengths of the border and discharges. The result showed by decreasing the soil moisture, the variation of the performance parameters has possessed a trend of increasing, but for the runoff ratio. Therefore, by incrementing the irrigation period, application efficiency will be incremented. Under different soil textures and land uses, the deep infiltration and runoff ratios were the most and least sensitive parameters concerning soil moisture. Most variations of performance parameters were in sandy loam texture and wheat land use, however, the least variations of the parameters were in silty loam texture and fallow land use. To decrease application efficiency sensitivity to soil moisture, discharge and border length must be considered less and more for soils with great permeability than for soils with little permeability, respectively.

Groundwater resources are increasingly exposed to significant overexploitation in many parts of the world, markedly in Iran, one of the most arid areas. Social, economic and environmental aspects including water quality and quantity concerns are necessary for sustainable management of water resources. The aim of the current study was to investigate the changes in groundwater levels and quality in the Isfahan-Borkhar aquifer. Groundwater fluctuation contour lines maps provided in Geographic Information System (GIS) during 1971–2005 in this area indicate that excessive extraction of wells has led to major decline in water levels and a marked increase in concentration of Total Dissolved Solids (TDS). The Groundwater Modeling System, a three-dimensional MODFLOW model paired with MT3D, was utilized to survey the aquifer characterization in the area. In the first step, usage high amount of hydrological and geological data, the conceptual model was developed and calibrated in both steady and transient states. The results of the calibration showed that the error between calculated and observed levels was in optimal level. Subsequently, since rainfall is decreasing annually in the study area and the aquifer is in danger of drought, and uncontrolled exploitation of wells has led it to a crisis, two scenarios were considered to simulate quantity changes in the aquifer: Simulation in drought and rainfall reduction. The results indicate that during both the drought period and increasing exploiting from the pumping wells, the level of water has fallen 0.5–0.1 m/s annually, and it will destroy the aquifer. Finally, the calculated hydraulic heads and velocity of flow of groundwater in the aquifer are recovered in the mass transport modelling package MT3D to find the concentration of TDS in the groundwater. Simulation results indicate that concentration of TDS is with far more amount in the areas around the lake located in central parts due to evaporation of Borkhar-Isfahan Aquifer and geological structure of the region. Scenarios considered for prediction by transport model show that concentration of TDS would enhance if the current situation continues; however, this is mainly influenced by hydrology and geology of the area.

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.

Salinity and sodicity problems are ubiquitous in dryland and irrigated systems, and research into possible amendments to remediate soils in these systems is needed. This study was conducted to investigate the effects of organic and inorganic amendments on spring wheat (Triticum aestivum UG99) yield and salts redistribution within the profile of a repacked saline–sodic silt loam soil (ECe = 12.9 dS m−1, exchangeable sodium percent (ESP) = 17.6% for control). The experimental design for greenhouse study was completely random with two factors (amendment and leaching fraction, LF). The amendments included biochar (2%) [B], biochar + manure (2%) [BM], zeolite modified with CaCl2 (2%) [ZC], super absorbent (1%) [SA], and a control (no amendment) considering two levels of LF (15 and 30%). All amendments, except ZC, decreased soil bulk density and electrical conductivity, and increased soil pH and water content at field capacity after 2 pore volumes leaching. There was positive effect (p + and Mg2+ concentration in straw, while K+ concentration increased; resulting in reductions in the Na+/K+ ratio. In general, the study showed that B, BM and SA are suitable amendments for increasing yield by improving soil conditions and reducing salts and Na+ accumulation in plants.

One of the most methods for design of surface irrigation is volume balance model. This model assumed that the shape factors are constant. This assumption causes significant errors in computations. In this paper were investigated the variations of the shape factors relative to time by Valiantzas’ method. This method is based on combination of volume balance and kinematic wave models. Results of the method as advance curve had a good agreement with field data. So the method proved that subsurface shape factor was variable relative to time and all its values were more than its constant value in initial volume balance method. The variation of surface shape factor was less than the other factor.

Wetting pattern in a trickle irrigation system is one of the most important characteristics that should be taken into consideration for designing the irrigation systems. Improving the dimensions of the wetting pattern will increase the water use efficiency and irrigation systems. The objective of this study was to investigate the effect of rice husk and its biochar application on the wetting pattern in a silty clay soil under surface trickle irrigation. A box with the length of 200, the width of 50 and the height of 100 cm was used. To easily fill and empty the model, it was filled up to a height of 50 cm. The rice husk and its biochar were added to the soil at the rates of 0, 1 and 2 mass percentages based on a factorial arrangement of the treatments in a completely randomized design with three replications. Biochar was prepared in a special furnace at 500°C without oxygen. The experiments were done with a flow rate of 4 liters per hour with the irrigation time of 3 hours. The results of the analysis of variance showed that the organic treatments increased the soil water content in the range of field capacity to a permanent wilting point; the highest increase was observed for the biochar 2% treated soil. Also, the addition of rice husk and biochar in the silty clay soil reduced the horizontal advance and increased the vertical advance wetting pattern.

Nowadays, environmental pollutions especially water pollution is increasingly developing. One of the problems of entering the pollutants to rivers is reduction in the concentration of river dissolved oxygen. In order to manage the water resources, amount of dissolved oxygen should be predicted. This study presents a novel equation for simulating the concentration of river dissolved oxygen by adding the oxygen production and consumption in the river factors to equation for transmission-diffusion of minerals in the soil. The resultant equation was separated in finite differential method and by using implicit pattern. Calculations were done by encodings in MATLAB software. In order to calibrate and confirm the dissolved oxygen model, data derived from Zayanderood River around Zob-Ahan factory of Isfahan and Mobarakeh Steel Complex was used. By using some data, coefficients of model were determined. Analyzing the sensitivity of model coefficients showed that aeration constant (Kr) had the most effect on predicting the model. Since depends on hydraulic parameters of river, sensitivity of depth and pace of river was studied and finally depth of river was introduced as the most sensitive variable.

One of the approaches for recycling and reusing agricultural and animal wastes is to pyrolyse the residues and subsequently use them as soil amendments. The prevalence of several feedstocks suggests that it is necessary to investigate the optimal combinations of feedstocks and pyrolysis temperature for use as soil amendments. This study was done to evaluate five combinations of raw materials (sugarcane bagasse, rice husk, cow manure and pine wood) and their biochars produced by slow pyrolysis at 300°C and 500°C for soil amendment. Several physicochemical properties (electrical conductivity (EC), pH, cation exchange capacity (CEC), total organic matter content (C) total porosity (TP), total nitrogen (N), particle density (PD) and bulk density (BD)) were investigated. Comparison among feedstocks showed that the highest PD, BD and CEC were observed in WM (cow manure-pine wood). The pyrolysis process increased the PD, TP, N and monovalent cations and decreased EC, CEC and BD. Compared to the feedstock, pyrolysis increased the N content, but higher temperatures lowered the N content. Pyrolysis at 500°C reduced the EC, N, CEC and biochar yield by 18%, 13%, 21% and 24% respectively, compared to 300°C. Pyrolysis at 500°C increased the pH, Na+ and K+ by 17%, 12% and 22%, respectively, compared to 300°C. Considering the physicochemical properties of biochar and the costs, the bagasse-wood-rice (BWR) combination and temperature of 300°C are suggested for biochar production for soil amendment.

Today, the use of refined urban wastewater for agriculture is growing considerably. One of the methods for the natural treatment of wastewater is the constructed wetland. In this study, the effects of three and six days retention time on the vertical, horizontal and hybrid constructed wetland (first vertical and then horizontal) with perlite beds and Cyperus plants on the urban wastewater were investigated. In this study, horizontal wetlands were designed with 0.75 m width, 0.5 m depth and 6 m length; the vertical wetlands were designed as cylinders with a diameter of 0.7 m and the height of 1.2 m. On average, for the three days retention time, in the wetland with the vertical flow, 5the horizontal flow and the hybrid wetland, nitrate was 31.0, 36.7 and 56.3 percent, ammonium was 7.6, 32.7 and 37.8 percent, and the fecal coliform was decreased by 53.3, 93.4 and 96.9 percent, respectively. Also, during the six days retention time in the wetland with the vertical flow, the horizontal flow and the hybrid wetland, nitrate was 45.7, 58.5 and 77.5 percent, ammonium was 16.8, 75.2 and 79.4 percent, and fecal coliform was decreased by 58.0, 97.5 and 99.0 percent, respectively. Overall, the results showed that constructed wetland with perlite beds and Cyperus plants had a good function in removing pollutants, especially fecal coliform.

In order to balance between financial and social constraints of water and respond to competing for water requirements, it is important to sustain and manage essential water systems. Therefore, this paper aims to evaluate sustainable water management in specific sectors: urban, agricultural, and environmental and addresses questions, such as (1) how is sustainable water management described and assessed? (2) what challenges occur in sustainable water development in different sectors? (3) which aspects/elements of sustainable water developments are important in agricultural and urban water management? and (4) how do different countries improve sustainable water management? Depending on the complexity of water systems, water users and sources of water, techniques for estimating performances of water management can be simple (such as indicator techniques) or complex (such as several models). The techniques are analyzed in this study. The findings from implementing sustainable water management suggest that all water users consider which source of water (e.g., usable and reusable) is more suitable to use. They also state that increasing agricultural water use efficiency can significantly reduce total water consumption, which can lead to global food security. In addition, results showed that the level of local infrastructure conditions and financial capabilities are more important in sustainable water management than is the level of regional development.

Saline-sodic soils commonly display a poor soil structure which is associated with the reduction in soil quality. Therefore, optimal management of soil and water salinity in saline-sodic soils shou...

Urban and industrial wastewaters are considered as the most contaminant of surface water. Entrance of these pollutants to the river reduces the concentration of dissolved oxygen and aquatic life will be threatened. So, one of the main qualitative characteristics of water resources management is the concentration of dissolved oxygen. The base of the developed model in this investigation is the convection- diffusion equation in soil. Terms of production and decay of dissolved oxygen were added to this equation. The final equation was discretized using the finite difference method with the implicit scheme. With applying the initial and boundary conditions, the equation set was solved by the Thomas algorithm. The calculations were done by programming in the MATLAB software. For the calibration and validation of the model, data obtained from two reaches of Zayanderoud River, including steel melt and Mobarakeh Steel factories, were used. The temporal and spatial variations of the dissolved oxygen were plotted and compared with the real data and the results of the MSP and CSP models. The results showed that the concentration of the dissolved oxygen could be well predicted through solving convection-diffusion equation with introducing two terms for the decay and production of oxygen. The comparison between the results of the model and two other models showed that the model led to better results in comparison to the MSP and CSP models.

This study was conducted in 2015 to estimate pistachio (Pistacia vera L.) water use in Marvast region, central Iran. Daily and seasonal pistachio actual evapotranspiration (ETa) was first estimated by running the surface energy balance algorithm for land (SEBAL) model, using 12 Landsat 8 satellite images and other ancillary data. Finally, SEBAL estimates of daily and seasonal water use over three experimental sites of pistachio orchards were compared against ones based on performing water balance analysis for the top 150 cm of the soil layer. For this purpose, a simple funnel-shaped device was made and used to collect the beneath rootzone drainage water and determine the leaching fraction (LF) as well as deep percolation at three scattered points across the sub-sections of each experimental site. The results reveal that the LF varies from 0.16 to 0.34, leading to deep percolation from 95.0 to 334.0 mm of the irrigation water. Eventually, the differences between ground-based and SEBAL-based pistachio ETa were 11% (ranged from 5.7 to 14.0%) and 10% (ranged from 7.1 to 16.4%) for daily and seasonal time scales, respectively. Based on the obtained results, more than 60% of Marvast pistachio orchards have seasonal water use of 410.0 to 680.0 mm (with the average of 594.3 mm), while the cumulative ETo and cumulative pistachio ETc of the same period were 1558.0 mm and 920.0 mm, respectively. In other words, Marvast pistachio trees extract less water from the soil compared with their potential water demands. This is due to the effect of salinity on reducing evapotranspiration rate as well as deficit irrigation of pistachio trees in the water scarce area of Marvast region. In any case, the difference between pistachio ETc and ETa is reflected in declination of the pistachio yield.

Due to the dry climate and limitation of fresh water resources, using fresh and salt water is a solution for crop production under salinity conditions. This study was conducted at Isfahan University of Technology as a randomized complete block design with three replications and five irrigation management treatments in 2014. The treatments included irrigation with saline water (with the salinity of 5 dS/m, based on the relative yield of 75%), irrigation with fresh water (municipal water), alternate irrigation (irrigation with saline water and the next irrigation with fresh water), conjunctive irrigation (half of irrigation with saline water and the other one with fresh water) and irrigation with fresh water to reach the raceme stage, and irrigation with saline water. The maximum wet yield, dry yield and grain yield were related to the fresh water treatment with 4.14, 2.45 and 0.588 kg/m2 and the minimum values were obtained for water their water treated with 1.34, 0.765 and 0.0957 kg/m2 respectively. The conjunctive treatment had the highest yield after fresh water treatment. The various statistical indices showed that this model could be used for sorghum in Isfahan. The determination coefficient for yield was 0.65.The priority of model for yield simulation was salt water at the last stage, alternate irrigation, saline water, conjunctive irrigation and fresh water treatments, respectively.

Climate change has major implications for a wide range of natural processes and phenomena, with precipitation patterns particularly sensitive to changes in atmospheric forcing. The arid and...

In this research, the effect of dry drainage on the distribution of soil water content and salinity were experimentally and numerically investigated for 84 days. In the experimental study, soil water content and salinity were measured at different soil depths and four times after planting. Numerical simulation was carried out with HYDRUS-2D which was calibrated and validated using measured data from the experimental study based on different assumptions. Results showed that dry drainage could not only control the soil water content of the irrigated area but also transfers large amounts of salts from this area to the fallow area. So that at the end of the experiment, soil surface salinity of the irrigated and fallow area increased up to 145% and 270% more than initial values, respectively. Based on statistical indices, the accuracy of HYDRUS-2D simulation was improved by considering differences between parameters of the irrigated and the fallow areas including soil hydraulic and solute transport parameters. Furthermore, this accuracy was increased due to the application of the multiplicativity approach for combining water and salinity stresses. In addition, two indices of variations, soil surface salinity percent and soil salinity ratio, are recommended as suitable criteria for determining salt scratching time from soil surface of the fallow area and ensuring the sustainability of the dry drainage system.

Simulation-optimization models are valuable tools for determining the optimal performance of systems. The main objective of this research was to develop and validate EDOSIM (Evaluation, Design, and Optimization of Surface Irrigation Model) as a simulation-optimization model for surface irrigation systems. For simulation, which consisted of the design or evaluation of basin, border and furrow irrigation, the Volume Balance model was used. For optimization, twenty meta-heuristic algorithms were applied. In this model, based on irrigation, the volume of infiltrated water to soil was calculated without having advance and recession data. The hydraulic objective function was used to minimize the linear combination of seven performance indicators. Regarding the optimization of the objective function, the functional, multi-dimensional, static, constraint, continuous, single-objective, and meta-heuristic optimizations were applied. Data obtained from fifteen experimental fields were used for the validation of simulation, algorithms parameters setting, and validation of optimization. Comparison of the simulation results of the EDOSIM model with those of the Hydrodynamic model of SIRMOD software showed the good performance of EDOSIM model and the proposed method for estimating the volume of infiltration with RMSE = 0.068, R2 = 0.988, CRM = 0.005 and NRMSE = 4.2%. The Shuffled Complex Evolution (SCE) algorithm was found to be the best algorithm for the optimization of fields; in all fields, the objective function was decreased (improved). Comparison of the objective function of the EDOSIM model with eight solvers of Optimization and Global Optimization Toolboxes of MATLAB software also revealed the superiority of the EDOSIM model for optimization.

Water shortage and excessive use of water resources in arid and semi-arid regions, such as Iran, highlights the importance of using treated wastewater, especially for the highly demanding agricultural sector. Constructed wetlands (CWs) are among green technologies that offer an efficient and cost-effective wastewater treatment. This study investigates the complementary treatment of effluent from the Fooladshahr wastewater treatment plant, Isfahan, Iran, using pilot-scale CWs with horizontal (H-CW) and horizontal-vertical flow (HV-CW). The performance of two substrates, pumice and gravel, and the effect of using plants (Phragmites australis) was compared. Maximum removal efficiencies of total suspended solids (TSS) and biochemical oxygen demand (BOD5) were observed in the case of unplanted and planted HV-CW with pumice bed, respectively. In the case of gravel bed, planted H-CWs demonstrated maximum chemical oxygen demand (COD) removal efficiency. The highest mean outflow concentrations for TSS, BOD5 and COD were obtained in unplanted H-CW with pumice bed, likely due to shorter retention times compared to HV-CWs, as well as due to the absence of plants providing the required physicochemical and biological conditions for high performance treatment. Phosphate (PO43−) removal efficiency demonstrated seasonal dependency, where the highest values were obtained in warm seasons. In the case of fecal coliforms (FC), no significant differences were observed between the studied HV-CWs during the whole study period. Based on our results, planted H-CW with gravel bed provided an optimum removal efficiency while requiring a smaller footprint and lower expenditure than HV-CWs. This study demonstrates the application of CWs as an affordable solution for treating domestic wastewater for various reuse application in developing countries with water crisis, such as Iran.

Considering water scarcity in Iran, application of deficit irrigation or water stress on some crops is inevitable. We need to provide appropriate design for deficit irrigation. Furrow irrigation management to obtain high efficiency and uniformity is difficult. Therefore, to investigate the variation of the input discharge, the cut-off time and furrow length that are effective on the efficiency and uniformity are very important. The purpose of this research is to provide a method for determining the optimum water use depth and optimizing furrow irrigation design in deficit irrigation conditions and finally comparing design characteristics under full irrigation conditions and deficit irrigation and comparison in different soil tissues. In order to achieve the objectives of this research, an experiment was conducted on forage corn in Shahrekord in a completely randomized block design with 7 treatments of different levels of irrigation in 3 replications. The costs and benefits functions were determined based on design variable and depth of applied water. The software Lingo was used to optimize the design variables (length of the furrow, the input discharge and cut-off time) and depth of applied water in deficit irrigation condition. The results showed that the highest net profit was obtained using 535 mm (equivalent to 79% of full irrigation) and 85 meters, 0.39 liter per second and 188 minutes, respectively, for the length of furrow, input discharge and cut-off time. The results of this design were compared to full irrigation of deferent soil textures. The results showed that an increase in the permeability of the soil caused length of furrow and the cut-off time to decrease, while the flow rate increases and depth of applied water or percent of deficit irrigation were constant.

Soil and water salinities are major environmental factors limiting the productivity of agricultural lands especially in arid and semi arid regions. To determine salinity threshold values and slope of the yield decrements for crops of wheat, barley and maize, SWAP model was study for an arid region located in Semnan Province (52◦25' N 35◦11' E), central part of Iran with area of 35000 ha including 94 villages belonged to irrigation network of Garmsar district. The data collected from the above 94 villages for years 1998 to 2007 were used to calibrate and simulate yield of wheat, barley and maize using the SWAP model. The irrigation water salinities of 2, 4, 6 and 8 dS m-1 were used and yield reductions versus soil saturation extracts were evaluated and salinity threshold values and slope of the yield reductions were determined for each of the above crops. The results showed that the SWAP model predict crop yields with good accuracy and the threshold values and slope of the yield reductions are site dependent. These values should be determined for each area in order to be able to plan better irrigation scheduling for arid regions which have soil and irrigation water salinities problems.

In this study, a new method was developed to calculate the infiltration coefficients in furrow irrigation with natural non-uniformity of longitudinal slope. For this purpose, 12 usual tilled furrows with 42 m length and 60 cm width were selected. Then, five irrigation events were carried out and the advance-recession and inflow-outflow data were collected. The parameters of the infiltration equation in power-polynomial form (Kostiakov–Lewis) were calculated using the volume-balance (VB) method and based on a power model as advance equation. The non-uniform longitudinal slope in furrows was purposefully made, so that the advance function should not to follow a usual power function, and the power of function to be more than one in some cases. Besides, in some irrigation events, the negative infiltration equation was obtained. Accordingly, from analysis of VB equation components, several modifications were incorporated in procedure of parameter estimation. Some of these modifications include fitting a quadratic function for advance data and calculating the flow cross-sectional area from maximum surface storage value. Volume of infiltrated water was calculated using this method in each irrigation, and compared with the measured volume based on the inflow and outflow hydrographs as a control. The results showed that using the presented method, the average error in computed infiltrated volumes was reduced to about 4%, which validates the application of the new method.

In the subsurface drainage system, there is a high potential for nitrate leaching, causing the pollution of both surface and ground water. In this research, a simple but comprehensive process-based model was developed for simulating the water flow and nitrogen dynamics. Processes considered in this model included all the important processes involved in nitrogen transformations, as well as nitrogen transport. Nitrogen transformation processes comprised fertilizer dissolution, nitrification, denitrification, ammonium volatilization, mineralization and immobilization. The nitrogen transport processes included nitrogen uptake by the plant, soil adsorption, upward flux, surface runoff losses and drain losses in the fields with the drainage network. For model evaluation, the measured data obtained from Imam agro-industrial Company, in Khuzestan, Iran, were used. Computed RMSE of the simulated water table, the drainage discharge rate, nitrate and ammonium concentration in drainage water were determined to be 14.58 cm,1.82 mm/day,1.73 mg/L and 0.48 mg/L, respectively. The results indicated a good agreement between the observed and simulated data. This model could be, therefore, used for fertilizer management, thereby reducing the concentration of nitrate and ammonium in the drainage water and helping to prevent the environmental pollution.

Excessive use of chemical fertilizers, especially nitrogen fertilizers to increase crop and improper purification, and delivery of municipal and industrial wastewater are proposed as factors that increase the amount of nitrate in groundwater in this area. Thus, investigation of nitrate contamination as one of the most important environmental problems in groundwater is necessary. In the present study, modeling and estimation of nitrate pollution in groundwater of marginal area of Zayandeh-rood River, Isfahan, Iran, was investigated using water quality and artificial neural networks. 100 wells (77 agriculture well, 13 drinking well and 10 gardens well) in the marginal area of Zayandeh-rood River, Isfahan, Iran were selected. MATLAB software and three-layer Perceptron network were used. The back-propagation learning rule and sigmoid activation function were applied for the training process. After frequent experiments, a network with one hidden layer and 19 neurons make the least error in the process of network training, testing and validation. ANN models can be applied for the investigation of water quality parameters.

Application of organic and inorganic amendments is an excellent technique for enhancing available water content in the soils. In this study, municipal waste compost containing three different amounts (i.e., 5%, 10%, and 15% on a wet weight basis) of natural and Mg-modified zeolites were added to a loamy sand soil improving soil water retention. During the plant growth period, the volume of drainage water (DW) and soil water content were measured after each irrigation event and every other day, respectively. HYDRUS-1D was used to simulate the following treatment effects on DW, soil water content distribution and evapotranspiration under corn cultivation: unamended soil (Ctrl), soil amended with compost without zeolite (SC) and soil amendment with composts containing natural zeolite- and Mg-modified zeolites (SCNZ and SCMZ, respectively). Cumulative drainage content was 35.68%, 16.41%, 11.74%, and 10.95% of total applied water in Ctrl, SC, SCNZ and SCMZ treatments, respectively. In the topsoil, the soil water content increased by 4.67%, 5.51% and 9.08% in SC, SCNZ, and SCMZ treatments, respectively as compared to Ctrl treatment. This indicates that water losses decreased in treatments containing zeolite (specially the modified form) relative to Ctrl and SC treatments. The HYDRUS-1D model was effective at simulating DW at different irrigation events (R2 = 0.95–0.99, NRMSE = 0.06–0.16). Simulated soil water content statistically matched those measured using a SM150 soil moisture sensor. Statistical measures (R2 = 0.57–0.92, NRMSE = 0.07–0.19) indicated a close match between measured and simulated soil water content. The SCNZ and SCMZ treatments decreased the hydraulic conductivity and DW value and increased the water content in the upper layer (where the compost applied).

In order to determine the height of the filter in heterogeneous Earth dam, three embankment models were provided in a flume laboratory, with the length of 4.2 m at the base of dam, the width of 60 cm and the height of 1 m and body slope 1H: 2V. In the first model, the fine-grained and coarse-grained soils were used in downstream and upstream of the dam crest respectively. In models 2 and 3 with cutting fine grained soil from the toe of the dam to the dam crest, vertical clay core was replaced. Index of a / L (a thickness of clay core and L is the length of base dam) was 1.7 and 1.10 in the second and third models, respectively. Seepage experiments in tree water height of 80 and 55 and 30 were performed.

The unsteady flow can be analysed by Saint-Venant equations. These equations can be solved by characteristics and finite difference methods. The Saint-Venant equations are changed into four complete differential equations in characteristics method and these equations are solved by drawing two characteristics lines. The Saint-Venant equations are changed into set nonlinear equations and are solved using Preissman scheme in finite difference method. This set of equation is changed into linear equation using Newton-Rafson method and can be solved using Sparce method. In this research, the results of the two method were compared and this was shown that: 1) these two methods can draw the surface profiles and flow hydrograph as well; 2) the finite difference method is more accurate than that one; 3) the mesh size in finite difference method can be larger than that one; 4) the difference between two methods are increased by increasing the time and distance.

The every-other furrow irrigation is one of the mothods of deficit irrigation in furrow irrigation system. In this research,a randomized complete block design with three irrigation treatment and four replication on potato was stablished inAgricultural Research Center,Shahrekord, Iran. The irrigation treatments were: normal furrow irrigation(N), fixedevery-other furrow irrigation(F) and alternative(variable) every-other furrow irrigation(V). The frequency of irrigationwas constant and depth of it was calculated by measurement of soil moisture deficit and the volume of irrigation waterwas measured by a volumetric counter. The water and soil quality was normal (EC less than 1 ds/m). The differentfertilizers were used. After harvesting, water use efficiency, starch and protein content were measaured for each plot.There was significant difference between water use efficiency under different treatments, so that, the F treatment hadthe most water use efficiency. The every-other furrow irrigation decreased the starch content significantly. The Vtreatment increased the starch content significantly related to F treatment. There was no significant difference betweenthe protein contents in the three treatments.