Iranian Journal of Irrigation and Drainage
Year:2021 | Volume:15 | Issue:1|Papers Count:20

The aim of this study was to investigate the possibility of using lead contaminated water in surface irrigation and subirrigation and its effect on silage maize yield. In this regard, lysimeter experiments were conducted in the College of Agriculture and Natural Resources, University of Tehran in 2017 in the form of factorial experiment in a completely randomized design with six treatments in three replications and a total of 18 experimental plots. Treatments included: Surface irrigation with lead-contaminated water (SP), Surface irrigation with fresh water as control treatment (SC), Subirrigation with lead-contaminated water and water table depth of 50 cm (50P), Subirrigation with fresh water and water table depth of 50 cm (50C), Subirrigation with lead-contaminated water and water table depth of 75 cm (75P), and finally, Subirrigation with fresh water and water table depth of 75 cm (75C). The results showed that the effect of irrigation management on plant height, plant dry weight and maize silage yield at 1% probability level, wet plant weight and maize wet weight at 5% level was significant and it had no effect on maize dry weight. Also, pollution had no effect on growth and yield and components of maize yield. The results also showed there was a 2. 25 mg of lead per one kg of maize dry matter in the SP treatment, which this amount is in the group of low pollution according to the World Health Organization (WHO), No lead was observed in the plant samples of the 50P and 75P treatments. On the other hand, the highest maize yield was recorded in the 75P treatment with 49. 65 t/ha and then in the 50P treatment with 47. 04 t/ha. Crop yield increased by 36% and 29% in the 75P and 50P treatments compared to the control treatment, respectively. It is noteworthy that the amount of lead metal stabilized and rised in the subirrigation treatment was out of reach of the plant and there was no problem in terms of pollution and maize yield.

Surface water resource planning requires the estimation of water balance components at different spatial and temporal scales. Moreover, due to the inadequacy of the stations in terms of number, dispersion, and temporal data recording, numerical modeling of the land surface is necessary. In this study, the Noah-MP model was used to compare the simulated runoff by SIMTOP and BATS schemes and to evaluate the dynamic vegetation scheme for estimating actual evapotranspiration in the Neishaboor watershed monthly scale in 2000-2009. Due to the low accuracy and dispersion of hydrometric stations, the SWAT model output was used for evaluation. To develop the model, first, the sensitivity analysis of the modeled runoff to parameters of the model was performed. The model showed the highest and least sensitivity to the soil parameter in the Clapp-Hornberger relation (b) and runoff decay factor (f), respectively. The best and the first performance of simulated runoff by BATS scheme were in mountainous areas and the evaluation criteria including R2, NSE, and RMSE were respectively 0. 81, 0. 64, and 1. 91. The second grade of performance was for the plain and the lowest values for simulated runoff were in foothills regions. Results indicate that the BATS scheme shows better results in the plain and foothills areas and the results of the SIMTOP scheme in the mountainous regions were similar to BATS results. The dynamic vegetation scheme has been able to simulate evapotranspiration changes along with the stages of plant growth. The mean of annual evapotranspiration estimated by the Noah-MP model was 305 mm.

In this study, MODFLOW and MT3DMS codes were used to evaluate changes in groundwater quality in Neyshabour plain under different scenarios. During developing the conceptual model, it was found that the aquifer salinity increased due to the presence of fine alluvium and evaporite minerals in the margins of the plain and agricultural return flow. Groundwater models was calibrated under transient condition for 10 years from October 2001 to September 2011 and validated for a 4-year period (October 2011 to September 2015). Quantitative comparison of the head and Cl data in all the observation points indicated a reasonable match between the observed and the calculated values. The root mean squared error (RMSE) was 1. 92 m and 1. 65 m for the calibration and validation periods in the flow model, and the RMSE was 2 mg/l for the mass transport model in Neyshabour aquifer. The MODFLOW and MT3DMS models were used to simulate the effect of the two scenarios: (1) continue the current trend in groundwater withdrawals and (2) 40% reduction in groundwater withdrawals has been examined by the model. In the first scenario, the average groundwater level showed annual loss of 0. 79 m and increasing in the groundwater salinity. Under the second scenario, which aimed to achieve equilibrium status in the groundwater balance, pumping rate for all wells were reduced by 40%. The results showed that although the average water level in the aquifer does not decrease, the groundwater salinity is still increasing, with a rate of 50% lower than in comparison to the first scenario. This reflects the fact that reduced groundwater withdrawals at the same rate for all wells may not meet water resource management goals and groundwater management requires distributed information about the aquifer.

The scales of temporal and spatial steps of Atmosphere General Circulation Models GCM are continental and global. Therefore, it is necessary the models act on the local behavior of the station data, to understand the status of a local station using these models. In this study using SDSM, LARS_WG models and artificial neural network method Based on observational data obtained from 6 synoptic stations in Isfahan province, temperature and precipitation forecasts of these stations from 2021 to 2050 have been investigated. Pearson's correlation coefficient (r) and coefficient of determination (R2) between observational data and scenario data at all stations are above 0. 6, and root-mean-square error (RMSE) is acceptable, then good simulation has been performed. Based on the results, the temperature of Isfahan province increased from 2021 to 2050 and based on SDSM, In 2005 it had the lowest value and in 2050 it had the highest value And the temperature difference of these years is about 2/3 °,C, which indicates that the temperature will rise and Precipitation changes are almost similar to current changes and We will have the highest amount of precipitation in 1405 and 1406 which, in daran statian which, It has more rainfall than other stations, it will be about 2. 3 mm.

It has been documented that the assumption of capillary movement of water in a bundle of cylindrical tubes often leads to systematically underestimation of soil unsaturated hydraulic conductivity at low potentials which is due to ignoring the contribution of adsorptive forces and liquid films. In this study, the performance of two physical models of (Tuller-Or) and (Lebeau-Konrad) that take into account the contribution of both adsorptive and capillary forces and the well-known capillary-based model of (Van Genuchten-Mualem) for modeling the soil-water retention curve and estimation of the unsaturated hydraulic conductivity were evaluated. To that end, experimental data gathered from literature including six soils that cover a broad range of texture and hydraulic behavior. The results showed the superiority of the two capillary-adsorption models over the capillary-based Van Genuchten-Mualem model in estimating the soil-water characteristic curve and unsaturated hydraulic conductivity. Among the two physically capillary-adsorption based models, the Lebeau-Konrad model performed better. The results showed that the Lebeau-Konrad model underestimates the hydraulic conductivity of clayey soils in the near saturation range and the best performance of the Tuller-Or model was shown to be for loamy soils. Because the Tuller-Or model is the most comprehensive and physics-based model for modeling the unsaturated hydraulic conductivity up to date, future studies should be devoted to improving the flexibility of this model via extending the model to other pore size distribution than the original Gamma distribution, such as lognormal, incomplete gamma and Weibull distributions.

The combined weir-gate is important hydraulic structure in management of irrigation canals. On the other hand, the use of labyrinth weirs can reduce water level fluctuations due to longer crest lengths than linear weirs for a specific discharge. Because of the sediments deposition in upstream of the weirs the flow conditions change and the accuracy of the presented relationship is reduced. Therefore, the use of combined flow trapezoidal labyrinth weir-gate can be a useful solution for passage of floating substances over the weir and sediment transport under the gate. In this research, experimental study of combined flow trapezoidal labyrinth weir-gate with one cycle has done for three sidewall angles of 15, 20 and 25 degrees, three gate openings 2, 4 and 6 cm and three weir heights of 14, 17 and 20 cm in a rectangular channel. Based on the effective parameters of the combined models, the mean discharge coefficient has obtained in the range of 0. 61-0. 75. The results show that the discharge coefficient decreases with increasing the ratio of Ht/P, and it reaches a constant discharge coefficient of 0. 61 for Ht/P >0. 6. The discharge coefficient of the combined model increases by increasing the angle of weir. Also the results show that the discharge coefficient of trapezoidal labyrinth weir-gate has the highest value for weirs with a sidewall angle of 25 °,and gate opening of 2 cm.

In the current experimental study, economic analysis of deficit irrigation was conducted for an orange orchard and results were evaluated based on the highests net income. This experiment was performed as a split plot in the form of a randomized complete block design with five replications in 2018. The main treatments were two types of irrigation management including variable irrigation interval and 4 days irrigation interval. Sub factor was 4 irrigation levels including 100%, 80%, 65% and 50% of soil readily available water (RAW). For economic evaluation, production, cost and income functions and optimum water use depths were calculated using English method. Results showed that irrigation water depth for maximum yield for two types of irrigation management was 148. 3 and 186. 5 mm, respectively. When land is limiting, the best irrigation water depths were 146. 2 mm and 184. 0 mm. When water is limiting, the irrigation water depths are 109. 3 and 136. 9 mm, respectively, which caused more than 16percent increase in net income per unit volume of water both two types of irrigation managements. With this amount of saved water, if land is not limited, the cultivated area can be increased up to 36% and 36%. Results showed that the optimum irrigation water management (in unlimited conditions) is 4 days irrigation interval and 80%RAW irrigation depth. For this situation, the yield was 55 ton/ha. The net income for this case is more than 483 million Rials per hectare and B/C equals to 1. 78. The highest net income (for no land limitation and irrigation depth equivalent to full irrigation), is irrigation as large as Ww (water limitation conditions) that net income for the without and 4 days irrigation interval are more than 476 and 611 million Rials, respectively. This case generates the most net income per unit volume of used water. Results showed that in both unlimited condition and in water limitation condition, having an irrigation schedule and also applying deficit irrigation has a positive effect on the gardener's income that for deficit irrigation in unlimited condition 1492 and in water limitation condition 1369 m3/ha water is needed.

Water is the most important limiting factor for agriculture and its optimal use with special importance. The purpose of this study was investigating of the effect of different irrigation methods on yield and yield components of wheat (Pishtaz cultivar) and evaluate of water efficiency. The following treatments included three methods of surface, sprinkler and strip drip irrigation. The experiment was conducted in a randomized complete block design with three replications in 2018_2019 in Khorramabad city. The research results demonstrated that type of irrigation method had a significant effect (p < 0. 01) on the number of spikes, number of seeds per spike, stem height, 1000-seed weight, grain yield and water efficiency. Grain yield in surface, sprinkler and drip irrigation methods were 7. 870, 6. 83 and 5. 017 tons per hectare, respectively, in other words, surface irrigation increased grain yield by 13. 21 and 36. 25 percent compared to sprinkler and drip irrigation methods, respectively. Also, the highest volume of applied water (6411 m3) and the lowest water efficiency (1. 22 m3) were related to surface irrigation treatment. Strip drip irrigation treatment with about 3333 m3 of water irrigation, saved 59% of water compared with surface irrigation and therefore.

In the northeastern regions of the country, due to climatic conditions as well as severe water shortages, it is necessary to cultivate crops that have low water requirements and at the same time have optimal water efficiency. This research randomized complete block design study was performed with two factors of irrigation system type (surface S1 and subsurface S2) and irrigation time (region custom or mehr (October) 15 T1, 15 days delay T2 and 30 days delay T3) and three repetitions. The results of the mean squares showed that the quantitative traits (number of flowers, fresh flower weight, dry stigma weight, dry cream weight and large flower index) of saffron due to the interaction of irrigation method and time of first time irrigation were insignificant and only dry cream weight trait was significant at probability 5% level. The results of the mean squares of qualitative traits (piroxin, crocin, safranal, moisture, mold, and total microorganisms) of saffron in the irrigation time factor and the contrast of irrigation time factor in the irrigation system type of all qualitative traits were no significant. The results showed that the highest value for quantitative traits was the number of flowers and the dry weight of stigmas for S1T2 treatment with 53. 1 flowers per square meter and 0. 79 grams per square meter, respectively. Also, for qualitative traits of piroxin, crocin, saffron and microorganisms, the total S2T1 treatment was obtained with the values of 1/92, 1/262, 1/33 (maximum absorption) and 10733 numbers per gram, respectively and the best irrigation method and Irrigation time, surface system and 15 days delay were obtained.

Prediction of flow discharge coefficient of gates is one of the essential issues in water engineering sciences. In recent years, various semi-empirical equations have been developed in order to predict the discharge coefficient of radial gates that the application of these formulas under submerged flow conditions suffered from large errors. The aim of present study is to apply robust Gaussian Process Regression (GPR) and Support Vector Machine (SVM) to predict discharge coefficient of radial gates under submerged flow conditions and compare the obtained results with well-known semi-empirical approaches. For this purpose, an extensive experimental dataset comprises 2136 data points were used to feed the utilized methods. Different combinations of dimensionless parameters were prepared and the performance of aforementioned methods were assessed. The obtained results showed that GPR method with input parameters of y0-yt/w and yt/w yields a correlation coefficient (R) of 0. 983, a Nash-Sutcliffe efficiency (NSE) of 0. 967 and root mean squared error (RMSE) of 0. 027 and indicated superior performance compared with employed SVM and other semi-empirical approaches.

The purpose of the present study was Investigating of Climate Change Effects on the Surface Runoff of the Mazlaghan area For this purpose, SWAT model was used to simulate basin hydrological regime and SUFI-2 algorithm in SWAT-CUP software to optimize model parameters. Statistical data used for runoff simulation were years (1997-2015). To evaluate the ability of SWAT model to simulate runoff discharge, Nash Sutcliffe, R2, p-factor and r-factor indices were used. Using the LARS-WG climate change model in the study area, map the observational data of Razin Station with long-term climate data, taking into account RCP2. 6, RCP4. 5 and RCP8. 5 climate change scenarios for the coming period 2021-2040 Climate change in the region was evaluated. . LARS-WG model to ensure the correct calibration errors indices of average root mean square error (RMSE), mean absolute error (MAE) and the coefficient of productivity Nash Sutcliffe (NSE) was used,The results of the study, while confirming the efficiency of the model, showed for the period 2021-2040, an increase in the mean annual temperature will occur based on the three scenarios mentioned. Also, the average monthly rainfall under the scenarios of RCP2. 6, RCP4. 5 increases and RCP8. 5 predicts a decrease. Finally, according to the predicted climatic data in runoff simulation, an increase in runoff is predicted in the Alluvial Basin.

Saturated hydraulic conductivity is one of the main parameters in agricultural and environmental studies that is essential for the estimation and management of water and solute transport in soil. In this research, 1200 series of data related to loamy soils were used to prediction and modeling saturated hydraulic conductivity using soil physical properties such as bulk density, available water capacity, organic carbon content and percent of clay, silt and sand content. From studied data series, 900 series were allocated for use in training models and 300 series for testing models in three designed scenarios. The performance of SVM, MLP and M5 models was evaluated in estimating saturated hydraulic conductivity of loamy soils. The performance of the models was compared using the statistical indices such as coefficient of determination (R2), root mean square error (RMSE) and mean bias error (MBE). The results showed that all three models used have good ability in saturated hydraulic conductivity modeling, but the M5 model with a high coefficient of determination over 0. 95 in all three scenarios and a lower RMSE than other models was selected as the superior model. The results showed that intelligent data mining models make it possible to estimate unknown values based on ready patterns in a database. Therefore, the applied models can be used to predict solute transport in soil and soil physical parameters.

The purpose of the present study was to determine the flood Routing kinematics of the Ghareh-chay River that is done in the MATLAB programming environment. By providing the required data, the flood flow routing modeling of each station was performed by the kinematic wave method in the Ghareh-chay River basin. The results of physical characteristics of the river indicated that the study area had low slope and roughness coefficient and high soil curve number. In order to improve the kinematic wave routing, modeling was performed with input hydrograph as the initial condition and considering zero value for all zero-second discharges as the boundary condition. The obtained graphs show the conformity of the modeling performed with the observed data. Nash–, Sutcliffe (NS), Coefficient of Determination (R2) and Normal Root Mean Square Error (NRMSE) indices were used to evaluate the model capability. In the results of the model performance evaluation for the Hydrometric Azna, Bazaneh, Toure and Pole Doab with the high value of Nash coefficient and Coefficient of Determination and the low error value of NRMS indicate that the model The kinematic wave has been successful in simulating flood flow and has good accuracy, and it was determined that the results of the present model can be generalized to basins with this type of shape.

The present study was conducted to provide sustainable solutions in water resources management using the concept of water footprint and water use efficiency of barley at the national level. At the beginning of the study, the provinces of the country were classified according to the Dumartin climate. Then, green, blue, gray and white water footprints in barley production and water use efficiency in different climates and provincial centers were calculated during the statistical period of 2008-2017. Also, spatial and temporal zoning of water footprint and water use efficiency were performed. The results showed that the highest water footprint of green water in the humid and Mediterranean climate of the north of the country were Rasht stations (592. 553 m3/ton), Gorgan (570. 86 m3/ton) and Sari (543. 53 m3/ton) and the lowest In ultra-dry climate, Yazd station was obtained with 124. 21 m3/ton. Zahedan station with ultra-dry climate had the highest water footprint of blue (787. 01 m3/ton) and Rasht with humid climate had the lowest (86. 73 m3/ton). The highest amount of gray water footprint was related to Zahedan stations (390. 4 m3/ton) and Bushehr (390. 11 m3/ton) and the lowest amount was in Hamedan station (239. 67 m3/ton). In terms of white water footprint, the highest was in Zahedan station (1956. 2 m3/ton) and the lowest was in Rasht station (515. 599 m3/ton). Spatial distribution of total water footprint showed that the highest total water footprint was in the southeast of the country and the arid climate and the lowest was observed in the northern and western parts of the country. The results of water use efficiency zoning showed that the highest water use efficiency was observed in the western regions of the country and the lowest was observed in the northern and western parts of the country. Therefore, according to the obtained results, it can be said that the northern and western regions of the country are more suitable for planting barley. Also, due to the lack of water in areas with dry climate and high water footprint in these areas, barley cultivation in these areas should be avoided. In these areas, cultivation of crops with less water requirements and higher yields should be planned. Barley cultivation in these areas is due to the high tolerance of barley to salinity and low soil fertility. Therefore, it is necessary for the authorities in these areas to plan the cultivation of crops with lower water requirements and higher yields and tolerance to salinity to replace barley.

Today, due to high water consumption in the agricultural sector and the water crisis in the country, efforts have been made to improve irrigation methods. Given that agricultural irrigation is still superficial, it is necessary to find a solution to improve these methods at a much lower cost than pressurized irrigation. The purpose of this study is to use SIRMOD software to determine the optimal values of design parameters such as length, flow and cut-off time in two continuous flow regimes and flow reduction in strip and stream irrigation systems. Using the SIRMOD model, 25 and 50% of the actual values of field length, inlet flow and cut-off time were generated. The results showed that with a reduction of 25 to 50% in the length and flow rate to the farm, evaluation indicators such as application efficiency, storage efficiency, distribution uniformity, increase significantly And runoff ratio and deep penetration ratio were significantly reduced. The results of the effect of changes in tape length on evaluation indicators show that the amount of storage efficiency in the range (-0. 5 to +0. 25) is almost a constant value equal to 100, but in the range (+0. 25 to +0. 5) The efficiency has changed even in some places to 80, and the application efficiency in most furrows is a value between (90 to 40). The results showed that the flow reduction method, while being effective in increasing the evaluation indicators due to the interruption of water flow by the farmer after the end of the progress phase, especially in strip irrigation, did not have a significant effect on increasing the indicators.

Increasing the water productivity by cropping pattern optimization is one of the best ways for development in agriculture. In this study, in order to maximize farmers' income and minimize blue water footprint of wheat, barley, alfalfa, and maize, the NSGA-II multi-objective optimization algorithm and United Nations commission on sustainable development’, s indicator has been used in four cropping pattern scenarios in the 56 cities of the eastern provinces of Iran. The results showed that in some scenarios it was not possible to fully achieve these goals in the multi-objective model. The results also showed that the production of 50, 75 and 100% of the current values causes a low, moderate and severe water stress in the study region, that on average, save 55, 40 and 30 % of the region's water resources, respectively. Implementation of this model in the study area would increase revenue, reduce water consumption and, consequently make more environmental sustainability.

The development of water waves through submerged and non-submerged vegetation is accompanied by a loss of energy through the resistive force of the vegetation, resulting in a decrease in wave height. Wave damping by vegetation is a function of cover characteristics such as geometry and structure, immersion ratio, density, hardness, and spatial arrangement, as well as wave conditions such as input wave height, duration, and wave direction. In the present study, the effect of geometric arrangement of vegetation with variable height on wave damping has been investigated using the Flow 3D numerical model. For this purpose, a channel with a length of 480 cm and a width of 10. 8 cm, which has been previously used by Cox and Wu (2015) to study the effect of plant density with variable height on wave damping, is modeled. The operation of the three arrangements, including long to short arrangement, short to long arrangement, and zigzag arrangement, is examined under four different waves, all of which are linear waves. It should be noted that in this study, wave height is considered as a damping index. The results obtained by measuring the height of the waves at four different points along the channel show that the behavior of the waves in dealing with different arrangements follows a fixed pattern and also changes in the geometry of the vegetation can greatly lead to Increase the damping of the waves. The results show that a change in height arrangement can cause a change in damping of up to 7. 1%.

Scouring is one of the most important factors threatening the stability of bridge abutments on rivers. Most of bridge abutments are located in floodplains. In the present study, the effects of four different single spur dike shapes including the simple spur dike, T-shaped spur dike, L-shaped spur dike with a clapper toward downstream, and L-shaped dike with a clapper toward upstream on the maximum scour depth at the abutment of a bridge, are studied. The present study was conducted on a rectangular flume with a width of 1m, a length of 12m, and a height of 60cm. The compound channel was constructed in a symmetrical and rectangular shape with the width of the main channel 20 cm and the width of the floodplains 40 cm. Spur dikes with three lengths including the 4, 8, and 12-cm lengths were installed as single spur dikes at 4, 8, 12, 16, 20, 24, 28 and 32-cm distances from the abutment. The results indicated that the simple spur dike, the T-shaped spur dike, the Lshaped spur dike with a clapper toward downstream and the L-shaped spur dike with a clapper toward upstream reduced the maximum scour depth at the abutment by 80%, 93%, 96% and 78% respectively.

The investigation of plant production limiting factors requires extensive and costly research, so the use of models can be noteworthy. Practical models including Aquacrop and DSSAT are used to simulate plant production. In the first year, these models were calibrated for Khuzestan wheat farms in Ramseh pilot and in the second year for two pilots, Ramseh and Hamidiyeh. The normalized root mean square error, agreement index and model efficiency with DSSAT model for grain yield values in the first year were 0. 036, 0. 01, 0. 92 and 0. 76, respectively that Comparison of these values with statistical indices obtained from Aquacrop model indicates less error and more performance index for using DSSAT model. Also, the performance of the model, which is an indicator of the effectiveness in the selection of models, shows that the DSSAT is more efficient than the Aquacrop model. Mean root mean square error and normalized root mean square error of wheat biomass in the DSSAT model were determined to be 0. 23 and 0. 04 respectively that indicates the DSSAT model has higher efficiency and accuracy than the Aquacrop model in simulating grain yield and wheat biomass.

Among the indicators of optimizing water consumption in the agricultural sector,crop water productivity index has received more attention. This index is estimated based on the crop yield and water requirement, which depends on meteorological parameters, soil characteristics, field management and crop type. Due to changes in meteorological parameters in different regions, changes in the crop yield and water requirement in different regions can be expected. In this study, the Maize SC 706 was cultivated in the research farm of faculty of agriculture, Razi University, Kermanshah, in a randomized complete block design with treatments of 120, 100, 80 and 60% of irrigation requirement and three replications. The AquaCrop model was calibrated and validated using measured farm data. The results of model output and field data showed that the difference between biomass yield and grain yield in irrigation treatments was significant at the level of one percent. According to the calibrated crop file and daily meteorological data (1988-2017), water requirement and grain yield under full irrigation conditions in five synoptic stations of Kermanshah, Islam Abad Gharb, Sarpol-e Zahab, Ravansar and Kangavar were estimated using the model. The average of grain yield for the 30 years studied in these stations was estimated at 9403, 9261, 9171, 9016 and 9151 kg / ha, respectively. According to the estimated yield and water requirement, the amount of water productivity in the full irrigation conditions was calculated, the amount of which for Kermanshah, Islamabad Gharb, Sarpol Zahab, Ravansar and Kangavar stations respectively were 0. 95, 1. 09, 1. 09, 0. 88 and 1. 18 kg of grain per cubic meter of water were estimated.