مجله آبیاری و زهکشی ایران
سال هجدهم شماره 1 (فروردین و اردیبهشت 1403)

With the development of localized irrigation in arid and semi-arid areas, the soil is more susceptible to salinization. The salt accumulation in the soil can reduce crop yields, destruction of plants and even resulting the soil uncultivable. In this research, flood leaching and trickle leaching methods (tape) were investigated in a pistachio orchard. Comparing with the flood method, the results showed that, the amount of leaching water used in the trickle method was reduced by 62.7% for the first leaching leading to a total reduction of 26.7%. In the flood leaching method, the entire surface of the farm is leached, while in the 6-row method water to be directly use in saline accumulation areas, which saves leaching water. Also, in the trickle and flood methods the uniformity coefficient of salinity distribution increased by 7% and 3% respectively. In the trickle method, the salt mass balance added due to irrigation can be removed with only one washing step, while in the flood method, the mass of leached salt is less than the mass of added salt. For orchards leaching with localized irrigation, it is recommended to apply more leaching water to salts accumulation areas and for improving the salts management effectiveness low-leaching rates applied alternately is recommended.

Due to the diversity and multiplicity of atmospheric general circulation models (GCM), it is not possible to use all of them in the estimation of climatic parameters. Undoubtedly, using the right model in climate simulations can improve the accuracy and certainty of the modeling. In this study, ACCESS-ESM1-5, GFDL-CM4, IITM-ESM, INM-CM4-8, IPSL-CM6A-LR, MPI-ESM1-2 and MRI-ESM2-0 from the CMIP6 was evaluated in Nekarood river basin by applying multi-criteria decision-making (MCDM) approaches including compromise programming (CP), cooperative game theory (CGT), the technique for order of preference by similarity to ideal solution (TOPSIS) and weighted average technique (WAT). Then the final ranks were determined based on the group decision making method (GDM). To check the quality of the estimated rainfall of GCMs in accordance with the observed rainfall, correlation coefficient (CC), normalized root mean square deviation (NRMSD), average absolute relative deviation (AARD), absolute normalized mean bias deviation (ANMBD) and skill score (SS) were used. The weight effect of the evaluation indices in each of the MCDMs was determined by the entropy technique. The results indicate that the CC has the highest effect in the ranking process of GCMs with a weighted importance of about 45%. Finally, the GFDL-CM4 with a net strength of 18 in the group decision-making method was recognized as the most appropriate GCM, simulating precipitation for this watershed.

In rivers, the combination of surface flow and subsurface flow generates Hyporheic flow in the porous environment beneath and surrounding the river. To quantify exchange rate between surface and subsurface water, it is crucial to estimate hydraulic conductivity between the two sources of water. In this study, hydraulic slope and hydraulic conductivity of river bottom sediments were estimated using a mini-piezometer and manometer. Physical experiments were conducted to investigate the impact of natural obstacles on the river path, specifically tree trunks at varying heights (30-60-90 cm), in the year 2022 and Tuskestan River in Gorgan. Piezometers were placed upstream and downstream of the tree trunks, and the resulting hydraulic head difference was assessed through numerical modeling using COMSOL software to simulate hyporheic flow. The study found a 91% correlation between piezometer observation data and numerical solution results, which facilitated further investigation into computational exchange flows. Based on this, the computational exchange flows from the numerical model were also investigated. The results indicated that the highest amount of equilibrium flow occurs in the case where the height of the tree trunk is 30 cm (the exchange flow is 3.96 times without the tree trunk).

Groundwater is one of the key sources of water on the surface of the earth, which is important in agriculture, industry and drinking, and is considered as the guarantor of life for the future generation. In this research, 227 data series related to meteorological and groundwater parameters of Saravan plain in Sistan and Baluchistan province were used to predict and estimate the groundwater level using intelligent machine learning models. Out of this number of data series, 159 series were allocated for use in model training and 68 series for model testing in designed scenarios. The performance of random forest and M5P models was evaluated in estimating the monthly mean groundwater level of Saravan Plain. The performance of the models was compared using statistical indices of correlation coefficient (R), root mean square error (RMSE) and mean bias error (MBE). The obtained results showed that both used models have a good ability to groundwater level modeling, but the M5P model with a higher correlation coefficient has fewer errors than the random forest model. The fourth scenario of the M5P model is selected as the best model among the scenarios of two models with correlation coefficient, MBE and RMSE values of 0.961, -0.0001 and 0.727 in the training section and 0.871, zero and 0.265 in the test section, respectively. It is suggested that the groundwater level of Saravan Plain be evaluated with other methods of artificial intelligence and machine learning, and compared with the present study.

Ensuring the health and sustainability of the environment is one of the secondary goals of hydraulic structures. Water pollution and the reduction of its quality are serious threats to the health of the earth and will turn rivers into channels for polluted industrial wastewater. Increasing the residence time of flow in rivers by constructing hydraulic structures such as gabion spur dikes can increase the self-purification capacity. In this research, a laboratory investigation of pollution transport using NaCl tracer material in a laboratory channel with a sediment bed with a medium diameter (D50) of 11.85 mm, thickness of 12 cm, and length of 12 meters in a different number of fine-grained or coarse-grained gabion spur dikes from 1 to 4 were performed. Analytical solutions of Advection-Dispersion equation (ADE), OTIS model, and solution of Transient Storage Model (TSM) were used for numerical simulation. Laboratory results showed that gabion spur dikes with fine-grained materials reduce the peak concentration of pollution (Cmax) compared to coarse-grained materials. The results showed that the gabion spur dikes in the flow path increase the residence time of the pollutant by increasing hyporheic exchanges. The advection-dispersion equation (ADE) has low accuracy in the simulations due to the lack of attention to the role of the storage zone exchanges, with a determination coefficient (R2) of 0.71 to 0.83. On the other hand, the OTIS model, which is based on the transient storage model (TSM), considering the role of the porous zones of spur dikes in the transient storage of solute, has high accuracy with a determination coefficient (R2) of 0.91 to 0.98. The estimated coefficients of longitudinal dispersion (Dx) and storage zone exchange (α) by the temporal moment analysis were evaluated lower than the estimates of OTIS model in most of the simulations.

This paper presents a novel technology for desilting dam reservoirs in a continuous and controlled manner. The proposed technology utilizes a suction system that incorporates two pumps: a dredge pump for removing and transporting sediments, and a high-pressure submersible pump for generating water jets to create turbulent flows in the bottom sediment layers. To evaluate the effectiveness of the proposed technology, local experiments were conducted in two cases: with the suction pump alone and with the addition of water jet flow. These experiments were conducted at the end of the reservoir of Zenouz Dam, which serves as a case study. The collected sediment mass was measured over time, and the resulting mass-time graphs revealed three distinct phases: ascending, descending, and constant. Based on the local conditions, soil properties and dredging system, the maximum sediment mass removal rates by the pump were 100 g/s for the case without water jet and ranged from 200 to 430 g/s for the case with water jet. Dimensional analysis was performed to determine the relationship between sediment yield and parameters such as sediment volumetric flow rate and sediment mass flow rate. The results showed that the variations of sediment discharge followed the same characteristic curves (discharge - height) of the pump. The average de-sedimentation efficiency was found to be 7-14% and 2-3% for the experimental pump modes with and without the jet flow, respectively. This indicates that the water jet flow has a significant influence on enhancing the de-sedimentation efficiency, and without it, the sediment removal would not be feasible.

Due to the lack of highquality water resources, in many cases there is no other choice but to use lowquality or unconventional water. The filtration method is an efficient method for removing pollutants. For compare the amount of water purification in vertical and horizontal filters, two models of vertical and horizontal filters were made in Department of Irrigation and Development Engineering, University of Tehran.Three absorbent layers including sand, zeolite and rice husk were used. The purification rate was measured for three solutions contaminated with nitrate, salinity and TSS of each solution at two different concentrations. For each concentration of contamination, two purified samples were taken at two times of 5 and 10 minutes to determine the purification process over time. t-test was used in SPSS software to compare the filtration rate of vertical and horizontal filter and to observe the significance of the difference in filtration rates. The results showed that the amount of nitrate purification with concentrations of 36.72 and 59.08 mg/liter and at times of 5 and 10 minutes, respectively, in the vertical filter was 6.99, 9.25 and 7.72, 7.13% and in the horizontal filter was 3.18, 8.21 and 8.36, 5.70%. For EC, the filtration rate in two electrical conductivities is 31.6 and 11.02 dS/m and in two times for vertical filter 5.39, 2.54 and 5.26, 2.18% and horizontal filter 12. 4, 1.90 and 2.99, 1.54% were measured. The filtration rate of TSS for two solutions containing TSS with concentrations of 0.75 and 1.5 g/l and at two times were checked and the filtration rate of the vertical filter was 48.93, 43.87 and 73.20, 80.25% and the horizontal filter purification rate was 29.66, 38.40 and 61.31, 67.05%. Finally, the obtained results showed; There is no significant difference in nitrate, EC and TSS purification between vertical and horizontal filters.

The objective of this research was to investigate the effects of surface, bubbler and drip irrigation methods on salinity distribution around pistachio trees under gardener management in a soil with sandy clay loam texture. For this purpose, an experiment in the form of split split plots with three treatments of irrigation methods in the main plot, the distance from the row of trees at four levels (0.5, 1, 2 and 3.5 meters) in the sub-plot and the depth of soil at four levels (0 to 30, 30 to 60, 60 to 90 and 90 to 120 cm) in the sub-sub plot in three replications was done. Then applied water and soil salinity during two crop years were measured. According to the results, the amount of applied water in border, drip and bubbler irrigation was 8150, 5060 and 6390 m3c/ha, respectively. The effect of irrigation methods and distances from trees on soil salinity was significant at 1% level and showed that drip irrigation is superior to other methods. Salt distribution at different distances from the trees row also showed a significant difference. Solutes accumulation under drip irrigation has started in surface layer at the edge of the wet environment and at a distance of 70 to 80 cm from the row of trees. Accordingly, the drip irrigation is one of the suitable irrigation methods for pistachio gardens, under properly designed, implemented and operated and soil sustainability consideration, and it is a suitable alternative to the conventional surface irrigation. In drip irrigation, the amount of irrigation water was 38% less than the surface irrigation. It is obvious that in the areas where the irrigation water is not a good quality and the effective annual rainfall unable to leaching the soil, the soil should be leaching annually using the surface irrigation method.

Considering the importance of designing the dam spillways in order to provide optimal dimensions while maintaining their optimal performance, an approach using weed algorithms (IWO) and water cycle (WCA) suggested to multi objective optimization of the trapezoidal labyrinth spillways. In designing the labyrinth spillways, the optimal model is to achieve a model with the highest possible flow passing through the spillway (efficiency) during flood times and the smallest possible volume, which represents the least amount of concreting and construction costs. In this regard, the effectiveness of two algorithms on the labyrinth spillway of the UTE dam investigated, and three different scenarios considered to evaluate the effect of different parameters on the results of optimization. The GD’s value for the IWO algorithm is lower than the WCA ones; on the other hand, the WCA algorithm has the most value of standard deviation and average repetition based on the GD criteria. This shows that IWO algorithm has high accuracy. Based on the S criteria, the average value in IWO equals 0.102 and in WCA is 0.367, so, regarding to the criteria’s values, IWA algorithm has more accuracy and convergence ratio comparing to the WCA algorithm in multi objective optimization of the labyrinth spillways. Applying the multi objective optimization method can provide a set of optimized answers for designers So that they would be able to select a suitable design in every condition and based on the defined values of costs and efficiency. In evaluating the proposed scenarios, the third one provides better optimal solutions than the second scenario by examining the optimal value for more variables. As a result, the variables of the discharge coefficient and the wall thickness have a significant effect on the optimization of the labyrinth spillways.

Ponds or traditional pools prevent water wastage by storing rainfall in to provide water for Guilan,s villagers. The purpose of this research is to investigate the role of ponds in the economic and social development of the village. This research is of applied type and its method is descriptive-survey. The validity questionnaire was determined by ten professors and the reliability of the questionnaire was 0.834 by performing the Cronbach's test. The statistical population investigated in this research were three cities of Guilan province. The results showed that the ponds provide 50% of the water needed by the paddy fields. 96% of the beneficiary farmers said that the ponds is essential for rice cultivation, 88% of them have a role in the continuation of agricultural activities, 74% of them have an increase in income from rice farming, and 48% of them have expressed the possibility of developing rice cultivation and reducing water stress effectively. Also, the analysis of the inferential statistics of the present study shows the positive economic and social impact of ponds from the perspective of beneficiary farmers, and it has been determined that there is a significant relationship between the role of ponds in increasing the area under rice cultivation by providing water, improving production efficiency, and increasing annual income and there is rice production as well as the continuation of agricultural activities, satisfaction with the main and secondary jobs affected by the dams, and finally the improvement of the economic and social status of the beneficiary farmers.

In-Site water harvesting is just one of the rainwater harvesting techniques with a wide range of traditional and innovative methods. Its efficiency can be improved by applying proper management and mechanization. By following the traditional architecture of Iran and modifying the existing rainwater harvesting methods, designed an In-Site water harvesting system for planting or groundwater feeding, called the Kajaveh, as a matrix of inverted cones. In order to study the influential factors on the Kajaveh system, 13 different treatments were examined. The results indicate that there is a specific base diameter and cone height which were determined according to the climatic and geographical conditions of the region and lead to the optimal operation of the Kajaveh system in water harvesting. Considering the different initial conditions for these treatments, results indicated that the case with a wall slope of 0.3 m/m, cone base diameter of 50 cm, loam soil, rainfall intensity of 12 cm/h, and rainfall length of 10 min, to yield the best rainwater harvesting results and on the average provided 14.9% more water than the unstructured state in the target area.

In this study, the effect of shallow and saline groundwater on the yield andparameters of quinoa in the greenhouse environment in two crop years 2018 and 2019 was investigated. The experiment was conducted in the form of factorial design of randomized complete blocks with 3 replications. The applied treatments included shallow (with depths of 0.6, 0.8 and 1.1 m) and saline (with salinity levels of 1,2, 6 and 10 decisiemens/meter of NaCl salt). The results showed that with the increase of water salinity from 1 to 10 decisiemens/meter and with the increase of the depth of the groundwater level, the percentage of groundwater contribution and the contribution of groundwater decreased significantly. The percentage of underground water participation for different salinity levels of 1, 2, 6 and 10 decisiemens/m in the depths of the water table 0.6, 0.8 and 1.1 meters respectively (37.43, 55.51, 71.12), (35/84, 51.21, 66.68,), (32.57, 46.92, 60.1397) and (30.15, 43/03, 56.93) were obtained. the increase in salinity caused a decrease in biological yield and an increase in the depth of the ponding surface caused an increase in biological yield and grain yield.The general results of the research showed that in none of the treatments, the water requirement of the plant was never provided by underground water in a hundred percent way, and a part of the water requirement of the plant was always supplied through irrigation during the growth period. It can also be said that the use of shallow and salty underground water resources (salinity less than 2 decisiemens/meter) in order to meet the water needs of the quinoa plant can reduce the amount of irrigation and contribute to the evaporation and transpiration of the plant

Leaf area index (LAI) is one of the most important parameters in plant growth studies, which has a direct relationship with the amount of light absorption, photosynthesis, plant physiological indicators, yield, etc. to be In this study, different growth functions such as Gompertz, Gaussian, polynomial and logistic were used to model silage maize leaf area index (as a dependent variable) based on growth degree days (as an independent variable). The studied treatments included pulse irrigation and continuous irrigation, each at three levels of MAD equal to 100, 80 and 60%, which were applied as a completely randomized block design. The results showed that based on R2, NRMSE and EF parameters, all four used models were highly accurate and precise in estimating the leaf area index during the growth period. Among the four investigated models, the logistic model showed the best result among different irrigation managements and levels. Also, this model had the highest efficiency among both continuous and pulse irrigation treatments, in MAD equal to 100%. The results of this study can be a basis for monitoring crop growth and evaluating different managements in the water, soil and plant chain, and finally a useful tool for management and planning to achieve food security.

this research investigated the effect of applying a magnetic field on the dimensions of soil moisture distribution pattern using saline water in the drip irrigation system. For this purpose, a physical model was built and experiments were performed as a time-based split-plot design at five levels of magnetic field (MF= 1500, 3600, 5600, 7600 and 9400 Gauss compared to the control sample) and five levels of salinity (S= 1.5, 3, 6, 9 and 12 ds.m-1) at three iterations on three soil textures of sandy clay, sandy clay loam and loamy sand. In the moisture distribution pattern, the maximum wetted width on the soil, maximum depth of wetted zone, maximum wetted width in the soil and maximum depth of wetted width were recorded at ten 30-minute intervals. Analyzing the recorded values indicated the significant effect of magnetic field × salinity × time on the depth of wetted zone, wetted width on the soil and wetted width in the soil at 30-minute intervals in all the three textures.The obtained results showed that salinity reduced the traits and application of magnetic field modified the effect of salinity (at low levels) and improved the traits in comparison with the control treatment. So, in the first 30 minute, the maximum depth of wetted zone was observed in loamy sand texture (25.5 cm) under MF9400S9 treatment, which is increased by 39.72 and 20% compared to the maximum value recorded in sandy clay and sandy clay loam textures respectively. Also, in the first 30 minutes, the maximum wetted width on the soil and maximum depth of wetted zone were observed in the sandy clay texture under the MF9400S3 treatment (46.75 and 55.5 cm respectively) which was increased compare to maximum value recorded in loamy sand and sandy clay loam

This study was accomplished to investigate water management indicators of irrigation systems in forage corn production in Tehran and Alborz Provinces. Forage corn farms were monitored during the growing season in the cities of Eslamshahr, Pakdasht, Shahr-rey and Savojbolagh. Corn applied irrigation water was determined by recording the irrigation schedule and measuring the flow rates. The water requirement of forage corn was estimated by Penman-Monteith method and by applying plant coefficients. The yield and water productivity for forage corn farms were obtained at the maturity stage. Irrigation applied water was statistically different during the growth season for the farms. Irrigation water averaged 3799, 6659 and 7240 m3 ha-1 for drip, sprinkler and surface irrigation systems, respectively. Results indicated that the farms with surface, sprinkler and drip irrigation consumed 18%, 13% and 32% less water than the gross irrigation requirement, respectively. The average volume of corn irrigation water in the four regions Islamshahr, Pakdasht, Shahrari and Savojbolagh was 6826, 5923, 6134 and 8126 m3/ha, respectively. Corn yield for sprinkler and surface irrigation systems averaged 51.3 and 52.8 t ha-1 for Eslamshahr and 49 and 55.5 t ha-1 for Pakdasht, respectively. The highest water productivity (20.83 kg m-3) in Pakdasht obtained from drip irrigation.