مجله آبیاری و زهکشی ایران
سال شانزدهم شماره 3 (امرداد و شهریور 1401)

Estimating water requirement and determining the actual amount of water is one of the most important factors in the management of agricultural water resources and one of the requirements of any irrigation project. The present study was conducted to investigate the water requirement system in determining the actual amount of peanut irrigation water based on the inverse solution of yield function under water stress in two crop years 2017 and 2018 in Guilan province. The experimental design was performed in the form of split plots in a randomized complete block design with three replications. The main factor of irrigation management included rainfed and 40, 60, 80, 100% Water requirement supply and sub treatment included two cultivars of peanut Guil and Jonobi. The results showed that the highest evapotranspiration in supplying 100% of water requirement in 2017 and 2018 was 446.7 and 524.1 mm in the Jonobi cultivar and 438.5 and 521.9 mm in the Guil cultivar, respectively. in the measured and estimated values of irrigation need by the water requirement system, the values of the coefficient of determination in the Jonobi and Guil cultivars are 0.65 and 0.64 respectively, and the root mean square error for Jonobi and Guil cultivars were 52.60 and 52.24, respectively, and the mean error deviation was 15.53 and 15.03, respectively. The agreement Wilmot index and efficiency coefficient of the model in 2017 and 2018 were 0.95 and 0.75 for the Jonobi cultivar and 0.95 and 0.76 for the Guil cultivar, respectively. According to the available results and statistical indicators, the water demand system provided a reasonable estimate of the actual amount of irrigation water in two peanut cultivars.

In this study, six extracting method of infiltration equation in furrow in Lavark field of Isfahan University of technology was performed and the rate of surface storage change has been calculated. . Information were collected, among three replications and five furrow irrigation event, double ring test, include cross-section, advance, recession, inflow and outflow rates, in addition to infiltration changes in submerged static condition and hydraulic conductivity of soil. The results were analyzed using a randomized complete block design. the study of infiltration process related to the various equations showed that there is high statistically significant difference at level of one percent in estimation of average infiltration in different time intervals of five using these equations. The most infilteration rate is related to volume balance equation and the least value was observed in input-output method results.On the other hand,According to result,the errors least(nearly zero) related to modified double ring equation.In fact, this equations,according to modified with the measured amount of water infiltration and the average infiltration time taken them, For the duration of the tests (average time of about one hour influence) is very near the measured values have been obtained on the farm. Generally, the equations with polynomial-power function estimated greater infiltration rate than simple power equations. This study showed that it is necessary to operate the farm experimentals corresponding with the applicational conditions of farm.

Due to the increasing population growthand limited resources available, achieving a suitable cropping pattern from which maximum utilization of production factors and inputs, especially water as a limiting factor, can be obtained, is an undeniable necessity. The aim of this study was to rank arable crops in the Farahan plain using multiple criteria and analytic hierarchy process. Forthis purpose using AHP method cultivable crops were ranked based on four indices of water, food, energy and economic profit and also the combination of these four indices. The results of AHP analysis showed that the economic profit criteria with a weight of 0.35 and then water consumption with a weight of 0.31 are the most important factors in prioritizing arable crops in the Farahan plain. The value of consistency ratio in all criteria and sub-criteria was less than 0.1, which indicates the acceptable level of agreement in the analysis. The results showed that the first priority of cultivation in the region based on water consumption criteria, were saffron, cumin and camelina, basedon calorie production, were forage sorghum, potato and corn, based on energy consumption were, forage sorghum, forage corn and grapes and based on the economic benefits were, lavender, thyme and borage, respectively. The results showed that the current cropping pattern in the study area is not an acceptable cropping pattern and optimizing the cropping pattern based on the multiple criteria and prioritizing crop cultivation based on these criteria should be on the agenda of managers and decision makers. Prioritization of crops cultivation based on the fourcriteria mentioned in this study provides the foundation for the gradual implementation of the optimal cropping pattern in the plains. Therefore, according to the results obtained in this study, it is suggested to use multi criteria decision-making methods to prioritize arable cropsand select the optimumcropping pattern.

One of the important factors for agricultural irrigation management and planning is accurate estimation of reference evapotranspiration (ETo). The application of the standard model (FAO-Penman-Monteith) to estimate ETo is restricted due to the availability of climatic variables including temperature, humidity, radiation, wind speed as well as the availability of the mentioned hypotheses in FAO 56. Accessibility to all climatic parameters or satisfaction of the FAO-Penman-Monteith assumptions are often not possible in some areas or in controlled environments (greenhouses). Therefore, it is preferable to use methods that can provide an accurate estimate of ETo with fewer input parameters. The aim of the present study was to evaluate the performance of two methods of artificial neural networks (ANNs) and adaptive neuro-fuzzy inference system (ANFIS) for estimating ETo in the research greenhouse of the College of Agriculture and Natural Resources of the University of Tehran, located in Karaj, Iran. Based on the measured climatic parameters inside the greenhouse, different combinations were created and evaluation indicators were calculated for each method and scenario. The best neural network structure was obtained for Scenario 4 (radiation, temperature, humidity) with 7 neurons in the hidden layer and Bayesian Regularization training algorithm. ANFIS model was designed with different membership functions. The results showed that there was no significant difference between the performance of the ANFIS method under different scenarios. In other words, even with temperature and humidity data, ETo can be simulated with high accuracy by ANFIS method. Comparison of evaluation indicators between ANFIS and ANNs models showed that ANFIS performed better than ANNs method. The calculated relative root mean square error (RRMSE) for scenarios 1 to 4 in ANNs model was equal to 12.70, 2.23, 2.12 and 2.10% however it was equal to 1.41, 0.80, 1.06 and 1.01% in ANFIS model.

Sustainable water resources management is the hardest challenge facing human communities, and improvement of understanding complex interactions in coupled human-water systems is very important in achieving it. In recent decade, socio-hydrological modelling is of the most widely used methods for description of interactions and co-evolution of human-hydrological systems. In this study which is the first attempt to develop a conceptual framework for socio-hydrological modelling in Iran with the aim of understanding coupled human-water systems, after development of the conceptual framework, its application in Mashhad basin based on the qualitative system dynamics approach has been shown. In the proposed framework, the impact of managerial decisions on the natural system has been defined as the behavioural response variable, influenced by community sensitivity. Results showed that, now, fixes that fail, limits to growth, and success to the successful are dominant archetypes in Mashhad basin. In fact, behavioural response influenced by water demand has resulted in managerial decisions aiming at profit-oriented economic growth with no consideration for the natural system limitation. Accordingly, overexploitation of water resources regardless of the renewal rate of water resources has occurred, and community sensitivity with the aim of maintaining the water system sustainability has played no role in managerial decision-making. As long as the role of other water-sensitive social levels in behavioural response is ignored, the community sensitivity loop as a balancer balancing the human-nature relationship remains missing and defective forever.

Wind drift and evaporation loss (WDEL) in sprinkler irrigation systems are a factor that affects the water delivery in a field and reduces the uniformity of spraying. So, predicting these losses can play an important role in improving the performance of them. In this study, artificial neural networks (ANNs) have been used to estimate the hourly sprinkler discharge efficiency (SDE), which, in turn, is dependent on WDEL. The effective parameters in estimating WDEL, which were considered as model inputs, were selected by calculating Spearman rank correlation coefficients. Accordingly, wind speed, temperature, relative humidity, and reference evapotranspiration were considered as model inputs, whereas SDE was considered as model output. The performance evaluation of the developed neural network model was done using 1024 real data obtained by the Strip structure for estimating WDEL. The proposed model, which was a 4-19-16-1 model with a Bayesian regularization training function, was selected upon testing 3780 different neural networks. The results of this study showed that the developed model can accurately estimate the hourly values of sprinkler discharge efficiency (R= 0.84, RMSE= 1.6%, MAPE= 1.19) and can be used as a reliable method in evaluating the performance of sprinkler irrigation systems.

In arid and semiarid regions with limited water resources, using any method that, it is increased crop yield by applying a certain amount of water, it will be an effective management strategy to increase water use efficiency. The aim of this research was, to study of magnetic water and transparent plastic mulch effect on yield and water use efficiency in green beans cv. Alamout. Research was performed as split plots experiment based on completely randomized blocks design with three replications from June to October 2018 at the Research Farm of Agricultural Faculty, University of Zanjan, Iran. The main factor of the experiment was crossing and not crossing irrigation water from the magnetic field and sub factor of the experiment was use and non-use transparent plastic mulch. Crop water requirement was calculated by using real time meteorological parameters data of Zanjan synoptic Station and FAO-Penman-Monteith approach. Results showed, the highest increase in mean leaf chlorophyll content, mean leaf area, mean pot length, mean number of pods per plant, mean crop yield and mean water use efficiency were obtained in the conditions of together use of magnetic water and transparent plastic mulch which compared to control treatment, they were 32.2%, 13.5%, 19.4%, 52%, 40.8% and 40.8% more (respectively). The average leaf relative water content in transplant plastic mulch treatment was 6.5% higher than non-mulch treatment and in magnetic water treatment was 6.8% higher than non-magnetic water treatment (significant increase). As the research results, it is recommended in Zanjan region, magnetic water and transparent plastic mulch are used together in plant cultivation.

The Water-Food-Energy NEXUS is a framework for building a governance system that aims to facilitate cross-sectoral partnerships and improve and strengthen coherent policies for planning and governance. Accordingly, the present study analyzes the water governance structure focused on the Water-Food-Energy NEXUS and evaluates the power distribution of responsible institutions and partners in the governance structure of water resources management in Iran. according to the Sixth Economic, Social and Cultural Development Plan. For this purpose, the cooperation network was reviewed based on the legal duties of the responsible institutions and organizations in the axes of water resources development program, agriculture, environment and natural resources and energy. Examining the rules of the development plan shows that attention to the Water-Food-Energy NEXUS in the water governance structure has been neglected, and a realistic understanding of cross-sectoral conflicts and the anticipation of conflict resolution mechanisms require serious attention in the plan. Considering the number of collaborations of network actors, the formation network matrix was analyzed using Ucinet and NetDraw software based on the indicators of degree centrality, intermediate centrality, density, geodetic distance and cut points. Findings Analysis of social networks, considering the concentration of power in the Ministry of Energy in the current governance structure, emphasizes on strengthening the position of power of the Ministry of Jihad Agriculture in line with water demand management policies and strengthening the relationship between financing institutions and water resources development laws. Also, strengthening the role of monitoring and inspection institutions in order to increase transparency and accountability, strengthening the legal relationship between universities and the national technology and innovation system to support the knowledge-based economy, and developing the participation of local communities and non-governmental organizations in decision-making. Taking from other expandable points is the structure of the country's water governance.

The present study focuses on the effect of viscoelastic properties on the optimal design of pressurized irrigation system taking into account the impact of water hammer. For this purpose, the three models, the optimizer, the hydraulic steady solver (HSS), and hydraulic transient solver (HTS) were coded together in the form of a computer model. In the optimizer model, the initial population is created from the available diameters. Then, for each member of this population, in the HSS, the values of pressure in the nodes and velocity in the pipes are calculated. These values are sent to HTS as an initial condition. In the HTS, by applying a water hammer condition on the system, the maximum overpressure in each node is calculated and the results are sent to the optimizer model. Here the value of the objective function is calculated by observing the constraints for each member of the initial population and relative compatibility is obtained for all members. By applying the operation of mutation, intersection, replacement with the elitist approach, the next generation is finally calculated and the mentioned steps are repeated until the condition of stopping the calculations and determining the optimal answer is reached. Validation of the HTS in viscoelastic pipes using data measured at the Imperial College (London, UK) and considering three Kelvin–Voigt elements and retardation times of 0.05, 1.5 and 5 seconds for these three elements are done. The results showed that for wave speed of 390 m / s, the measured pressure fluctuations are in good agreement with the calculations. After confirming the model results, water hammer simulation of Ismailabad network in the current situation, which is composed of GRP and HDPE pipes, was performed with and without considering the viscoelastic properties for polyethylene pipes.

Long-term recognition of river water quality and quantity is important for examining changes in the past and predicting the future. Therefore, in this study, qualitative and quantitative changes in the water of the Polroud River in Guilan province have been investigated using graphical methods and statistical analysis. In this study, the recorded data of water quality variables in from 1999 to 2018 were used. Schuler diagrams were used to evaluate drinking quality, Wilcox for agricultural quality, Piper to use water type, and Mann-Kendal method to examine time series and Pearson correlation test to examine the relationships between parameters. According to the results obtained from the Schuler diagram, the water quality of the River is in a good condition in terms of drinking and for the seasons of Spring, Summer, Autumn and Winter. The results of the Wilcox diagram show that the river water quality is agriculturally in a good and suitable condition and the results of the piper diagram show the water type is calcium bicarbonate. Also, according to the Mann-Kendal test, there is an increasing linear trend in the annual flow of the river. The results of qualitative statistical analysis of the parameters studied in this study in the period from 1999 to 2018 showed that in the summer the measured parameters have high values compared to other seasons so that the highest mean for the EC index in this season is equal to 290.85, TDS was equal to 246.3, PH index was equal to 7.65. Also, in the flow study, it was found that the highest flow rate is related to spring with a rate of 30.82 m3/s and the lowest in summer with a rate of 10.73 m3/s. The results of Pearson showed that there is a direct and significant relationship between EC and TDS.

The correct estimation of crop evapotranspiration stress coefficient (Ks), causes the accurate estimation of evapotranspiration under water stress conditions. In this research, maize was planted in mini-lysimeter and its daily evapotranspiration amount was measured. The experiment was performed in a completely randomized design. Water stress was applied by soil water depletion at levels of 55%(I1), 65%(I2), 75%(I3) and 85%(I4) of total available water (TAW). In control treatment (I0), the soil water amount was kept in readily available limit. The readily available water limit (RAW) was considered as constant in the growing season and its rate was defined as the depletion of 40% of TAW. In another method, the RAW limit was estimated separately at the maize growth stages of initial, development, mid and late. At the time of increasing the stomatal resistance of leaves (due to water stress), soil moisture was measured. The RAW limit in the mentioned growth stages, was estimated to be 45%, 65%, 60% and 70%, respectively. Therefore, the Ks coefficient was estimated in two methods of variable (in four growth stages) and the constant (in the growth period). Maize evapotranspiration amounts under water stress were estimated by multiplying the control evapotranspiration amount on the Ks coefficients. Then, the actual and estimated amounts of maize evapotranspiration (under water stress conditions) were compared. The results showed that using the constant Ks coefficient for estimating the maize evapotranspiration amount in the growth stages, was not successful. By using the variable Ks coefficient, was considered the maize sensitivity to water stress in the growth stages. Therefore, a suitable estimation of maize evapotranspiration amount was performed under water stress conditions. As a result, for determination the maize evapotranspiration amount under low irrigation management conditions, must be considered the separate Ks coefficients in the growth stages.

In recent years, increasing population and food demand has led to greater use of water resources, fossil fuels (mechanization development) and chemical inputs in agriculture, and consequently has many environmental problems. In this study, the amount of environmental loads and environmental impacts of agriculture in the Urmia Lake basin was determined by assessing the life cycle of different major crops (wheat, sugar beet, tomato and corn). This research was conducted on 17 farms in different parts around Lake Urmia. The fields were selected in such a way that they represent the dominant crops of the region as well as the irrigation systems used in the region. Data used in this study were collected through field measurement methods, questionnaires, interviews with farmers and experts and using the Ecoinvent database. Data evaluation was based on life cycle assessment analysis and was done by SimaPro software. The results showed that in general, the largest share in energy consumption was for diesel and nitrogen fuel consumption, and farms with surface irrigation system had higher energy consumption than pressurized irrigation farms. Among the studied farms, both of basin and furrow irrigation methods achieved the lowest energy productivity (0.53 kg/MJ) while drip irrigation resulted in the highest (1.2 kg/MJ). The results also showed that in all farms the share of non-renewable energy (76%) was higher than of renewable energy (24%). Direct release from farms had the greatest impact on environmental degradation.

The aim of the present study was to analyze the correlation and simulation of the values of reference evapotranspiration of meteorological stations in the Lut Desert (Bam, Birjand, and Tabas) in the period 1984-2019 using common copulas and corresponding wind speed on a monthly scale. By examining the correlation between the pair-variables of wind speed and reference evapotranspiration in Bam, Birjand, and Tabas stations, the correlation was evaluated about 0.7, 0.76, and 0.80, respectively. By examining the structure of two-dimensional copulas and their conditional density based on different criteria, the Galambos copula was selected as the best copula for all stations. By selecting the best marginal distribution and the best copula, the frequency analysis, joint return period and copula-based simulation were presented. By presenting the joint probability curves, the probabilities of both wind speed and reference evapotranspiration at each station were presented simultaneously in the form of typical curves, which can provide very useful information about the probabilistic behavior of the studied data. Finally, the reference evapotranspiration values were simulated using a copula-based model and wind speed values. The simulation results of the mentioned values showed that the correlation of the pair-variables was appropriate. The accuracy, efficiency and error rate of simulating the values of reference evapotranspiration values were evaluated using various statistical tests. Successful simulation of this parameter is in fact a reason for accurate selection of the copula structure, which indicated a maximum error rate (RMSE) of 0.1 mm per day and 98% efficiency for all stations. By application of this algorithm in simulating the values of reference evapotranspiration and presenting its estimated relationship in the region, the amount of reference evapotranspiration can be easily simulated with available meteorological data and without much computational complexity.

Limited water resources and increasing the need for it in the agricultural sector have made the use of strategies to increase physical productivity and improve economic water efficiency in the agricultural sector inevitable. In this regard, water productivity indicators can be considered as one of the main components in the field of national planning. In this research, economic and physical productivity was calculated using Indicators Crop Per Drop (CPD), Benefit Per Drop (BPD) and Net Benefit Per Drop (NBPD) indicators for lands under citrus and paddy in the west and center of Mazandaran province, which were irrigated as a Modern (irrigation and underwater irrigation). the method used in this study is based on field visits and perceptions and including performance estimation, water consumption, net and gross costs. The study area in Mazandaran province was divided into four plains including Ramsar - Chalus, Nor - Noshahr, Amol - Babol and GhaemShahr - Joybar. The results of this study showed that the average economic and physical productivity in lands under citrus culture and paddy for CPD index, 5.8 and 0.76 kg/ m3 per hectare, for BPD index, 261 and 175, 1000 Rials/m3 per hectare for the NBPD index, 209 and 127, 1000 Rials/m3 per hectare. Therefore, citrus and paddy fields in Nor - Noshahr and Ramsar - Chalous areas have the best performance in terms of economic productivity of NBPD index and Nor - Nowshahr and Amol - Babol areas have the best performance in terms of CPD index. According to the results of the present study, water management in the field, the use of modern irrigation methods and changing the pattern of culture due to the climatic. Also, creating the necessary infrastructure to replace malfunctioning machines and incentive and punitive policies can be an effective way to increase water productivity.

The significant reduction in water volume of the two important wetlands of Hamoun and Jazmourian in the arid region of the southeast of the country has had several economic, social, and environmental consequences. Although the reduction of water in these two wetlands is influenced by climatic and human factors, often climate change, especially the decrease in rainfall is considered as the main factor. Therefore, in this study, the trend of precipitation changes in the southeastern region of the country is investigated using the CHIRPS satellite product. To evaluate the accuracy of CHIRPS compared to station precipitation data, the Categorical Statistical Indices including Probability of Detection (POD), False Alarm ratio (FAR) and Critical Success Index (CSI) and statistical criteria including coefficient of determination (R2), Pearson correlation coefficient (PCC), root mean square error (RMSE) and mean error (ME) were used in three time scales: daily, monthly and annual. The results showed that this product does not have good accuracy in detecting the number of rainy and non-rainy days (POD<0.2, CSI<0.2, FAR>0.6). This product does not provide an accurate estimate of daily precipitation (R2<0.2 and PCC<0.4), but has relatively good accuracy on a monthly and annual scale (R2>0.6 and PCC>0.8). The trend analysis of precipitation in the southeastern region of the country showed that in general, the amount of precipitation on a monthly, seasonal and annual scale has been increasing, or in some cases insignificant decreasing, during the last 40 years. Accordingly, the decrease in the water level of wetlands cannot be due only to changes in rainfall, and the role of other factors, especially human activities should be considered.