مجله آبیاری و زهکشی ایران
سال چهاردهم شماره 6 (بهمن و اسفند 1399)

Downscaling methods seem to be a reasonable solution to solve the problem of having no simultaneous high spatial and temporal satellite data, and it is possible somehow to meet the requirement of having high spatial-temporal resolution satellite data for monitoring the natural phenomena such as evapotranspiration, through these methods. Sentinel-2 satellite launched in 2015 enables to provide 10-m spatial resolution data with a 5-day revisit time; however, its sensor does not acquire data in thermal infrared wavelength. This study aims to generate 10-m daily evapotranspiration maps based on Sentinel-2 and MODIS data fusion for Amir-Kabir Agroindustry farms. For this purpose, STARFM and improved TSHARP methods were applied for downscaling MODIS data to Sentinel-2 data. To achieve this goal, First, MODIS visible and near and middle infrared bands were downscaled by STARFM to 10-m spatial resolution. Then, improved TSHARP was applied for downscaling MODIS thermal band to 10-m spatial resolution and SEBAL algorithm fed by the downscaled bands, was used to produce daily evapotranspiration map with 10-m spatial resolution. Assessing downscaled evapotranspiration maps with those derived from FAO Penman-Monteith equation indicated a RMSE of 0.64 mm/day showing efficient performance of the downscaling framework proposed for 10-m daily evapotranspiration mapping in this study.

Corn is one of the most important agricultural crops in Iran. In order to achieve appropriate yield, biomass and water use efficiency, it is necessary to evaluate the effect of irrigation amounts, cultivar types and plant densities on corn yield. Because of time-consuming and high cost in field studies, crop models have been proposed to study mentioned scenarios. In order to evaluate SWAP, a field study was conducted on two maize cultivars (V1 and V2 representing median cultivar SC500 and early cultivar Sc302, respectively) under different plant densities (D1, D2 and D3 representing 75000, 85000 and 95000 plants.ha-1, respectively, for SC500 and 80000, 90000 and 100,000 plants.ha-1 for SC302 cultivar) with different irrigation volumes (I1, I2 and I3 indicate as 75, 100 and 125% irrigation demand, respectively) in Karaj during two years (2006-2007). Results showed that SWAP had the best accuracy to simulate corn yield in V1, I3 and D3 in comparison to other treatments. SWAP accuracy was better in V2, I3 and D2 treatments for simulation of corn biomass. The model precision for water productivity was better in both cultivars, I3 and D3. In general, based on normalized root mean square error, the model accuracy for simulation of corn yield, biomass and water productivity were 0.14, 0.13 and 0.16, respectivly. SWAP efficiencies for mentioned parameters, with values equal to 0.98, were acceptable. So, it is proposed to use SWAP for simulation of yield, biomass and water use efficiency under above mentioned treatments.

Optimal and efficient application of water resources due to the recent water crisis and droughts in the country is very necessary. In this regard, the use of modern irrigation methods is one of the solutions that has been developed to increase water productivity in the country. Therefore, this study was conducted to compare the physical and economical efficiency of water in drip and surface irrigation systems and net benefit per cost in vineyards and walnut orchards. In this study, the volume of applied water was calculated by measuring the flow rate of the water source, the number of irrigations and the hours of irrigation in each irrigation. The water requirement was calculated based on the last 10 years of meteorological data and compared with the estimated water requirement in the national water document. Water productivity was estimated based on yield per unit volume of water (CPD), income per unit volume of water (BPD), and net yield per unit volume of water (NBPD). The results showed that drip irrigation method compared to surface irrigation method reduced the applied water of grape and walnut crops by 40 and 54%, respectively. Water productivity in vineyards and walnut orchards in drip irrigation system was calculated as 25.1 and 1.81 and in surface irrigation as 7.8 and 0.88 kg / m3, respectively. Calculated water requirement based on the last ten years of meteorological data in these two products was greater than the value stated in the National Water Document. Comparison of the average amount of applied water with the calculated water requirement indicated a deficit irrigation in most of the studied gardens. Comparison of Economic productivity of water in the two crops showed that this index in drip irrigation method is much higher than surface irrigation method. Net yield index per unit of water used (NBPD) in drip irrigation method in grape and walnut crops are 231 and 117, respectively, and in surface irrigation method 110 and 115 thousand Rials per cubic meter.

The reference evapotranspiration (ETo) is one of the most important effective factors in hydrological cycle and has been used in the calculation of many drought and aridity indices and the studies related to the projection of climate change impacts. The investigation of climate change impact on ETo is necessary for longterm scheduling and management of water resources. In this study, the downscaled projections of two climatic models of EC-EARTH and GFDL-ESM2M (based on RCP8.5 scenario) under CORDEX project were used and using the modified method of FAO Penman-Monteith and by considering the effects of the atmospheric CO2 concentration on plants stomatal resistance, the ETo was estimated for the historical period (1976-2005) and future period (2006-2100) in lake Urmia basin. The results of investigation of ETo changes in three near-future (2011-2040), mid-future (2041-2070) and far-future (2071-2100) periods in comparison to the historical period revealed an increasing trend of ETo especially for far-future. The contribution analysis of the meteorological variables in ETo changes showed that the maximum temperature (with the average contribution of 91.54 %), the minimum temperature (with the average contribution of 37.68 %) and the atmospheric CO2 concentration (with the average contribution of 41.40 %) will have the most contribution in ETo changes. However, because of increasing trend of the agricultural development, the effects of irrigation on the climate and ignoring the irrigation effects in climatic models, projection of ETo changes based on climatic models may be along with some uncertainties.

In this study, the effects of the exploitation of the Sefidrood drainage irrigation network on Anzali International Wetland in the framework of IWRM are investigated. For this purpose, first, the values of hydrological indicators including water level, area, and volume of Anzali wetland were determined by considering economic, social and ecological conditions at the desired and minimum levels. After examining the current condition of the wetland, the relationship between the inflow to the wetland and the upstream exploitation system was simulated using the WEAP model and the model was calibrated for the baseline scenario with R2 and RMSE of 0.99 and 0.47, respectively. The results of scenario analysis in different conditions showed that currently the volume and level of the wetland are more dependent on the sea level and the inflow to the wetland only in flood conditions can show its effect on the volume and level of the wetland. Based on the results, it can be said that the ecological life of Anzali wetland is more affected by the discharge of the wetland to the Caspian Sea than by the quantitative management of water resources upstream of the wetland and water abstraction from Sefidrood irrigation and drainage network for agriculture, animal husbandry and aquaculture.

In order to investigate the effect of planting season and compare the performance of different cultivars of greenhouse cucumbers in water stress conditions, thise experiment was performed as a factorial in a completely randomized design with three replications in the Chahanimeh greenhouse complex located in Zahak city of Sistan and Baluchestan province. The treatments included three cultivars of greenhouse cucumbers in Sistan region (Sina, Baresh and Negin cultivars), three irrigation water levels (100%, 75% and 50% plant water requirements) and two planting seasons (first stage cultivation in the first week of October the second stage in the third week of February). Harvesting was done every four days. The weight and number of fruits, the diameter and length of the cucumber in each plot were carefully measured. For better comparison and analysis, mean time data of 1.5 months after the first harvest were used in both planting seasons. Also, performance and water productivity at the end of both seasons were calculated. The results showed that the effects of planting season, cultivar and irrigation water at the probability level of five and one percent had a significant effect on the measured parameters. The highest value of the measured parameters was obtained in the treatment of 100% of the plant's water requirement, which was not significantly different from the 75% treatment of the plant's water requirement. Yield and productivity of irrigation water in the first season of cultivation were 144.6 ton/ha and 20.4 kg/m3, respectively, which is higher than the second season of cultivation (128.7 ton/ha and 17.3 kg/m3). Different cultivars had different results in the first and second seasons of cultivation. In the first season of cultivation, Sina yield (158.2 ton/ha) was better than other cultivars. In the second season, Baresh cultivar yield (156.4 ton/ha) was better than Sina and Negin. Therefore, according to the obtained results, the amount of water consumption can be reduced by 75% and the saved water can be used in the second season of cultivation. Also, considering that Sina cultivar had better results in the first planting season and Baresh cultivar in the second season, these two cultivars should be used in each season.

Irrigation management is one of the most important factors affecting the development and expansion of the plant root. The aim of this study was to investigate the effect of different deficit irrigation treatments on the root characteristics of fodder maize (KSC 704) in surface drip irrigation system. This research was conducted in agricultural research center of Khorasan Razavi during the 2014 growing season. A factorial experiment based on randomized complete blocks design with nine treatments and four replications was carried out. Treatments included full irrigation (FI), deficit irrigation (DI) and replacements of 80 and 60% of total water requirement, partial root zone drying (PRD) at 100, 80 and 60% of water requirement and fixed partial root zone drying (FPRD) at 100, 80 and 60% of water requirement. Water requirement was determined based on compensation of soil moisture deficit using an electromagnetic moisture meter. Water was measured by volume meters and distributed in the field. The first stress was applied at the 6-leaf stage of maize. Two weeks after applying the first deficit irrigation treatment in the 10-leaf stage of the plants, the first root sampling performed. Dry weight and volume, lateral and deep penetration of roots were measured at each sampling. The results showed that in all treatments the average amount of all measured traits decreased with decreasing water consumption. There was no significant difference among root dry weight of FI, PRD100 and PRD80 treatments. Root volume was affected by water stress but application of PRD80 method prevented the negative effects of water stress on root volume. Therefore, PRD method is more efficient compared to DI and FPRD methods when applied water stress, and water and nutrients will be absorbed at a higher level by root.

Soil moisture is of particular importance in the study of water resources and agriculture. The microwave electromagnetic spectrum does not have the physical limitations of other radiometric spectral in measuring soil moisture, but they often have very large pixel dimensions (more than 10 km). In this study, in order to apply soil moisture remote sensing data at the farm scale, using field soil moisture measurement data in the Nishabour plain during 2017-2019, calibration of AMSR2 retrieval data was performed. It turned out that altitude and vegetation changes are among the key factors affecting calibration accuracy. Based on the theory of thermal inertia and with the help of MODIS sensor images, the interactions of the average daily soil moisture and the daily surface temperature difference between the two MODIS and AMSR2 sensors were investigated. Using it, downscaling linear relationships of soil moisture images were obtained to convert the image dimensions from 25 km to 1000 m. Validation of R2 statistical indices with a minimum of 0.73 and a maximum of 0.84, MAE and RMSE with a range of 1.6 to 4, showed that the algorithm used in the downscaling is well able to reflect the interactions between rainfall, soil moisture, vegetation and changes in canopy temperature profile and this feature reinforces its application in agrometeorological studies.

Determination of wells' capture zones are one of the important issues which must be considered in every aquifers. Methods used for depicting this area divides into two simple and complex methods. Through the simple one several mathematical equations utilized and in the complex method, numerical models are applied. In this study, for the first time, the capture zone of the extraction wells in a standard confined aquifer and Birjand unconfined aquifer was determined using Feflow simulation model. After the simulation procedure in the period of 1390-1391 with monthly time step, the groundwater head is obtained, then the capture zone for each well was depicted. In confined aquifer this area individually determined for 3 extraction wells in two periods of 50 and 180 days. The results showed that the extension of the capture zone for all three wells is toward the part of the aquifer with higher groundwater level. Also, the results revealed that, in areas of the aquifer with higher transmissivity coefficient, the zone is more extended and for the areas with lower transmissivity coefficient, its width decreases and becomes narrower. For instance in second well the width of capture zone in the third zone is 302.86 m, however, it is 267.46 m in the second zone. In Birjand aquifer which consists of 190 extraction wells, 5 wells were chosen randomly to depict capture zone for them in five years and thirty years period. The results revealed that the extension of the capture zones were corresponded to the flow direction. Also, extraction rate of wells and hydraulic conductivity coefficient were two effective parameters in the shape of these zones. As the fifth well in Birjand aquifer with the least value of discharge rate had the smallest length of capture zones among all the wells.

The volume of applied water in the agriculture as an indicator to evaluate the optimal use of water resources, plays an important role in macro management and planning in the field of water management and engineering. Experimental grape orchards were selected across the Markazi province to cover various factors including irrigation methods, soil texture, type of water source (surface or groundwater) and irrigation water quality. Selected orchards were monitored during the growing season 2018-2019, and different parameters such as irrigation dates, amount of irrigation, irrigation duration, and so on were recorded. The results showed that the irrigation interval in the grape orchards varied from 6 to 20 days and the average irrigation water depth was between 30 and 185 mm. The results showed that the amount of irrigation water consumption of grape orchards in the Markazi province was different depending on the type of irrigation systems, the number of irrigation and management of the orchard, and its amount varied from 5973 to 18168 m3/ ha. Also, the application efficiency of irrigation in the studied orchards varied from 35 to 100 percent, average being 63%. The water productivity for this crop varied from 1.1 to 3.7 kg/m3 and it’s average was 2.62 kg/m3 in the Markazi province. Overall, the results of the measurements carried out at the Markazi province showed that regardless of the type of irrigation system used, the irrigation management by the farmer plays an important role in total water use in the orchards.

Unsteady flow analysis is performed using the equations of St. Venant. Calculating the slope of the energy line (Sf) is of great importance in the analysis of unsteady flow. Since Sf is equal to the hydraulic gradient (i) in a coarse porous media, the calculation of i is of great importance. In the present study, using experimental data recorded in a steel cylinder with a diameter of 16 cm and a length of 70 cm, 40 cm of which is filled with rockfill with three small, medium, and large grains, investigated the unsteady flow in a confined porous media. The particle swarm optimization (PSO) algorithm is used to optimize the Forchheimer binomial relation coefficients used in steady flow (a, b) and the triplet relation used in unsteady flow (a, b, c). The results of the present study indicate that the values related to the mean relative error (MRE) in the case of using a triple relation to the binomial relation to calculate the hydraulic gradient of unsteady flow, in small materials 14.5, in medium materials 14.7 and in large material, it has improved by 12.2%. The value of the third sentence is a triple relation to the hydraulic gradient ((cdv/dt)/i) in 7.23% in small materials, 14.79% in medium materials, and 17.01% in large materials. In other words, since with increasing the diameter of the material, the efficiency of the nonlinear (non-Darcy) relation increases compared to the linear (Darcy) relation, the third sentence of the triple relation also has a greater effect on the hydraulic gradient calculations.

One of the ways to increase the quality of irrigation water is to magnetize it. Research in the research greenhouse of Ferdowsi University of Mashhad in 2018.The experiment was completely random in the form of a factorial design and three treatments included irrigation method (usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying and three levels of magnetic water). This included: ordinary water, one-time magnetic water with a Tesla intensity of 0.367 and Tesla 0.633). Examination of the experimental results showed that in the usual irrigation method and magnetic water with a Tesla intensity of 0.367, the highest plant height (110 cm) , Dry weight of aerial limbs (41.9 g.plant-1, dry weight of roots (17/1 (g.plant-1 and root volume (137 cm3.plant-1) and in the usual irrigation method and water Tesla's magnitude of 0.633 was the highest leaf area (25.24 cm2), total fruit weight (508.18 g), lycopene (48.6 (mg.gfw-1). fixed partial root-zone drying magnetic water with .0.367 intensity Tesla The highest amount of chlorophyll b (0.489 mg.gfw-1) and single fruit weight (48.03 g) and in the intensity of Tesla 0.633, the highest percentage of dried fruit (%11.1) was observed. The highest water use efficiency Total biomass (36.6 g / liter) was observed in fixed partial root-zone drying and control water. alternative partial root-zone drying and magnetic water with Tesla 0.367 intensity, maximum leaf-stem ratio (1.37 g.plant-1), air-to-underground ratio (3.14 g.plant-1) and root length (53.2 cm) was observed, but the highest content of relative moisture content of leaf water in alternative partial root-zone drying and magnetic water showed Tesla with a intensity of 0.633. Among the irrigation methods, the highest total fruit weight in each pot was observed in usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying was observed as variable and both Tesla 0.367 and 0.633 intensity of magnetic water were able to improve traits. It is recommended to reduce the effects of drought stress, it is recommended to use this method that is safe, easy and safe for the environment.

To evaluate the salinity tolerance of Milk thistle, an investigation was conducted in a completely randomized design with 3 replications in a pot in the greenhouse of the National Salinity Research Center. Experimental treatment includes 5 levels 0.44 (control), 3, 6, 9 and 12 dS/m. The results showed that the application of salinity levels significantly reduced all the studied traits. Regarding some growth and yield-related traits, increasing salinity from control to salinity of 12 dS/m reduced plant height by 89%, grain yield by 79%, biological yield by 46%, and harvest index by 59%. Also, with increasing salinity level, relative water content decreased by 9.86% and ion leakage increased by 38.53%. Potassium and sodium elements of plant shoots were also significantly affected by salinity so that increasing salinity from control to 12 dS/m had a significant effect on reducing the ratio of potassium to sodium and caused a 69% decrease in this ratio. The results showed that the salinity tolerance threshold (seed yield) was 0.19 dS/m and a 50% reduction in yield was obtained at a salinity of 7.21 dS/m. In general, according to the results, it seems that Milk thistle does not have a high tolerance to salinity.

In this study, spatial and temporal changes of ecological footprint components and the economic value of virtual water of tomato crop have been estimated during the 2005 - 2017 in the producing provinces. The results showed that the average ecological footprint of water in the mentioned product is 327.2 m3/ton, which is the share of green, blue and gray water footprint is 4.6%, 83.5% and 11.95, respectively. Bushehr province (86.8 m3/ton) and Qom province (771.6 m3/ton) have the lowest and highest water footprints in Iran, respectively. The highest share of green water footprint is related to Bushehr, Southern Kerman, Mazandaran and Hormozgan provinces while the highest share of blue water footprint is related to Lorestan, Kohgiluyeh, Boyer-Ahmad and Khorasan Razavi provinces. The average economic value of virtual water in Iran is 0.78 USD/m3, which is the highest (1.68 USD/m3) and the lowest (0.29 USD/m3) in Bushehr, Kohkiluyeh and Boyer-Ahmad, respectively. The average volume of virtual water for tomato production is 3925.99 MCM per annual, of which 99% is exported annually from the Iran. The share of Qom, Guilan and South Khorasan provinces in the export of virtual water is the highest. Finally, the results of this study showed that due to water and soil limitations in Iran, ecological footprint index, virtual water volume and awareness of virtual water trade provide useful information for prioritizing tomato cultivation in susceptible areas. Therefore, it is suggested that this concept be used for the allocation of agricultural water resources and policy to stop or develop cultivation at the provincial and national scale.

In recent years, increasing population and limited water and arable land in Iran have led to significant investment in greenhouse production. Due to the effect of greenhouse microclimate conditions on the quantitative and qualitative yield of the product, the use of mathematical models to study and microclimate simulation of the greenhouse is necessary. The objective of this research is to apply and analyze an energy balance model using meteorological data outside the greenhouse to simulate microclimate conditions and the transpiration in a greenhouse. The study was conducted in a commercial greenhouse with plastic cover and an area of 4333 square meters. Temperature and relative humidity data were collected inside the greenhouse with 21 data loggers. For collected meteorological data outside the greenhouse, the meteorological station installed on the roof of the greenhouse and the data of the Tuyserkan synoptic meteorological station were used. A combination of energy balance and transpiration equation was used to estimate temperature, relative humidity and crop transpiration inside the greenhouse. Estimated transpiration was modified by combining the energy balance model and the Stanghellini transpiration equation. The pattern of temporal variation of the simulated and measured values of temperature and relative humidity inside the greenhouse was similar. The root mean square error of the simulated temperature for mechanical ventilation and natural ventilation was 0.72 and 0.67, 0.83 and 0.77 daily, and 0.49 and 0.49 degrees Celsius, respectively, for the daytime and night time. The root mean square error of relative humidity for mechanical and natural ventilation was 4.4% day and night, 3.0% for daytime, and 6.0% for night time. After modifying the simulation model, four days of microclimate inside the greenhouse showed that the temperature inside the greenhouse reaches 35 °C during the day and less than 16 °C at night, which are not in the optimal temperature range for greenhouse cucumbers. Due to high temperature (35º C) and low humidity (15% to 30%), evaporative cooling will be required at some hours of the day. The total simulated transpiration was 30.2 mm. The estimated temperature was acceptable, but the estimated relative humidity at night differed from the measured values due to thermal inversion. Estimated transpiration was modified by combining the energy balance model and the Stanghellini transpiration equation. After verifying and modifying the model, the microclimate conditions of the greenhouse were simulated and analyzed for four days. The results showed that by using the energy level model before the construction of the greenhouse, it is possible to estimate the microclimate conditions of the greenhouse and the water requirement of the crop.

In recent years, there has been high attention towards soilless cultivation or hydroponic for growing plants in greenhouses. In the current study we addressed normalized water productivity of lettuce (Lactuca sativa) between soil and hydroponic cultivations and also the assessment of AquaCrop model in simulation of yield and water use efficiency of lettuce cultivation methods. The Normalized Water Productivity is used for simulating plant growth in AquaCrop model. The experiments on two mentioned cultivations were conducted during two cultivation periods. The first cultivation’s data were used for calibrating the productivity parameter of normalized water and the second’s cultivation data were used for validation. The obtained results suggested that the productivity parameter of normalized water was different for soil and hydroponic cultivations, it was 14.3 and 15.8 g m-2, respectively for the two cultivation types. AquaCrop model was performed using these amounts for second cultivation period and the value of biomass was simulated during growth period and then was compared to the measured values. The results indicated that AquaCrop model simulated the performance of lettuce with a suitable accuracy during growth period using the calibrated values of normalized water productivity. Water use efficiency (WUE) was also measured and simulated in both cultivation periods for hydroponic and soil cultivations. The results indicated that the water use efficiency (WUE) in hydroponic is higher than WUE in soil cultivation. Also, the amount of canopy cover was measured for both culture mediums in both cultivation periods and was simulated by the model and the results showed that the model simulates the amount of canopy cover well for both culture mediums. Also AquaCrop model has higher accuracy in the simulation of performance and WUE for lettuce. According to the obtained results, it was concluded that the culture medium influenced the performance of lettuce plant; and performance and WUE in hydroponic cultivation is higher than soil cultivation. Furthermore, AquaCrop model has relatively high accuracy in the simulation of performance, WUE, and also simulation of canopy cover for lettuce plant.

Reference evapotranspiration (ETo) is one of the most critical parameters in proper design of irrigation systems. Accurate estimation of ETo leads to reduction of water losses. Due to the ability of Artificial Neural Networks (ANNs) in computational analysis of complex processes, the main objective of this study was to investigate the sensitivity of the ETo trends to key climatic factors in Tehran province using the artificial neural networks, and compare it with the ETo-calculator software results. The ETo was calculated using meteorological data (10-year data of 12 meteorological stations in Tehran province) using the ETo-calculator software. In order to model ETo, a set of inputs to artificial neural networks including the minimum and maximum air temperature (Tmax and Tmin), the minimum and maximum relative humidity (RHmin and RHmax), sunshine hours (n), and wind speed (U2) were considered. After data tagging, by optimizing the number of hidden layers and network algorithms, output values were estimated. The results indicated that artificial neural network is a suitable technique for ETo analysis(R^2≅98% ). The best model for estimation of ETo is feed-forward Multi-Layer Perceptron (MLP) with two hidden layers in its structure (6-11-14-1), Levenberg–Marquardt training algorithm for both hidden and output layers and Linear Tanh and Tanh transfer functions for hidden and output layers, respectively. The sensitivity analysis of the model for input parameters showed that the optimal artificial neural network model and ETo calculator software have the same trend and the Tmax and n are the most effective and least effective parameters in ETo estimation, respectively. Also, based on PCA analysis results the scenario of using of four parameters (Tmax, Tmin, RHmax and U2) as the only inputs to the selected artificial neural network, can estimate ETo with an acceptable accuracy〖(R〗^2≅94% ).

Not only urban development and consequently the need to increase the green space, but also the shortage in water resources, the need for optimal allocation of water to different demands, and limited information of urban green space make a necessary to determine the crop coefficient and water requirements of green space species. The factorial experiment aimed to investigate the evapotranspiration (ETc) and crop coefficient (Kc) of Cercis siliquastrum L. with two factors of soil texture (clay loam and sandy loam) and drought stress (0.3, 0.5, and 0.7 of MAD) based on a completely randomized blocks design (CRBD) with 10 replications in the climatic conditions of Karaj during 2019-2020. Our findings indicated that 10-day ETc under 0.3, 0.5, and 0.7 MAD were 15.56, 14.86 and 14.24 mm in clay loam and 21.57, 19.02 and 18.06 mm in sandy loam soil, respectively. The ETc increased with progressing in drought stress (from 0.7 to 0.3 MAD) in both clay loam and sandy loam soils. The total net water requirements of Cercis siliquastrum L. in clay loam soil under 0.3, 0.5 and 0.7 MAD were 45.15, 388.58 and 381.41 mm, respectively, and it was recorded as 353.02, 317.59 and 290.54 mm, respectively, in sandy loam soil. The mean Kc of Cercis siliquastrum L. during the growing period in clay loam soil under 0.3, 0.5, and 0.7 MAD were obtained to be 0.36, 0.32, and 0.31, respectively. In sandy loam soils, this value was determined as 0.27, 0.26, and 0.24 under 0.3, 0.5, and 0.7 MAD, respectively.

In the current water crisis, the use of springs has helped to mankind in many areas. The application of indexes and statistical methods provide useful information for understanding water quality and planning for its proper management. When water resources have unique characteristics in addition to conventional use; this issue becomes more important, including the river, hot springs and Dehloran bitumen springs. In this study, 28 samples of hot spring water, 4 samples of river water and 4 samples of bitumen spring water were collected. The temperature, pH, EC, sodium, potassium and nitrate parameters were measured. One-way analysis of variance and one-sample T-test were used to compare the three regions and compare with WHO standard and Iranian national standard, respectively. Wilcox, WQI and INWQS indices were also used to classify water quality. Based on the results, bitumen spring water had a statistically significant difference with the other two regions in terms of all parameters and all parameters in the three regions had a statistically significant difference with WHO standards and Iran's national standard and lower than these standards. According to the Wilcox index, all specimens were unsuitable for irrigation; based on the data of the WQI index calculation, water quality can be classified as excellent quality and according to INWQS in terms of pH for aquaculture of sensitive species do not need treatment and in terms of nitrate are only suitable for irrigation. Considering the management and protection of the region as a national natural monument, it seems that the role of natural factors such as geology and the occurrence of floods in the chemical composition of water resources is much more important and based on the results of used methods with the exception of Wilcox index, the water quality was assessed as suitable. However, considering the health use of hot springs and the possibility of constructing welfare facilities for tourists, the role of human factors on the water quality of resources in the region should not be overlooked.

The purpose of this study is to investigate the effect of meteorological drought on groundwater resources in Varamin plain. For this purpose, the effect of meteorological drought was investigated through standard precipitation index (SPI), NISTOR index and groundwater source index (GRI). Therefore, in order to evaluate the effect of climatic parameters such as temperature and precipitation on the groundwater status of Varamin plain, time statistics (1367-1397) of the parameters of the plain were used. The results showed that according to the SPI index, this plain is approaching weak drought conditions during the last 10 years of the study period. Therefore, due to the lack of natural food sources of the aquifer in recent years (since 1388), accidental falls have occurred in this aquifer, which has led to the GRI index from normal drought conditions to relatively severe drought conditions. Finally, the results of SPI and GRI index were compared with NISTOR index, which is obtained from the inferential matrix of the combination of Di-Marton climate index and effective precipitation. This index also assessed the effect of drought and rainfall nutrition index on groundwater resources in the desired period as very severe.

Today, changing the pattern of planting towards water deficit resistant plants is proposed as a solution to drought. One of the plants resistant to drought is roselle. In this study, the effect of different levels of irrigation water and potassium fertilizer on roselle was investigated. Experiment with split plot design with four levels of irrigation water (I1, I2, I3 and I4 equivalent to 40, 60, 80 and 100% water requirement) three levels of potassium (K1, K2 and K3 equivalent 50, 75 and 100% potassium requirement) as sub-plot. At the end of experiment, parameters of dry yield and irrigation water productivity and Qualitative parameters of anthocyanins, proline, carotenoids, chlorophyll a, chlorophyll b and carbohydrates were measured. The results showed that the simple effects of irrigation water and potassium fertilizer were significant (P <0.01) on all measured parameters. The highest yield was obtained from 100% potassium fertilizer treatments and 80% water requirement. The highest irrigation water productivity was obtained in 60% water requirement and 100% potassium fertilizer application but no significant difference was found between 60 and 80% water requirement. In terms of quality, the amount of anthocyanins, carbohydrates and proline increased with decreasing the depth of irrigation water to 60% of the plant's water requirement and reducing the consumption of potassium fertilizer, and the amounts of chlorophyll a and b and carotenoids decreased. However, there was no significant difference between 50 and 75% K fertilizer application. Therefore, due to the water status of the region and the reduction of water resources, 80% water requirement reduces water consumption and 75% potassium fertilizer increases quality and mitigates drought stress in roselle. Also, due to the dry climatic conditions of Sistan region, the use of potassium fertilizer can reduce the damage caused by drought stress in roselle.

Poor drainage system in paddy fields with heavy texture soils not only makes it difficult to harvest rice mechanically at the time of rainfall, but also the use of non-conventional Waters (drainage water reuse) or increased salinity of irrigation water in long-term solute accumulation Soil and its sodification. Also, such lands are not able to eliminate the conditions of waterlogging in wet season and limited the second crop cultivation. Therefore, to avoid salinizing and remove the waterlogging problem in paddy fields the construction of drainage system is necessitated. Installation of subsurface drainage in sand and gravel trench results in better porous conditions around the drainage pipe and thus improves drainage efficiency. Selecting the optimum trench geometry from a technical and economic point of requires simulation abilities. In this study, HYDRUS-2D simulator model was used to evaluate the performance of trenched subsurface drainage with sand and gravel envelope in paddy fields. In order to calibrate the HYDRUS-2D model, a physical model of controllable trenched subsurface drainage was constructed in paddy fields and the rice plant was cultivated in its tank. In the growth period, soil solution in various depths and distances from drain and the drain water of mid and end season drainage was sampled. The electro conductivity (EC) of samples were measured in laboratory. Simulation results showed that the model has a good accuracy in simulating water movement, total dissolved solid of drain water and solute of soil solution. R2, RMSE and nRMSE in water movement validation were obtained 0.982, 2.8 cm and 4.55 percent, respectively and in the solute transfer validation stage part were obtained 0.419, 0.035 mg/cm3 and 10.56 percent, respectively. The results of sensitivity analysis also showed that soil saturated hydraulic conductivity parameters and longitudinal diffusivity coefficient with sensitivity coefficient of 2.6 cm/day and 0.47 cm had more effect on water and solute movement respectively.

In this study, the water-use zoning (ETC) of wheat, barley, potato, sugar beet, onion and alfalfa crops obtained from CROPWAT 8.0 model using ArcGIS 10.3 software and data from 21 synoptic meteorological stations in the Urmia Lake basin has been at 2013-14 and 2014-15. At First, the average ETC values were estimated using climatic data, longitude and latitude, meteorological station height, soil and crop in the two years and then in the whole basin zoned and classified. Overall, the results showed that the rate of evapotranspiration was different across the basin, which indicates the effect of weather conditions in different areas of the basin on the value of evapotranspiration. Investigations also showed that the difference in water demand obtained from meteorological station data between the years under study is significant and the number of meteorological stations in the region can improve the diversity of water needs of the major crops in the region. Surveys of climatic parameters in the studied stations showed that in the areas where the highest rate of evapotranspiration was obtained, it was often with low relative humidity and higher temperature. Due to the problem of water scarcity, accurate estimation of water-use of crops in different areas can be decisive for water consumption in agriculture. Therefore, it is necessary to consider climatic differences in estimating evapotranspiration and irrigation requirement of agricultural crops for sustainable management.

Although pomegranate is one of the major horticultural products in Iran, little research has been done on its irrigation management. In order to investigate the effect of irrigation management on the yield and productivity of 'Rabab-Neyriz' pomegranate trees, an experiment was conducted in one of the pomegranate orchards of Kazerun city in Fars province. Experimental treatments included irrigation at different amounts of available soil moisture depletion at 35, 50, 65 and 80%. A treatment that was completely irrigated by the orchard owner was also considered as control. The experiment was performed in a randomized complete block design with three replications. Soil moisture was measured in different treatments with gypsum block moisture meter. After the soil moisture reached the desired limits, the required amount of irrigation was applied to bring the soil moisture to the field capacity. The orchard was equipped with drip irrigation system and the amount of irrigation water was measured by calibrated flow meters. The experiment was performed for two years and the amount of water used, the yield and water productivity in different treatments were estimated and evaluated by comparing the average values. By measuring the temperature of plant canopy and other required meteorological parameters, the upper and lower stress baselines were extracted by Idso method. Economic analysis was also performed by estimating cost and revenue. The results showed that with the increase of the total water to 19580 cubic meters per hectare (control), the amount of crop yield also increased to 36 tons per hectare, while at soil moisture depletion of 35%,the total used water was 10511 cubic meter and the yield was 28 tons per hectare.The total water productivity in different treatments varied from 1.82 to 3.08 kg / m3, which decreased with increasing the applied water. Differences in water productivity and yield between the 35 and 50% moisture depletion treatments were not statistically significant. Economically, the best treatment for irrigation was the 35% moisture depletion that according to the previous studies, it can be considered as the beginning of water stress in the pomegranate tree. The lower and upper stress baselines obtained in this study, which has not been reported in previous studies, can be used as a tool to manage the irrigation of pomegranate trees in the study area and other similar regions. Therefore, in general, the best treatment of experiment was irrigation at 35% soil moisture depletion. In low water areas up to 50% soil moisture depletion also brings good results.

Unsustainable application of groundwater in the north of Sahand (East Azarbaijan, Iran) caused a decline more than 14m in water level from 1983 (1362) by now. Therefore, the optimum and sustainable utilization of this resource is a management necessity which is depending on modeling, trend analysis and future study of its how application. The present study was conducted with the aim of groundwater level analysis in the north of Sahand with time series, regression and neural-fuzzy inference system methods. The modeling, test and future studying were made for 50 years which 35 years (from 1983 to 2018) were applied to model and test; and 15 years (from 2019 to 2033) were applied to future study. Results showed that based on indices of performance evaluations, neural-fuzzy inference system produced more precise than other methods to analyze groundwater levels. The groundwater level declined more than 14m with an annually of 40cm and its will be 20.03m in 2034 with current conditions of applications of groundwater. Some conservational scenarios are recommended to improve consumption patterns for groundwater resource in this plain.

Microbial pollution is one of the most important type of water resources pollution as associated with the health of animal and human. In this study, E. coli retention under deficit irrigation conditions and presence of preferential flow was investigated using column study Soil. The irrigation levels were T120, T100, T80, and T60% of field capacity and the number of irrigations were five. The one preferential flow was artificially created in the middle of the soil columns. Cells were injected from top of the soil surface. The number of bacteria after irrigation in different layers was monitored. The results showed that by reducing the irrigation level from 120 to 60%, bacteria transport decreased within the soil profile. The highest accumulation of bacteria was observed on the soil surface. In the T60 treatment, about 90% of the retention was at a depth of 10 cm.Therefore, deficit irrigation, could limit bacteria movement within the soil profile so that may result in less surface water contamination. Preferential flow, caused greater retention of bacteria in the vicinity of matrix as compared to the control columns. The bacterial retention in the vicinity preferred flow state at a depth of 10 cm of soil surface layer was about 45% and 28.5% higher than the treatment similar to them in the non-preferential flow state

Many farmers plant rainfed wheat in Mazandaran province that produces lower yield than irrigated wheat. Therefore, in this study, effects of supplemental irrigation in sensitive growth stages accompanied with the split application of nitrogen on yield and qualitative characteristics of wheat (Morvarid veriety) was studied in Pahnab station (Sari). This study was carried out as Complete Random Blocks Plot in split plot with four replications in 2015, 2017 and 2018. The main treatments included A1= irrigation on flowering, A2= irrigation on grain filling, A3= irrigation on flowering and grain filling and A4= rainfed (control treatment). The minor treatments included B1= 200 kg/ha urea application and in four splits (25% before planting, 25% at tillering, 25% at stem extension and 25% at booting) and B= 250 kg/ha urea application and in five splits (25% before planting, 25% at tillering, 25% at stem extension, 25% at booting and 25% at flowering). The considered characteristics were protein percentage, 1000-grain weight, the number of spikelet in spike, infertile spikelet and spike length. Analysis was conducted by SPSS and showed that in every three years, irrigation was effective on 1000-grain weight, protein percentage and infertile spikelet in significance level of 0.05 and the best treatment was A3 that resulted 25% increase in protein, 8.5% increase in 1000-grain weight and 22% decrease in infertile spikelet. For one irrigation, the best treatment was irrigation in grain filling for improving 1000-grain weight, protein percentage and infertile spikelet. For spike length and number of spikelet in spike, results showed that supplemental irrigation and fertilizing had no significant effects. For fertilizing, urea application on flowering had significant effect on 1000-grain weight in every 3 years and on the number of spikelet in spike in 2 years in significance level of 0.05; however, had no significant effects on others characteristics. In addition, there was a significant effect of the interaction between irrigation and fertilization in 2 years on protein percentage. Based on results, the best irrigation treatment is (A3) irrigation on flowering and grain filling and the best fertilization treatment is 250 kg/ha urea application in 5 splits.

It is much easier to measure solid phase data or particle size distribution than soil water retention curve, some researchers use the similarity between the shape of particle size distribution and soil water characteristic curve. One of the soil water characteristic curve is the Aria and Paris model. The Aria and Paris model is a physical based model that is widely used to obtain the soil water retention curve. In this model, the particle size distribution curve was divided into n separate fractions, which the diameter of each fraction is equal to the mean of the upper and lower limit diameter. This model usually uses arithmetic average. In this study, the effect of arithmetic mean, geometric and harmonic means as the mean radius of solid particles in different soil textures and suctions were investigated. For this purpose, 19 soil samples in SiStan regoin with sandy, sandy loam, loam, silty loam and clay textures were evaluated. In coarse soils such as sandy and sandy loam, the best results were obtained when the harmonic mean was used In the loam and silt loam soils, the best results were obtained when geometric average was used as the mean diameter of the different fractions .In clay soil, the best results were related to arithmetic average. In general, it can be concluded that using the different methods of means the accuracy of Aria and Paris models increases in estimating the water content.

Pistachio production in Iran has a long history. Iran's pistachio quality is unique among the world's producing countries. Increasing water productivity for this strategic product is essential. The water consumed for pistachio in Iran has not been determined. In some parts of the country, researches have been carried out and quantities for pistachio irrigation water application are reported. In order to measure irrigation water application of pistachio under farmers conditions and compare it with water requirement and the national document, this research was conducted from October 2016 for one growing season in some gardens of Khorasan Razavi, Semnan, Kerman and Yazd provinces. In these provinces, 88 gardens were selected and in each of them, irrigation water application (without intervention in their irrigation program), yield, water productivity, and some other parameters were determined. The results showed that water consumption and water productivity in the studied provinces were significantly different. The yields of the gardens of the four provinces were close to each other. The average yield of pistachio, irrigation water application and water productivity were 1764 kg/ha, 8057 m3/ha and 0.26 kg/m3, respectively. The results showed that the amount of water application in all pistachio gardens were less than the nete irrigation water requirement.

Optimal use of available water resources and their management is very important according to modern science. This has led to the importance of using plant models to study the effects of low water on agricultural yields. In order to investigate the effect of moisture stress on yield and growth traits in three cultivars of horizon, clear and narin and weeding and validation of vegetative model AQUACROP for these cultivars were performed in 96-97 crop year on a research farm located in Birjand. The research was conducted in the form of a factorial randomized complete block design with 6 treatments and three replications. Irrigation treatments included 100 (control treatment), 75 (medium stress) and 50 (severe stress) percentage of wheat water requirement and 3 other treatments related to two new cultivars of Ofogh and Narin and one old and native cultivar Roshan. The results of the mean comparison of the mean mean of the simple effect of moisture stress, the simple effect of cultivars and the interaction effect of stress on different cultivars were significant in different traits. After analyzing and comparing the average plant traits of the AQUACROP plant model for stresses of 100 and 75%, the water requirement was measured in two parameters of grain yield and biomass. After the validation stage, the model validation model was performed with 50% water stress. The results of the model validation showed that the model calculations showed a close and acceptable simulation value compared to the measured value of grain performance according to NRMSE and R2 evaluation indicators. Also, to ensure the accuracy of the model, using the measured performance data, the bright figure in the 2009-2010 crop year was validated by changing the re-meteorological data. The NRMSE index value of the simulated and measured grain mass for the mean moisture stresses of 100 and 75% in the horizontal and horizontal digits of Rosin, Narin and Narin cultivars was 0.99, 0.88 and 1.51%, respectively. These values were observed in the model validation in 50% stress to 1.49, 3.14 and 0.88%, respectively. According to the values calculated in the statistical indicators, it can be concluded that the model can provide us with an acceptable efficiency for measuring different wheat cultivars, which is very important in the region due to the high and increasing number of different wheat cultivars.