فرزاد حسن پور

Intake canals of off-stream reservoirs, play a key role in achieving reservoir goals. Chahnimeh reservoirs have been constructed to store and use water optimally for drinking, agricultural development and play a complementary role to flood control. The Sistan plain in the southeast of Iran is highly dependent on surface water resources. The HEC RAS model is a well-known one-dimensional software for flow and sediment simulation. In this study, HEC RAS 6.0.0 was used to simulate sedimentation in feeder 2 canal under maximum conditions as well as minimum water level conditions of Chahnimeh reservoirs. Flow simulation in the model was performed quasi-unsteady using the standard step-by-step method by a flood hydrograph with a volume of one billion cubic meters. According to the simulation results, in maximum water level Conditions, Feeder 2 canal Sedimentation volume is equal to 54,200 m^3 which increases the bed level by 4.1m. Also, in minimum water level Conditions, sedimentation is equal to 52,700 m^3, which increases the bed level by 3.84 m. Comparison of the results in the two scenarios shows that in the case of maximum water level, volume of sediment per unit of length of Sistan River is equal to 6.5 m^3⁄L_River while in minimum water level volume of erosion is equal to 2.2m^3⁄L_River of Sistan River. Although feeder 2 canal in minimum water level conditions increases the inflow from the Hirmand river due to the decrease in the river bed level of sistan river but will act as a sedimentation canal in all conditions.

This study aimed to estimate the spatial distribution of soil properties including field capacity (FC), permanent wilting point (PWP) and  total available water (TAW) using ordinary kriging (OK) and random forest (RF) in agricultural lands of the southern Sistan Plain, covering an area of approximtely 147000 hectars. FC, PWP, and TAW and soil texture components were measured for a total of 200 surface soil samples (0-30 cm). Performance evaluation of the two methods based on the percentage of normalized root mean square error (nRMSE) revealed that the conventional OK with 5% less error in estimating FC, 3% less error in estimating PWP, and 5% less error in estimating TAW performed slightly better than RF. Comparing Bias values showed that OK underestimates both FC and PWP and overestimates TAW, while RF overestimates all three parameters. Spatial distribution maps of FC, PWP, and TAW produced by OK model showed that the highest amount of FC (23%) and TAW (14.4%) were in the west and northeast of the region, which had heavier texture and lower altitude from the sea level. In the southern and southeastern regions, which have lighter soil texture, the amount of available water was less compared to the western and northeastern regions. In the RF model, the most important variable extracted from satellite images was Digital Elevation Model  (DEM), and all three features had higher values in areas where DEM was lower. It seems that the flatness of the study area and the inadequacy of auxiliary variables caused the lower accuracy of the RF method.

Correct estimation of the river sediment volume is important for many water resources projects.In this study, the empirical equations of sediment transport, support vector regression (SVR), and developed k-nearest neighbor regression (KNN) were used in order to estimate suspended sediment load in the Sistan River. In this regard, in addition to the maximum temperature, minimum temperature, and dischargeand Suspended Loud In the period 1374 to 1390, it was paired on 1682, discharge, the classified discharge was used as effecting variable to suspended sediment load modeling. For each of the input combinations in support vector regression and development k-nearest neighbor regression the best structure of the regression model determined based on the performance criteria. The Result showed that the Toffaleti method is the best method between empirical equations with R2 equal to 0.705 and RMSE equal to 66558 Ton/day. Also, the support vector regression model with discharge, minimum temperature, maximum temperature and classified discharge as the set of input data is the best model in estimation of suspended sediment load with R2 equal to 0.96 and RMSE equal to 2809.3 Ton/day. The results indicate that the regression method estimate suspended sediment load much better than empirical equations in the Sistan River.

Today, maintaining the quantity and quality of irrigation water are the most critical challenges in the agriculture system, especially in arid and semi-arid regions of the world. Accordingly, to evaluate the growth and yield responses of bread wheat (Sirvan cultivar) to different levels of deficit irrigation and water salinity, a factorial experiment was conducted in a randomized complete block design with three replications in the Research Field of Agriculture Faculty of the University of Birjand, at Birjand (east of Iran) during the growing seasons of 2016-2017 and 2017-2018. The experimental treatments included irrigation at five levels (125, 100, 75, and 50% of wheat water requirement and rain-fed with two supplementary irrigation at the first growing season) and saline water at two levels (1.6 dS/m and 6 dS/m). The results showed that growth characteristics, yield components, biological yield, and grain yield were affected by deficit irrigation water and saline water. These treatments significantly reduced all of the measured traits. The lowest leaf area was observed in rain-fed with 6 dS/m saline water treatment, which suppressed this trait by 61% compared to 125% water requirement with 1.6 dS/m saline water treatment. The highest and the lowest biological yield and grain yield were observed in 125% water requirement with 1.6 dS/m saline water and rain-fed with 6 dS/m saline water treatments, respectively. Non-significant differences were observed in biological and grain yield between 125% water requirement with 1.6 dS/m saline water and 100% water requirement with 1.6 dS/m saline water treatments. Biological yield and grain yield were decreased in rain-fed with 6 dS/m saline water treatment compared to 125% water requirement with 1.6 dS/m salinity treatment by 72% and 88%, respectively. Results of this study showed that although the greatest amounts of yield attributes were obtained upon using the 125% water requirement treatment, but these attributes were not significantly greater than the 100% water requirement treatment. Consequently, in areas with scarce water and saline water (6 dS/m), reliance on the 75% water requirement with 6 dS/m saline water and 100% water requirement with 1.6 dS/m saline water treatments may suffice to achieve an acceptable grain yield and to save water under saline water condition.

Drought is one of the most widespread and devastating phenomenon which has been more frequent due to climate change consequences in recent decades. The aim of this study is to project the agricultural drought in Birjand station, Iran using outputs of five GCM models approved in IPPC fifth assessment report, AR5, namely MIROC-ESM, GFDL-ESM2M, HADGEM2-ES, CSIRO-MK3.6 and IPSL-CM5A-LR under RCP4.5 and RCP8.5 scenarios. The retrieved outputs were downscaled using LARS-WG statistical model for the future period (2055-2025). For monitoring the drought the Self Calibrating Palmer Drought Severity index (SC-PDSI) during the baseline (1975- 2005) and future period was used. The results indicated that occurrence of droughts during future period will increase comparing to baseline, which might be caused by climate change in the study region. Models projections under both scenario revealed that the (2026-2035) period would experience more severe drought comparing to remaining years. According to results, the highest number of drought events in future period was projected by MIROC-ESM and CSIROMK 3.6, models under RCP8.5 scenario.

Salinity and drought stress are the most important factors that limit plant growth, especially in dry and semi-arid regions. To investigate the effects of irrigation water levels and salinity on yield and yield components of wheat cultivar Sirvan, a factorial experiment was conducted in a complete randomized block design with three replications in the research field of agricultural faculty of the University of Birjand during the growing season of 2017-18. The treatments included irrigation at four levels (125%, 100%, 75%, and 50% water requirement) and water salinity in three levels (1.6 dS.m-1, 6 dS.m-1, and 7.8 dS.m-1). The results showed that yield components, biological yield, and grain yield of wheat were affected by water irrigation levels and water salinity. Moreover, these treatment significantly reduced the yield components, harvest index, and water use efficiency (WUE). In biological and grain yield of wheat, the highest and the lowest amounts belonged to 125% water requirement × salinity of 1.6 dS m-1 by 1535and 588.76 g m-2, respectively. In biological yield and grain yield, there was no significant difference observed between 125% wheat water requirement × salinity’s of 1.6% dS.m-1 and 100% water requirement × salinity of 1.6% dS.m-1 treatments. Biological and grain yield of wheat decreased to 65% in 50% water requirement × salinity of 7.8 dS m-1 compared with 125% water requirement × salinity of 1.6% dS.m-1. According to results of this experiment, 125% and 100% water requirement treatments had the highest biological and grain yield. Although 125% wheat water requirement had the highest value in all traits but they were not significant compared to 100% water requirement treatment. In water salinity treatments, non-stress levels had the best performance. According to the results of this study, to avoid salt accumulation in the root zone under saline water irrigation and to decrease negative salinity effects, irrigation must be applied based on wheat water requirement.

In arid and semi-arid areas, water can be a limiting factor for plant growth and agricultural yields. It is an important input to agricultural production and also an essential requirement for domestic, industrial and municipal activities. Increasing population and standards of living are contributing to a steep rise in demand for fresh water. By using proper irrigation management in farm, we are able to utilize water, soil and fertilizer to produce high yield and quality products. Drip irrigation is considered one of the most efficient irrigation methods. One of the major advantages is its ability to apply water to the soil as often as desired and in smaller quantity than the other irrigation methods. Drip irrigation has been practiced for many years for its effectiveness in reducing soil surface evaporation and it has been widely used in horticultural crops in both greenhouse and open field. Also, deficit irrigation is one of the strategies for efficient use of water and increasing water use efficiency in agricultural district. Deficit irrigation is a suitable solution to gain acceptable and economic performance by using minimum amount of water.

In order to investigate of surface and subsurface drip irrigation systems under soil matric potential on Rosmarinus officinalis L., a field experiment was carried out during 2015 growing seasons at center of seed and plant production of Kerman municipality. The treatments were laid out in randomized complete block design with three replications. The treatments were comprised of three soil matric potentials of 40, 60, and 80 centi-bar for initiation of irrigation in the main plot and sub plot consisted of two drip irrigation systems (surface and subsurface). In this study, surface systems, drip lines were placed on the soil surface at a distance of 15 cm from the plant and subsurface systems, drip lines were placed at a depth of 30 cm. The irrigation time was determined based on the readings of metal Tensimeters. These tensiometers were installed in three depths of 15, 30 and 50 cm of soil and at a distance of 20 cm from the plant. In this regard, in both irrigation systems, a Tensiometer mounted at a depth of 15 cm of soil was used for early growth and growth development, and from Tensiometers mounted at depths of 30 and 50 cm soil, for reading in the middle and final stages of growth. In order to carry out irrigation at the potential point of view, the tensiometers were fully controlled and when the calibrated tensiometer screen showed the desired potential point, irrigation was carried out and the irrigation process continued until the soil moisture reached the crop capacity level. Dry weight, leaf area index (LAI), number of shoots, plant height, water productivity were measured. Data were analysed statistically using SAS Statistical software. Treatment means were compared using LSD test.

The results showed that in comparison to 40 and 60 c-bar tension, parsimony of water usage equal 44.6 mm (21.7 percent) achieved. Moreover dry weight, number of shoots per plant and height of plant decreased 12.5, 12.8 and 11 percent respectively but water use efficiency increased 10.5 percent. Moreover dry weight in subsurface drip irrigation was increased 48 gr.m2 compared with surface irrigation. Also parsimony of water usage equal 10 percent and water use efficiency increased 21.4 percent. Number of shoots per plant and height of plant increased 8.2 and 8.7 percent respectively in subsurface drip irrigation.

According to the results, for Rosmarinus officinalis L. cultivation in Kerman area, application of the 60 centi-bar of soil matric potentials in subsurface drip irrigation system is the best way to increase the water use efficiency for the drought years.

In arid and semi-arid areas, water can be a limiting factor for plant growth and agricultural yields. Considering limited water resources in arid and semi-arid climate of Iran, deficit irrigation is one of the strategies for efficient use of water and increasing water use efficiency in agricultural lands. Deficit irrigation (DI) is a suitable solution to gain acceptable and economic performance by using minimum amount of water. The Partial Root- zone Drying (PRD) irrigation is a new improvement in deficit irrigation in which the half of the root zone is irrigated alternatively in scheduled irrigation events. The plants with PRD irrigation method can, therefore, have different root system in comparison with other irrigation methods. At this method the plant’s condition would be OK by withdrawing water from wet side, and the roots at the dry side can release abscisic acid hormone which decrease the stomatal conductance and consequently the water use efficiency would increase. Also, by using proper irrigation management in farm, we are able to utilize water, soil and fertilizer to produce high yield and quality products. Drip irrigation is considered one of the most efficient irrigation methods. One of the major advantages is its ability to apply water to the soil as often as desired and in smaller quantity than the other irrigation methods. Drip irrigation has been practiced for many years for its effectiveness in reducing soil surface evaporation and it has been widely used in horticultural crops in both greenhouse and open field.

In order to compare two deficit irrigation methods on plant growth characteristics of Rosmarinus officinalis L., a field experiment was carried out during 2016 growing season at an experimental farm in Kerman Municipality seedling production station. The experimental treatments were arranged as randomized complete block design with three replications. The irrigation regimes consisted of full irrigation (FI-100), regulated deficit (RDI75 and RDI55) and partial root zone drying irrigation (PRD75 and PRD55). In this study, drip lines were placed on the soil surface at a distance of 15 cm from the plant and plant rows were placed between drip lines. The irrigation interval was 4 days for all treatments. In the full irrigation and regulated deficit irrigation treatments, the plants were irrigated from two sides for every irrigation. In the PRD, one of two neighboring drip line was alternatively used for irrigation. The irrigation interval was 4 days for all treatments. Dry weight, leaf area index (LAI), number of shoots, plant height, water productivity, root fresh weight, root depth and root volume were measured. Since the highest essential oil of rosemary is at 50 percent of flowering time, the above-mentioned indices were measured at the middle of flowering (190 days after planting) by removing the side rows in each replicate and half a meter from the beginning and end of each row. As a marginal effect, 10 plants were randomly selected and sampled from two middle rows, each replicate of each treatment. The harvested bushes were dried at 25 °C for three weeks and then the dried weight of the vegetative organs was measured. Moreover, the number of 10 plants selected from each treatment was accurately counted to determine the number of shoots. Data were analyzed statistically using SAS Statistical software. Treatment means were compared using LSD test.

The results showed that highest herbage dry weight (145.3 g) and leaf area index in different stages of growth were under full irrigation treatment in which no significant difference between this treatment and 75 percent water replacement in partial root zone drying was observed. The highest number of shoots (128.7) and plant height (68.4 cm) were also obtained by full irrigation treatment and there was significant difference between this treatment and other treatments. However, the highest water productivity (2.06 kg/m3), root fresh weight (3.8 g), root depth (16.4 cm) and root volume (2.4 cm3) were found in 75 percent water replacement in partial root zone drying.

According to the results, 75 percent water replacement in partial root zone drying irrigation treatments, in addition to saving water consumption, provides better use of soil moisture and sunlight. Thus, this treatment can be considered as a suitable approach to cope with the water crisis and achieve a sustainable agriculture.
Keywords: Drip irrigation, Drought stress, Leaf area index, Medicinal plant, Rosmarinus officinalis, Water productivity

In order to study the effects of two drip irrigation systems and deficit irrigation on the quantitative traits of Rosmarinus officinalis L., an experiment was conducted in Kerman Municipality seedling production station in 2016. The experimental treatments were laid out in split plot a randomized complete block design with three replications. The treatments consisted of five irrigation regimes (full irrigation (FI-100), regulated deficit (RDI75 and RDI55) and partial root zone drying irrigation (PRD75 and PRD55)) in main plot and two drip irrigation systems (S1= surface and S2= subsurface) in sub plot. The results showed that applying of subsurface drip irrigation system compared to use of surface drip irrigation, in addition to saving 11.4 percent in water use, increased the water productivity 21 percent. Also, the highest herbage dry weight (4404.2 kg.h-1), plant height (68.4 cm), number of shoots (128.7) and leaf area index in different stages of growth were produced by S2FI. Using S2PRD75 compared to use of S2RDI75, increased all of the Rosmarinus plant growth parameters. However, Using S2PRD75 compared to use S2FI in addition to saving 25 percent in water use, increased the water productivity 12.8 percent and dry weight, number of shoots per plant and height of plant decreased 5.3, 8.9 and 9.8 percent respectively. Simultaneous analysis of Rosmarinus’s water productivity and its growth parameters showed that it could be possible to save in irrigation water use and increase the water productivity with the lowest decrease in the Rosmarinus plant growth parameters by applying S2PRD75.

Drought is a natural and repeatable disasterwhich affects all climates. Because of the intrinsically dry climate and low precipitation in Sistan plain, the main water resources are surface water originated from a neighboring country. This study investigates the relationship between meteorological and hydrological drought in Sistan plain.
At first, meteorological and hydrological drought were investigated by indices including moving average, SPI and SDI in Sistan plain. Moreover, the relationship between them was evaluated for 45 years.
Results show that indices of meteorological and hydrological droughts do not match with each other in the entire of the study period, but there is a significant relationship between them during dry years. It was also observed that a drought period started in 1999 and continued until 2012.
Discussion and Therefore, due to low volume and high coefficient of variations of rainfall and vital role of surface flows in the supply of water in the plain, hydrological drought shows conditions of drought is better than the meteorological drought in Sistan plain.

Hirmand River is the main drainage system in the southern part of Afghanistan and has a significant impact on the socio-economic life of Sistan region. The assessment of water potential of Hirmand River is essential for long term period, which requires the use of rainfall-runoff model. The present study focuses on simulating the daily discharge of the upper Helmand basin of Afghanistan using the conceptual model FLEX in combination with multi-objective optimization, which has not been considered in previous studies. At first, the discharge was evaluated integrally by lumped model considering one objection function. Then it was simulated using semi-distributed model by adding the logarithm of the flow to the objection function. The results of this study indicates that the model is efficient in the semi-distributed mode by using two objection functions for calibration of parameters. The coefficients of NS, NS-log in the calibration and validation period were estimated to be 0.86, 0.92, 0.76 and 0.81, respectively. Pareto front analysis gave the best optimum set for each parameter used in model simulation. The model gives satisfactory results based on monthly calibration and can be used to investigate the drought and climate change research of studied basin.

Using proper irrigation management leads to optimum utilization of water, soil, and fertilizer and production of high yield and quality products. In order to investigate the effect of irrigation intervals and surface and subsurface drip irrigation systems on growth indicators of Rosmarinus officinalis L., a field experiment was carried out during 2015 growing seasons at an experimental farm in Kerman city. The treatments were laid out in split plot using a Randomized Complete Block Design with three replications. The treatments comprised three irrigation levels (I 1 =25, I 2 =40 and I 3 =55 mm evaporation from class A pan) in the main plots, and two drip irrigation systems (surface and subsurface) in the sub plots. The results showed that I 2 in comparison with I1treatment led to 44 mm water saving. However, dry weight, height of plants, number of shoots per plant and leaf area index decreased by 12.9%, 12.6%, 13.6% and 5.3 percent, respectively, while water use efficiency increased 3.6 percent. Also, results showed that water use efficiency, dry weight, height of plants, number of shoots per plant, and leaf area index increased by, respectively, 15.1%, 18.3%, 9.7%, 12.5% and 15 percent in subsurface drip irrigation compared to surface method. Therefore, for Rosmarinus officinalis L. cultivation in Kerman area, application of I 2 in subsurface drip irrigation system is the best way to increase the water use efficiency for the drought years.

Rivers are the main arteries of human life, thus control and proper exploitation of these surface resources require a proper understanding of their behavior and investment in the river improvement. By reviewing and evaluating the projects carried out in this area, their positive and negative aspects can be checked and the obtained results can be used to overcome the projects shortcomings, improve their efficiency and make the future projects more fruitful. Sistan River is the major border river between Iran and Afghanistan and Sistan life depends on it. The length of this river in Iran is about 70 Km. This study attempts to evaluate the performance of Sistan and Zahak diversion dam structures and the structures alongside the river using HEC-RAS hydraulic model. The results show that these structures increase the maximum Sistan flood power transmission in the absence of these structures from 500 m3/s to 810 m3/s. Considering the importance of estimating Manning roughness coefficient with high precision for hydraulic calculation in the river engineering projects, the main river bed roughness coefficient for the main river and the flood plains of Sistan were estimated as 0.02 and 0.035, respectively. It was also found that Discharge-Return period relation can be expressed as. Existence of diversion dam structures on the unpredictable rivers such as Sistan River may double the flood power transmission in some cases. In this study, the effect of 310 m3 per power transmission increse through Sistan River was observed. The reasons for the relatively low impact (the xpectation was more) are slight slope of Sistan plain, and water expansion on flood plain and back water in the direction of Sistan River flow.

In order to investigation the root distribution and plant growth of Rosmarinus Officinalis L., an experiment was conducted in a completely randomized design with three replications under using subsurface irrigation system in 2016. In this study treatments are full irrigation (FI), regulated deficit (RDI75 and RDI55) and partial root zone drying irrigation (PRD75 and PRD55). The results showed that deficit irrigation at 75 and 55 percent of full irrigation resulted in saving 17.1 and 32.6 percent water consumption respectively. Comparison of FI and PRD75 showed that dry weight, height of plants and number of shoots per plant decreased 5.3, 9.8 and 8.9 percent respectively. However, proper development of root in PRD75 increased 12.8 percent of water productivity, 7.3 percent of root fresh weight, 2.7 percent of root depth and 10.7 percent of root volume. Therefore, considering the problems of water scarcity, it is possible to provide PRD75 as a superior treatment and a suitable strategy to cope with the water crisis, to move towards a sustainable agricultural system.

Drought is a natural and continuous climatic phenomenon which usually occurs in all areas of the world, but its characteristics, type and intensity is different regionally. It is also a progressive phenomenon so that its start and end is not clear and its influence intensity is low but, it encompasses more areas compare to other disasters such as flood, earthquake and etc. which is finally caused more losses rather than other disasters. Drought threshold considering spatial condition is different, therefore, point statistics of one station as an index station of each region is useable for removing spatial effects. In this study, by use of a software which is designed for calculating Palmer Drought severity Index, this index is calculated and presented for Birjand synoptic station during 1985-2014 statistical period in annual and monthly scale. Also, drought process is studied by use of Mann- Kendal and Petit statistical test. Spi drought index is also presented and an analysis has taken concerning drought indexes and relative yield of rain-fed wheat crop relationship by use of Birjand rain-fed wheat yield data during foregoing statistical period. While the air temperature and precipitation data were homogeneous, Based on statistical tests, it was identified that the 30-year period is enough for drought monitoring and analysis. Results showed that sudden changes of annual and monthly spi time series are significant at 5 percent and its change point is May 1998. Also, about annual and monthly pdsi index, results indicate that sudden changes of annual pdsi time series are significant at 5 percent and its change point is February 2000. Spi and pdsi indexes also had a trend consistent with the relative yield crop index of rain-fed wheat and after change point; the pdsi index correlation coefficient was obtained for rain-fed wheat relative yield equal to 0.7 and the spi index correlation rate for rain-fed wheat relative yield equal to 0.55.

Sedimentation on the rivers beds causes many difficulties not only for an orderly and sustainable flow of water, but also by altering the river's hydraulics, which in certain cases drastically changes the flow direction by opening new channels that inundate farm fields, municipalities and infrastructures. As various models developed for the suspended load (SL) estimation are often site specific, therefore, it is prudent to test and calibrate them for the intended river. As the Hirmand River is the lifeblood of Sistan, therefore, the 70 km terminal reach, the Sistan River, was selected for this project. The monthly and seasonally discharge of the river and its SL contents for the period 1970–2015 were analyzed statistically using six models, namely: linear, double-linear, mean value, FAO, parametric factor and non-linear. As the determination of the break point is very important in the application of the double linear method, the genetic optimization algorithm was used in this process.Two criteria for choosing the correct method for estimation of the SL were used: relative mean error and root mean square error. It is concluded that the double linear method proposed in this research gives the best result in all forms without any delineation, seasonal and monthly classification with the relative mean error of 154.46, 142.7 and 116.15, respectively. Monthly classification of data increased accuracy and reduced the root mean square error in the Sistan River

Most of lands in Kerman province are become saline and sodic, due to large amounts of salts in irrigation water sources. This is considered as one of the major limitations in the production of horticultural crops especially pistachio in recent years. The target of this study was investigation of the effect of different amendments of saline-sodic soil amelioration. Here, the effect of four treatments consist of irrigation water (control), gypsum, saturated gypsum and sulfuric acid was conducted four times in the laboratory condition based on CRD, using the soil column. Columns leaching was carried out intermittently and twice as much as the depth of the soil. Gypsum powder was completely mixed with the surface soil before starting leaching. Sulfuric acid and saturated gypsum were solved in irrigation water in separate containers. Changes in solute salt in drainage water from soil columns showed that the maximum amount of salts were removed from soil columns in the beginning of leaching and by continuing leaching process, reduced nonlinear to the constant concentration. There was no significant difference between gypsum and saturated gypsum treatments in sodium leaching, and these methods reduced the efficiency of leaching up to 30–40 percent. In the contrary, in presence of sulfuric acid the amount of sodium leached out of soil profile almost equaled that of the control treatment. Among all treatments, control treatment removed less amount of calcium and there for its remaining amount of calcium in the soil was more than other treatments. While in control treatment the amount of total removed salt was the highest. During leaching process, SAR changes in drainage water largely reflected the sodium changes and irrigation water compared to other treatments, as a control treatment with the highest amount of sodium removal, had the highest drainage water of SAR. Therefore, due to the great reduction in total salt, sodium leaching and no significant difference between control treatment’s pH and others treatment’s pH, it could be concluded that using irrigation water without application of amendments, plus considering economic issues, was a suitable strategy in successfully reducing both salinity and sodicity of the soil profile. On the other hand, due to the problem of water crisis in this region and removal of about 75% and 50% salts and sodium respectively at the beginning of leaching, irrigation water up to 1.1 times of soil depth can be recommended for the leaching of soluble salt from soil profile in this study area.

The scarcity of freshwater and increasing water demand for irrigation has led to the application of new irrigation methods and also use of saline water resources. For this purpose, a field study was conducted in two crop seasons (2014 and 2015) for evaluating the effect of quantity and quality of irrigation water on morphological attributes and quality of sunflower in the experimental farm of Sari Agricultural Sciences and Natural Resources University. Treatments were arranged as factorial based on randomized complete block design with three replications. treatments included full irrigation with fresh water (FI), full irrigation with saline water (SI), full irrigation with alternative use of saline water and fresh water (FSI), partial root zone drying irrigation with fresh water (PRD1), partial root zone drying irrigation with saline water (PRD2) and partial root zone drying irrigation with alternative use of saline and fresh water (PRD3). Saline water with an electrical conductivity of 5.4 dS/m was obtained from 20 percent mixing of Caspian seawater with fresh water. The results showed that, in most morphological characteristics, significant difference was not found between the treatments of PRD1, PRD3 and FSI compared with FI. The highest oil content (56%) was obtained from PRD2 and PRD3. SI treatment had the lowest oil content. The maximum oil yield was found in treatments FI and PRD1 with amounts of 1831 and 1783.5 kg per ha, respectively. The lowest level of oil and protein yield was found in PRD2 and SI treatments in both years. It could be concluded that in the water crisis condition and the need to use less water or saline water instead of fresh water, PRD3 and FSI methods are recommendable as the optimal management.

Residential and urban development in margins of rivers and floodplains have Changed rangeland and agricultural land toresidential and industrial land then the hydrological behavior of watershed has been unusual. In this study, the behavior of urban flood of Birjand in the shahroud watershed was studied. The shahroud watershed has hada lot ofnon-expert land use change in recent years. In this way initially runoff curve number of SCS model was determined using satellite images, land use and field visits. In the continue, flood discharge was simulated using HEC-HMS model after surveying geometrical characteristics of the main river and its hydraulical structures such as bridges. The results of the simulation show that 25 and 100-year return period leading to the occurrence of peak flood discharge amount of 207.63 and 463.56 cubic meter per second respectively.Results of the simulated flood with a return period of 25 years show that this flood is maximum flow that cross sections and hydraulical structures of the river are able to cross, So in order to reduce the risks of flooding in the city of Birjand more attention to the increased potential for flood passing is essential.

Poor performance of irrigation and drainage networks causes to reduce the transfer and distribution throughputs and in result comes useless water and makes too much consumption in forming. A significant portion of water losses in irrigation and drainage networksis related to transmission and distribution. Therefor more consideration in thrirrigation network management, improve irrigation efficiency and also the exploitation of water resources, especially in the agricultural sector is necessary. Controlling and adjusting structures of water level in the direction of drainage and irrigation canals can influence on increasing of throughput and decrease the use of water. So, right choosing and recognition of the deficiencies of these structures helps carry up the throughput of the networks and prevents to waste water. It is hard to solve equations of water flow in canals and related institutions by using analytic methods. For this reason, this research was done with HEC-RAS hydraulical model in the main channelof irrigation and drainage network of Sistan plain.
Sistan plain is located in southeastern of Iran with good potential for agricultural production because of the alluvial sediments from Hirmand River. 23820 ha of the Sistan plain is covered by 5 blocksof the Shibab irrigation and drainage network. While Sistan’sShibab irrigation network efficiency is low, HEC-RAS Hydraulics model in unsteady condition was performed to control and adjust this network’s main canal in approximately 19 Km length. In this research, the evaluation model in the canal was performed for more suitable intakingwater in the quadruple order 2 canals . So, the existing structure’s operation was analyzed on controlling structures in management and lack of management situations.This research was assessed during a 15-day impounding period using hydraulic model of HEC-RAS with the aim of performance and operation evaluation of existing structures on the Shibab main canal. HEC-RAS model was prepared by United States army corps of engineers which is developed by the hydrologicengineering center.HEC-RAS analyzes river system and runs under the Windows operating system. This software package is of hydraulic analysis program series, where the user communicates with the system via a graphical user interface (GUI). The system is capable of performing steady and unsteady flow water surfaceprofile calculations. HEC-RAS software is designed to perform one dimensional hydraulic calculation for a full network of natural and synthetic channels. Visits were made before and after the beginning of irrigation, and during the Operation, in order to record the data of the flow and observe the way of utilization of canal, and existing structures. Then, the model was calibrated on the basis of depth and discharge measurement and simulation data in real condition of operation for 10 days impoundment during 21 to 30 April, and the Statistical parameter values:RMSE, EF, MBEand R2 were calculated. Then the objective functionwas evaluatedusingoperational performance indexes of adequacy, efficiency, equity and reliability of Molden and Gates regarding to HEC-RAS simulation results in unsteady condition.
According to the simulation results in existing condition,theerror of delivery dischargeis equal to 0.54 while applying the management onthe adjustment structure of irrigation networkdeclined theerror to 0.42. By the canal routstructuremanagement in HEC-RAS model, on the basis of proposed operation option, according to existing operation condition, delivery discharge loss in comparison to the total discharge of the network 0.12 value decreases.Based on the simulation results, the mean percentage of improvementin performance indexes of adequacy,efficiency, equity and reliability, as well as objective functionofdelivery discharge are equal to 19.7, 20.90, 66.07, 65.24and54.81. Therefore based on simulation results of different scenarios and investigation of the effective factors onto the flow, onthe forms of charts and tables show that without management on controlling structures, it isn`t possible to appropriate of flow rate onto second class canals and traditional streams branched out main canal and also streams branched out second class canals, properly.
The results show that the model of HEC-RAS is proper for hydraulic simulation of main canal in the irrigation and drainage network of Sistan plain. Based on the simulation results of different scenarios of this research, the mostimprovements intheobjective functionare allocated toequity and reliability indexes in the Shibab main canal with the proposed management method.

Application of saline water sources combined with reducing water consumption during crops growing seasons will have an important role in adjustment with water crisis. In this regard, applying a suitable water management aimed at sustaining crops under osmotic stress and water deficit can cause food security. Thus, in this research, the influence of partial root zone drying with a combination of sea water on quantitative properties and water productivity of sunflower was investigated in Agricultural Sciences and Natural Resources University of Sari. Treatments were arranged on factorial based on randomized complete block design with three replications. Six treatments included full irrigation with fresh water (FI), full irrigation with saline water (SI), full irrigation with periodic use of saline water and fresh water (FSI), partial root zone drying irrigation with fresh water (PRD1), partial root zone drying irrigation with saline water (PRD2) and partial root zone drying irrigation with periodic use of saline water and fresh water (PRD3). The results showed that significant difference was not found between the treatments of PRD1, PRD3 and FSI compared with FI in yield, harvest index and water productivity. The highest yield with the value of 4706 (kg/ha) in the control treatment and the maximum values of harvest index (%50.63) and water productivity (1.12 kg m3 ha-1) in PRD1 treatment was found. SI and PRD2 treatments had the lowest level of yield with values of 3983 and 3636 (kg/ha), respectively. It could be concluded that in addition to 25 % water saving under applying a suitable irrigation management in PRD3 treatment, it is possible to supply a part of crop water demand with saline water during treatment period which results in higher fresh water saving for sunflower cultivation.

Soil salinity is one of the most important factor which causing a considerable decrease in crop productivity of pistachio orchards in Kerman. In this research, the effects of applying different amendments on reclamation of a saline calcareous soil was investigated by using experimental soil columns. Treatments included: a) irrigation water, b) irrigation water gypsum mixed with soil surface, and c) dissolved gypsum as well as d) sulfuric acid application. Leaching was done intermittently and 2 pore volumes (PVs) were allowed to pass through the soil columns. Based on the results, no significant difference was observed in the concentration of cations as well as EC among different treatments. Application of 1.5 PVs of irrigation water, removed 60% of the total sodium, 70% of magnesium and 70% of soluble salts from the soil column. The cumulative leached Ca2 caused by 2 PVs was very small, accounted for about 4 percentage of total content of Ca2. Application of chemical amendments was not significant on infiltration rate as compared to irrigation water. In terms of water requirement for salt removal from 1 to 1.5 pore volumes, it is recommended that 1 pore volume of irrigation water which efficiently reduced soil sodium and magnesium concentration, soil EC and costs, is the suitable strategy for practical reclamation of the studied soil.

Evapotranspiration is one of the most fundamental parameters in calculating crop water requirement. The parameter is calculated to avoid exposing plants to water stress during different growth stages. In this paper, meteorological data including mean air temprature, mean relative humidity, solar radiation and wind speed from Kavar weather stations in the Maharlu basin and Doroudzan station in the Kor River basin from 1987 to 2011 were used. Calculation have been done using FAOPenman- Monteith method and intelligent techniques including Support Vector Machine (SVM) and M5 models. The results showed that M5 method with R2 = 0.99 and RMSE = 11.377 in the Kavar weather station and with R2 = 0.984 and RMSE = 17.401 in Doroudzan weather station has the best results at estimating reference evapotranspiration. According to the statistical indicators and results obtained in this study, artificial intelligence methods have suitable results in simulationing refernce evapotranspiration. In general, for all modelling scenarios M5 has better results than SVM in estimating reference evapotranspiration using meteorological parameters.

Correct estimation of suspended sediments volume in rivers is one of important issues in river engineering, water resources and environment projects. Sistan river is one of split main branch of Helmand river, which task of irrigate 70% agricultural plain and is responsible for providing part of Hamoon water in Helmand. Given the many problems caused by sediment in rivers, sediment science researchers have done many effort ‌to achieve sediment transport relations according laboratory and field studies. Because of multiplicity parameters involved in sediment transport and complexity process of erosion and transport particles, most of the sediment relationships need to solution complex mathematical equations, however, it aren’t accurate results. Also regression relations between water discharge and sediment discharge aren’t good correlation. Cobaner et al. (2008) is compared the potential of neuro-fuzzy technique with those of the three different artificial neural network technique in suspended sediment concentration estimation. The comparison results shown the neuro-fuzzy models perform better than the other models for the particular data sets (8). Aytek and Kişi (2008) develop an explicit model based on genetic programming. Their research’s results indicated that the proposed GP formulation performs quite well compared to sediment rating curves and multi linear regression models and is quite practical for use (3).

The recent years using of smart systems in order to increase accuracy of estimating of river sediments are common. In this study were used the smart systems‌ including‌ Artificial Neural Networks (ANNs), Adaptive Neuro-Fuzzy Inference System (ANFIS) and Genetic Expression Programming (GEP) in order to estimation of suspended sediment load in Sistan River. Root mean square error (RMSE), mean bias error (MBE) and determination coefficient (R2) statistics are used for evaluating the accuracy of the models.

All smart ways estimate suspended sediment load better than empirical relations. The third scenario of ANFIS from artificial intelligence (AI) methods with RMSE=20983.43 and R2=0.97 is the best result in estimation suspended sediment load. Also AI methods obtained at 95% absent aren’t significant difference between results and according to error rates all AI methods are highly accurate.

According to the obtained results in this study used three methods to estimate the suspended sediment load are suitable but Genetic Expression Programming is preferable to the other two models because of develop a mathematical model. The dramatic impact of the classification of discharge is clear in the precision of the suspended sediment load estimation. According to this research results, suggest estimation of suspended sediment load is suggested using AI methods in Sistan River.