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Stream flow forecast is a fundamental tool that could be utilized for appropriate water resource management. The enhancement of accuracy as well as the increase of time horizon for stream flow forecasts is essential especially for agricultural sector which is the most vulnerable sector during water shortages. In this regard, the application of stochastic approaches like Ensemble Streamflow Prediction (ESP) procedure for long-term forecast with respect to streamflow uncertainty can be proposed. The ESP procedure produces streamflow forecasts in the form of multiple hydrographs, each a possible realization of seasonal streamflow (Day, 1985). One example of ensemble streamflow forecasts is the National Weather Service’s ESP procedure. Faber and Stedinger (2001) successfully combined reservoir operation models with updated information from ESP of the National Weather Service (Faber and Stedinger, 2001). Using ESP forecasts, Eum et al. (2011) also developed a procedure to calculate optimal water release curtailments during droughts using a future value function derived with a sampling stochastic dynamic programming model. The main objective of this paper is to present a probabilistic approach and forecast the inflows to Jiroft dam reservoir. In this regards, using ESP approach as well as Artificial Neural Networks (ANNs) the 1- to 12- month ahead probabilistic scenarios of Halil river were forecasted.

Nowadays, in water resources management, climate change is one of the main challenges. Changes in the water cycle are one of the most important of ground responses to warming it (IPCC 2014). Changes of precipitation and temperature caused by climate change, will damage to the products of garden and agricultural. Therefore, in order to increase the food security in future periods, it is necessary to evaluate the climate change impacts on the agricultural of regions and provide adaptation strategies its. So Regarding the importance of climate change, the purpose of this study is simulating the performance of the agricultural sector Hashtgerd Plain under climate change impacts in the future period (2020-2049).

Moisture flow through unsaturated zone is vital in agricultural engineering, soil science, groundwater hydrology, and environmental engineering. Moisture flow through unsaturated zone is complex due to the dependencies of flow and storage properties on the pressure head and is commonly analyzed by solving Richards’ equation. Solution of Richards’ equation requires the knowledge of soil hydraulic conductivity and water content versus pressure head functions referred to herein as the soil hydraulic properties. Since these functions are highly nonlinear, direct laboratory and field measurements are tedious, time consuming, and involve considerable uncertainty (Hari Prasad et al., 2010). An alternative to the direct determination is to employ the parameter estimation methods using inverse procedure for the determination of hydraulic properties. Indirect methods are divided into several categories, including methods based on pedotransfer functions, semi-physical, and inverse methods (Abbasi, 2007). Determination of hydraulic properties by inversion of in situ measured moisture contents, pressure heads and cumulative infiltration have become an alternative to direct measurements due to decrease in the computational costs and development of efficient optimization algorithms. Inverse solutions based on the Richards’ equation are now increasingly used for estimating the unsaturated soil hydraulic properties. The HYDRUS-1D model is one of the advanced models have been widely used to simulate one-dimensional water movement in soil. Examples of numerical studies in which infiltration data were used to inversely estimate the near-saturated soil hydraulic properties using HYDRUS model are by Simunek and van Genuchten (1996) and Rashid et al (2015). Water quality can impact on soil hydraulic conductivity changes. The effect of salinity on the hydraulic conductivity of soil has been studied by many researchers, including Moutier et al. (1998) et al. and Levy (2005). The researchers reported that increasing the salinity has increased the hydraulic conductivity of the soil. The purpose of this research was to evaluate saline water effect on unsaturated hydraulic properties and estimate these properties inversely using infiltration data.

Non-saline water resources are scarce, especially in arid and semi-arid regions. Therefore, the consumption of saline water is inevitable in agricultural usage. Iran has large saline water sources that have different levels of salinity. The use of these resources requires special management practices for the reduction of their negative environmental impacts. The usage of saline drainage waters, generated by irrigated agriculture, seems inevitable for plants irrigation. Salinity stress reduces the osmotic potential, as well as all major processes of plant including growth, photosynthesis, protein synthesis, and lipid and energy metabolism. Of course, the response of plants and tolerance of different species of plants are different to salinity. The rapid reduction of leaf area and number of leaves, decreasing biomass (dry matter) of the shoot and root, as well as reducing the plant height and active root level in the soil are among the plant responses to salinity stress. Salinity induced changes in photosynthesis, stomatal behavior, chlorophyll content and accumulation of metabolites at growth various stages of ber (Hooda et al, 1990; Ramoliya and Pandey, 2007). Investigating the applicability of agricultural lands drainage in irrigation of juvenile ber plantation and determining the production function of water salinity-shoot dry matter of juvenile ber were overall objectives of this research.

Each year rivers transport a lot of sediments, especially for flood times, to dams’ reservoirs and the main cause for this transportation is density current phenomenon. This phenomenon forms when a liquid with a density of ( ) flows in another liquid with density of ( . This density deference could be due to the temperature, or dissolve solids, or suspended solids deference or a combination of them (Graf and Altinakar, 1998). Vargavand (2013) made a density current using the solution of water and salt and investigated the effect of a bed with cylindrical and conical roughness on water entrainment coefficient. His results showed that the water entrainment coefficient not only affected by Richardson number but the height of bed roughness is also an important parameter. Daryaee (2014) investigated the water entrainment coefficients for four bed slopes, two sediment concentrations and four different bed roughness height in a sedimentary density current. The results of this research showed that by increasing roughness height velocity decreases and this increases Richardson number and a result water entrainment coefficient decreases. However, roughness blocks cause for more turbulent flow which extended up to interface of density current and ambient water and this phenomenon makes more water entrainment. The aim of this research is to investigate the effect of bed roughness, bed slope, and hydraulic parameters of density current such as flow rate and concentration on water entrainment of a salty density current.

Regime and hydraulic geometry are two of the most important proposed models over the past century in the related disciplines of river engineering and fluvial geomorphology. Therefore, the hydraulic geometry is of prime importance in planning, design, and management of river engineering and training works (Huang, 1996). The first systematic analysis was conducted on canal systems in India by Kennedy (1895) who exhibited a relation between velocity and depth. Downstream hydraulic geometry relationships describe the shape of bank-full alluvial channels in terms of bank-full width, average flow depth, average flow velocity and channel bed slope. Although some concepts of hydraulic geometry were proposed toward the end of the nineteenth century, the real impetus toward formulating a theory of hydraulic geometry was provided by the work of Leopold and Maddock (1953). Leopold and Maddock (1953) adapted the ideas from regime relations for canals to the description of natural stream channels. Generally, there are two experimental and analytical methods to obtain the hydraulic geometry relations in order to determine the stable geometric dimensions of the rivers. Different researchers have studied hydraulic geometry relations for straight rivers without considering the effect of the secondary flow. The main focus of this study is to analytically derive the hydraulic geometry equations considering the concept of secondary flow in meandering channels.

Since the importance of water in the durability and survival of life is clear to everyone, water issue has always been the focus of researchers and experts. Iran, having its own geographical and climatic location, has a small share of rainfall. Therefore, having an average annual rainfall of about 240 millimeters, one-third of the global average (860 millimeters), it is part of the dry and semi-arid climate (Alizadeh, 1997). Due to the lack of statistics, complexity of hydrological ecosystems and the impossibility of full recognition of the conditions in many catchment areas of the country, the use of methods that measure the amount of runoff from rainfall in non-statistical basins or those with incomplete statistics are of prime importance. One of these methods is the use of the capabilities of hydrological models in the simulation of hydrological processes which is one of the initial stages of water resources management and planning, and also the study of the hydrological effects of land use change and the way of exploitation of natural resources in a basin, where it is possible to simulate the hydrological processes, such as runoff, in the basins with complete statistics with the lowest cost and minimum time, and then use the information to estimate runoff in similar basins with no statistical data or incomplete statistics (Namdorost, 2002). LARS-WG5 is one of the generators of meteorological accidental data that is used to generate daily rainfall data, daily irradiance and maximum and minimum daily temperatures in a station under present and future climate conditions (Semenov and .Brooks., 1998). Zarghami et al (2001) reported a 2.3 degree increase in temperature and a 3 percent reduction in rainfall over the years 2020-2090 for East Azarbaijan province with the LRS-WG Exponential Meteorological Scale under the A1B, A2 and B1 scenarios using HADCM3 output.

Evapotranspiration is one of the most important factors in hydrological cycle. Potential evapotranspiration is used to design in irrigation and drainage networks and hydrological studies (Davis & Dukes, 2010). The conducted studies in different regions of the world have shown that the FAO-Penman-Monteith model can be presented as the most accurate method under various climatic conditions (Irmak et al, 2003, ASCE-EWRI, 2005, Jabloun & Sahli, 2008, Martinez & Thepadia, 2010 and Azhar & Perera, 2011). The calibration of the mentioned equation using lysimetric data in a wide range of climatic conditions and its applicability without the requirement for local calibration in different climatic conditions are the benefits of the FAO-Penman-Monteith equation (Landeras et al, 2008). On the other hand, the Valiantzas model is one of the newest methods for estimating ETo. Advantages of using the Valiantzas equations in the estimation of reference evapotranspiration include simple application for spatial calibration, easy application for temporal distribution of reference evapotranspiration values, easy use for routine hydrological applications and simplicity of equations for other hydrological applications (a, b, c, Valiantzas, 2013). The purpose of this study was to evaluate and compare the accuracy of five different Valiantzas models for estimating reference evapotranspiration at the studied stations located in the northwest of Iran (Urmia Lake basin) including Urmia, Salmas, Mahabad, Takab, Tabriz, Sarab and Maragheh and providing the best version of the Valiantzas as the results of which are the highest concurrence with the FAO-Penman-Monteith method.

Limited water and soil resources and growing population have led countries around the world towards raising agricultural production per unit area and optimal utilization of these resources. Due to the population growth and rising living standards, the demand for food has increased. In this regard, identification and knowledge of the parameters that somehow affect food production is essential. Using new techniques for selecting appropriate land irrigation methods can enhance water use efficiency in farm lands. Selecting a proper irrigation method in irrigated agriculture in order to achieve a high efficiency and maximum water use. Nowadays Fuzzy systems are one of the most efficient methods in the field of forecasting and modeling (Akbarzadeh et al, 2009). Fuzzy system is able to use human language and human experiences and experts and connoisseurs (Karatalopoulos, 2000). Sys, Vanranst and Debaveye (1991) proposed parametric evaluation system to select irrigation methods based on physical and chemical properties of soil. Using fuzzy logic capabilities which stem from the ability of continuous membership function of input variables and by combination of parameters affecting irrigation methods evaluation in parametric system with fuzzy logic membership functions, it is possible to assess farm lands for choosing the right irrigation method more accurately. Therefore, this study aims to utilize the functionalities of fuzzy logic method to evaluate land suitability of the area studied based on parametric system for two drip and sprinkler irrigation methods.

Simulation of lateral distributions of velocity and suspended sediment concentration in river bends is of great significance, and has many applications for river engineering projects. Due to secondary flow development, flow structure in river bends has 3-dimensional nature. As shown in Fig. 1, the secondary flow, coupled with the longitudinal primary movement, causes a helical flow that forms in the river bend (Perkins, 1970). In this case, 1-dimensional mathematical models (e.g. HEC-RAS, MIKE-11 and ISIS) are generally not satisfactory and 2 or 3-dimensional mathematical models should be used instead. However, the large amount of computational time needed to simulate flow field in rivers by 3D or 2D mathematical models, justifies the use of quasi 2D modes. Among the numerous quasi 2D models, the Shiono and Knight model has attracted great attention of river engineers. This mathematical model is based on the depth averaged integration of Navier-Stocks equations. Due to suitable form of in this study, at first with field measurement of lateral distributions of velocity and suspended sediment concentration in three bends located at the Karoun river (namely Maliheh, Jangieh and Khabineh), the Shiono and Knight quasi-two dimensional model (1991) has been calibrated. Using the lateral velocity profiles obtained by this mathematical model, sediment transport capacities were computed. The results showed that in all three river bends, among the empirical sediment equations selected for this study, the sediment transport equation of Yang has very well agreement with the measured lateral suspended sediment concentration, in comparison to the Ackers-White and Engelund-Hansen equations.

Iran is located in arid and semi-arid areas of the world and the major factor in this region is water shortage. The shortage of water in the country has limited food production and agriculture activities. More than 94 percent of the water resource of this country is used in agriculture sector, but the overall efficiency of irrigation in the country is between 33 and 37 percent. Therefore, despite the water crisis in the country and regarding the low turnover in irrigation, efficient use and management of water in agriculture sector is unavoidable. One program that has been implemented by Jihad of agriculture ministry in villages and cities to increase the efficiency of irrigation in agriculture sector is optimal water consumption plan In this plan, water demand for producing each yield unit is taught to beneficiaries to avoid excessive water in irrigation. This study aimed to suggest strategies for the development of this plan in the country. These strategies presented by SWOT method and prioritized by QSPM matrix. Nuga and Asimiea in 2015 used this technic to analyze agriculture sector in Niger. Based on results, the usage of international budget for developing of environmental educations in villages introduced as the most significant strategy, having the highest score.

The study area (Lavar plain) is part of the Kol River catchment and is located about 60km in North of Bandar-Abbas, in Hormozgan province, south of Iran. The study area lies between longitude of 56º 51´6´´– 56º 1´ and Latitude of 27º 32´22´´ - 27º 36´. The area’s elevation ranges from 240 m to 2900 m from sea level (Fig.1). The climatic condition of this study area is influenced by medium elevation (240 m) above the sea level. As it is normally hot, temperatures are not below zero. Additionally, the study area is affected by the air mass systems mentioned above, whereas the first and third portions are more influential on precipitation. The main rainfall is related to cyclones that pass from western to eastern direction. The majority of cyclonic activity originates from the Persian Gulf, normally from January to March. Laver Dam is located in the eastern part of the plain. The dam is constructed on the river that is collecting runoff from the two sub-basins of the Sarzeh - Rezvan and Gnou in the reservoir of the dam. The groundwater aquifer is an unconfined aquifer with an area of 23.5 square kilometers and surrounded by sandstone formations and conglomerate. The study area is located in the Zagroos folded zone. In the study area, the oldest formations are of Paleozoic age. Another characteristic of the Zagroos zone are diapers. Diapers rise up from the deepest part of sedimentary rocks, and after cutting through the upper layers, they may appear at the surface, which seriously affect groundwater quality and land use.

A hydraulic jump is a sudden transition from a supercritical to subcritical flow with a broad range of turbulence Scales. The fluctuating nature of the flow such as oscillations of jump toe position and production of large eddies are visible in pseudo-periodic manners. Energy dissipation of hydraulic jump occurs with Low-frequency large scale pressure fluctuations which can cause damage and erosion and endanger the security of the structures. In the present study, the effects of discontinuous roughness elements of lozenge shape on the fluctuations of pressure in hydraulic jump have been investigated.

Water intake from the river is done using several methods. Each method has its own features and limitations. In steep mountain rivers with irregular bed, high values of sediment transport and flash floods may prevent the application of gated dams; therefore, the bottom intakes are often used. In this method, in some part of the river width and length, a trench is created with a proper cross section and water is flowed through this trench into the diversion channel. In order to prevent the coarse particles to enter, top of the trench is covered with bottom rack bars. Corrosion of the bars, clogging, and maintenance are the common problems of bottom racks, which make them unusable in long term. To solve these problems, a new system of bottom intake with porous media is introduced. In this method, after trenching in the river bed, materials with appropriate aggregation are ‎dumped in the trench and water intakes from the river through a diversion channel. ‎ This means that a portion of flow into the porous media; then move to the diversion channel. Another portion of the water passes over the bottom intake and finally drive to the river. Usage of the porous media has, however, many limitations; but it has some advantages, such as, no suspended solids in the water, respect for the environmental problems, no change in natural morphology of the river, withstanding in different weather conditions, and dealing with the problem of freezing, and corrosion, easy to construct and applicability, affordability and availability of materials. Despite a long history of research in thre field of bottom rack intakes, few studies about these structures with porous media have been previously done. In previous experiments, in order to separate the diverted flow from the non-passed flow, a bottom intake with porous media with a diversion channel parallel to the main channel was used, so that the diverted flow was unidirectional to the main channel. But, in practice, diversion channel in the bottom intakes is usually performed perpendicular to the main channel. Therefore, it affects the hydraulic parameters and diverted discharge. Besides, in previous experiments, by considering the constant height and length, the effect of these two factors has not been investigated for the intake. Therefore, in the present study, in order to precisely investigate the hydraulic behavior of the bottom rack intakes, in addition to the implementation of a channel perpendicular to the main channel as a diversion channel, various factors such as the length and height of the intake, the effects of uniformity of particles and different slopes of intake have been experimentally investigated. The results of experiments on laboratory models in this study may reveal some of the unknown points in application of this method and it provides the possibility of design and operation of this structure in the natural environment.

Hydraulic jumps are the most important type of rapidly variable flow that occur in from the supercritical state to the subcritical state with the sudden increase of the water free surface in a relatively short path, and usually has a high kinetic energy dissipation. The presence of a barrier against the flow will result in the separation of the inlet jet and more energy depletion resulting in increased shear stress and increased drag force. As a result, the jump length and conjugate depth decreases. These obstacles must be structurally sound because they are directly in front of the jet. If the flow rate exceeds 17m/s, it will cause a cavitation phenomenon (peterka, 1985). Another factor that can reduce the dimensions of a hydraulic jump is the roughness of the floor. Rajaratnam(1968) conducted the first systematic studies of jumping on a rough bed. The results of Rajaratnam were confirmed by Hager(1992), and, with their study of acoarsebed, Ead and Rajaratnam(2002) showed that the jump length on the rough bed is almost three times the conjugate depth (Lj/Y2=3). Shows that the rippling bed has halved the length of the jump to the length of the USBR-I pond. Studies on roughened bed reveal that the use of rough substrates requires more experiments to determine the proper shape of roughness. Hence, in this study, roughnesses in cubic, triangular and cubic and triangular combinations with zigzag arrangement have been investigated on the hydraulic jump specification in the rang of 5.13 to 9.75 froud numbers.

A Stilling basin with divergent section has better performance and lower constructional costs than the classic basin. It can easily adapt itself to the upstream and downstream conditions in terms of depths and cross sections (Omid et al., 2007). Khalifa and McCorquodale (1979) studied radial hydraulic jumps in a gradually expanding channel of rectangular cross section and developed a theoretical equation assuming a second degree polynomial for the surface profile. Omid et al. (2007) studied the hydraulic jump formed in a gradually expanding stilling basin of trapezoidal cross section. They also investigated the hydraulic jumps for three different basin side slopes. Their experimental results indicated that the divergence of the basin for a given side slope causes reductions in the sequent depth and jump length, and an increase of the energy loss in jump relative to those observed in rectangular cross sections. Sahebi (2013) simulated a divergent hydraulic jump in rectangular basins using standard and RNG turbulence models. The outputs of the numerical model showed that the standard turbulence model evaluated the free surface of flow, jump length and maximum velocity in defined sections better than RNG turbulence model. In this study, for seven Froude numbers in the range of 3.2-9.1, three models of the divergent basins were numerically simulated at three dimensional conditions with various geometries of divergence angle and wall type. The k-ε RNG and RSM models were used for turbulence analysis and volume of fluid (VOF) model was used for simulating of free surface profile in the Fluent model. Also, vertical distributions of turbulence intensity, Reynolds stresses and turbulent kinetic energy were investigated using the RSM model in various sections of the hydraulic jumps.

Irrigated agriculture is the main user of the available water resources. About 70% of the total water withdrawals and 60-80% of total consumptive water use are consumed in irrigation (Sepaskhah and Ahmadi, 2010). Due to changes in climatic parameters and reduction of available water resources, The application of water saving strategies such as deficit irrigation with choosing suitable cultivation system compatible with ecological characteristics of the area such as intercropping, can reduced water use consumption. Many researchers have studied the effects of these methods on some components of yield and water use efficiency (Anderian, 2004; Caviglia et al, 2004; Filho, 2000; Tahir et al, 2003). In recent years, the concept of alternate partial root-zone drying irrigation has been raised and attracted considerable interest. Partial root-zone drying technique (PRD) is a modified form of deficit irrigation which involves irrigation only one part of the root zone in each irrigation event, leaving another part to dry to certain soil water content before rewetting by shifting irrigation to the dry side (Sepaskhah and Ahmadi, 2010) that this technique has been less investigated in intercropping system. The objective of this study was to investigate the effects of regulated deficit irrigation (DI) and partial root-zone drying (PRD) on yield and some components of intercropping Sorghum- Red bean.

'Transition' is a short hydraulic structure used to change the cross-sectional shape or flow shape. Transitions are commonly used both in the open-channels and natural waterways. The task of a transition is to connect a narrow channel at the upstream to a wider downstream channel or vice-versa. This, creates a disturbance region of turbulent flow causing energy losses. In general, the structure of a transition prevents the formation of wave and other turbulencies. In this case, the energy loss, due to the change in the amount of the momentum, will be minimized.

In places where the flow velocity is high, due to the unevenness of the spillway bed , the streamlines are separated from the bed, and at the downstream area, the pressure drop occurs and ultimately leads to the destruction of the spillway bed (Raesi, 2011). Jonson (1963) showed that, if the vacuum is formed inside the vortex core, the initial value of the vacuum should be less than or equal to one. Ohern and Katz (1986) have shown in their research that the beginning of the initial vacuum is in the three-dimensional structure inside the nucleus and not in the nuclei of the circuits. Savage and Johnson (2006) have found that a numerical model is useful for determining the flow rate and flow pressure by comparing the numerical and physical model of the flow over the Ojee spillway. Zhang, Wu and Dong (2010), with the help of the model made in the Hydraulic Laboratory of the University of Zhijiang, have studied the effect of air mixture in flow on the surface pressure and vacuum, and showed to have a positive effect on air concentration. ShafaiBajestan and NasrEsfahani (2014) investigated the cavitation phenomenon at the stilling basin with a rough bed and an abrupt drop. In this study, factors affecting the index of cavitation like velocity, pressure and the amount of air into the stream in five states of without aeration, with ramps on the bed, with ramps on the bed and wall duct, with a ramp in the walls, and also with a ramp on the bedand the wall was examined.

Accurate prediction of the river flow is an important element in the management of surface water resources, dam reservoir operation, flood control and drought. Selecting appropriate inputs for intelligent models is vital to increase the accuracy and efficiency of the models. Since river flow prediction is of great importance in water resources, researchers have been exploring different approaches over the past several decades. Various methods have been devised to predict the flow of the river over the past years. In general, we can classify conceptual models and data-driven methods. Over the past four decades, time series models have been widely used in river flow prediction (Dawson et al., 2008). Intelligent systems are used to predict nonlinear phenomena. The Bayesian Network and the Artificial Neural Network are among these methods. Ahmadi et al. (2014) studied the comparison of performance of support vector machine and network methods in forecasting daily flow of the Barandozachay River. The results showed that, both methods are close to each other and are suitable for river flow simulation. But in mid-range forecasting and the minimum backup car model, it's much better than the business network model. Shannon entropy theory was first developed by Shannon and then widely used in various scientific issues. The purpose of this study is to use the Shannon Entropy Theory to find the best combination of input variables for artificial neural network and Bayesian network models to predict the flow. Therefore, for this purpose, the Sufi River of the studied area was selected.

Drought prediction in water resources systems plays an important role in reducing drought damage. In recent decades, Traditional methods including: fitting and mathematical models have been widely used to predict droughts. The combination of wavelet theory and neural networks has led to the expansion of the wavelet-neural networks. The application of the wavelet as training function in the neural network has recently been identified as a substitute method in neural networks. In these models, the position and scale coefficients of the wavelets are optimized in addition to the weights (Thuillard, 2000). Considering the importance of short-term drought prediction in water resources engineering and the nonlinear characteristics of the SPI series of three months, the purpose of this study is to present an Artificial Wavelet Neural Networks integrated model for predicting short-term drought at Bidestan station in Qazvin plain. In this research, Multi-Layer Perceptron (MLP), Radial Base Function (RBF), ARIMA time series, as well as Artificial Wavelet Neural Networks integrated model and Multi-layer Perceptron (WA-MLP) and Radial Bonding Function (WA- RBF) were used, which is done by analyzing the time series investigated by the wavelet transformation and the entry of these sub-series into an artificial neural network. According to previous researches on drought prediction, short-term drought prediction (with the definition of a three-month standard rainfall index) using the combined model of Wavelet-Neural Network and comparing its results with artificial neural network and ARIMA time series models has not been compared. In this paper, five short-term drought prediction models have been compared and a better performance model has been introduced.

In reservoir of dams, especially near the dam body, the cohesive fine sediments are deposited mainly. The mechanical behavior of these sediments is largely controlled by the interparticle attraction caused by electrostatic and physiochemical forces. these properties cause the stickiness and accumulation of clay particles and formation of dense masses called flocs, which is sometimes referred to as flocculation. flocculation is influenced by several factors including salinity, flow regime, sediment concentration and organic matter. Flocculation is the most important factor that makes the settling, fall velocity and transfer of cohesive sediment considerably more complex and dynamic than non-cohesive sediments. In order to determine the relations governing cohesive sediments, the physical characteristics and behavior of these sediments should be identified. The terminal settling velocity of sedimentary particles in liquids, called particle fall velocity, is one of the most important properties in determining the physical properties of sediments caused transfer, deposition and consolidation. The fall velocity of cohesive sediments is influenced by many factors, including salinity, initial particle size, turbulence, temperature of water, and suspended sediment concentration. McLaughlin (1959) provided a method for measuring the fall velocity of particle (ω) in stillwater, using a settling cylinder with 10 cm diameter and less than 1 meter height and established a differential formula based on its research as follows: d(wC)/dz+dC/dt=0 (1) Fathi Moghadam et al (2011) studied the settling properties of the cohesive sediments in the Dez Dam reservoir. They concluded that particles for all concentrated samples and in all depths reached to their maximum fall velocity approximately at the same time (15 minutes after starting the test). The lower concentration samples appeared to have higher maximum fall velocities than the higher concentration samples, but for a shorter duration.

Derived Information from the predicted waves will be the basis for engineering design and plays an important role in the construction, maintenance and management of coastal and offshore construction projects. The wind-induced-waves due to having high energy and frequency are of great importance in the sea. In this research, the adaptive network based fuzzy inference system was selected to predict the waves’ characteristics.. Study About prediction of wave Characteristics is carried out by several researchers. Zarghani et al (2006) studied the characteristics of wind-induced waves at the coast of Khark island They used the SPM model to conduct the survey. The results obtained from the model showed that the highest wave was 3.7 m with rotation period of 6.8 seconds. Taleghani and Amirteimori (2008) used the field data of the Caspian Sea waves measured by a waveguide buoy in an artificial neural network. Finally, the comparison of real data measured by the measurement systems with the results of the neural network is a good match that indicates the accuracy and speed of the method used in the short term. Kamranzad and Etemad Shahidi (2011) studied the prediction of wind-induced waves in Assaluyeh using the SWAN numerical model. The validation results of the model showed that the results of calibration model have a good accuracy. The calculated error indices in validation periods also showed the acceptable accuracy of SWAN modeling. Therefore, the constructed model had the ability to predict wave height and period of time in Assalouyeh. In order to do present research, the Adaptive Nero-Fuzzy Inference System as one of the soft computing methods is used. The study area chosen Bushehr and forecasts for the period December 2008 to 2010 is considered. The results showed that, in prediction height of wave induced by wind, accuracy of the Adaptive Nero-Fuzzy Inference System and decision tree are same and are higher than the empirical methods. The comparison results of prediction from empirical methods showed that among the experimental methods, SMB method with high correlation coefficient and less error percent than the other experimental methods has higher accuracy in estimating height of waves in addition the SPM method is not suitable method for determining the height of waves and under estimated the real values.

Water erosion causes serious damage to all natural ecosystems, including the soil and nutrients loss (Collman et al., 2010). Nutrients loss and soil fertility reduction are the most important effects of soil erosion, which increase the fertility of soils in downward of the basin and cause contamination of surface and underground water (Telles et al., 2013). Soil loss is a serious problem in developing countries and has been a source of concern (Wolancho, 2012). Phosphorus and potassium are important elements in agricultural products. Each of the mentioned elements has especial behavior in transferring by runoff. Potassium is very mobile in comparison with phosphorus, so it is easily displaced by water from the runoff process. Despite numerous studies done in the world regarding the loss of elements in runoff and sediment, there is no accurate information in this regard in Iran. In Lorestan Province, due to the lack of attention to land suitability in land uses, basins are severely subject to erosion and soil degradation. Therefore, the present study was conducted to investigate the effects of slope and type of land use on the loss of potassium and phosphorus in runoff in Kakasharaf Basin in Lorestan province.

Watermelon is one of the most important profitable vegetables in Khuzestan. A mild water stress helps watermelon to develop the root system. Water stress has a negative effect on the yield of watermelon but it increases the quality of the fruit. Watermelon is usually planted in mid-June and is irrigated in a furrow irrigation which, generally, has low application efficiency. The high amount of water consumption, especially in the early stages of growth, requires considering the drip irrigation method. Recently, using drip (tape) irrigation has become more common in Khuzestan. However, there is not enough information regarding the impact of pressurized irrigation systems on the performance of watermelon varieties. Therefore, the current research was conducted with the aim of evaluating tape irrigation levels on watermelon varieties in Northern Khouzestan.

Introduction Water allocation in arid and semi-arid regions is considered a human challenge all around the world. The need for optimum utilization of water resources, especially in agricultural use, is very important. Agriculture, which uses the greatest percentage of most water resources, has also penetrated in human life and culture. The aim of this study is to provide an approach to allocate and optimize water use in Dez basin using WEAP model. Methodology The date regarding the users of water resources in Dez basin including the agricultural, domestic and industrial water demands, the precipitation, and the flow of rivers were collected from 2009 to 2014. All data were averaged monthly. The conceptual model was defined in WEAP. In term of model calibration, 60 percent of runoff data were used. The other 30 percent of remaining data were employed for the validation part. The optimum utilization policy of water resources in various scenarios were defined in WEAP. The scenarios were tested based on cropping pattern changes, reducing agricultural area, and the changes in irrigated and rain-fed ratio. All scenarios were compared by the reference scenario. In this scenario, the lowest percentage of need was related to the Western Dose. In this scenario, the course was 100 percent selected for drinking and industrial purposes in cities (Dezful, Andimeshk, Shoosh, Safi Abad, Dezab, Mardrood, Hor, Hamza and Saleh Shahr) and the entire villages of the region and some small industries due to the priority of providing higher, water use efficiency. On the other hand, due to the water withdrawal, regardless of the needs of the downstream and the transition to Karkheh, the percentage of providing low consumption needs as well as the percentage of the environmental need was not satisfactory. In order to improve the status of the reference scenario and the basin, two scenarios were defined. Considering that the agricultural sector is the largest water consumer in the region, it would be possible to significantly balance the supply-demand balance between water supply and demand by reducing the consumption in this sector. The scenarios were designed to reduce water consumption in agriculture and increase its economic efficiency in the basin. In all scenarios, the objective function was to optimize the benefit by cost ratio. In the scenarios implemented, the confidence level of other water uses, including the needs of the plain, downstream, environmental requirements, and energy requirements, was calculated to be 100%. In the second scenario, the water consumption of each product was studied in each plain. Regarding the diversity of products, in each plain, the products with high crop yields were considered and given the amount of water consumed by each plant. Moreover, the performance and the guaranteed price of purchasing those high-value products were identified and replaced with low-cost products. Finally, in the third scenario, by varying the percentage of irrigated and rain-fed products, the study of the amount of water saved versus the decline in the production of products was studied. Then, by evaluating the price of water versus crop products, the efficiency of this scenario was examined. Also, for each plain, the optimal percentage of irrigated and rain-fed area was determined. The optimal water and dry crop percentage was estimated based on the performance of these products and the amount of water consumed.

Using some additive materials to gypsum soil can increase its compressive strength and erosion and make it fit for civil projects in irrigation networks. In this study, (Journal No. 268., 2003) five levels of cement (5, 8, 10, 12 and 15 % to dry soil) and three levels of micro silica (0, 5 and 10 % cement) were added to the local soil. The processing of soil samples were conducted in two temperature (27 and 400C) and their compressive strength was studied and analyzed via SAS statistical software. In the present research, the best combination, with the minimum addition and a high compressive strength, was reached by adding 10% cement and 10% micro silica to the soil. In order to evaluate the sample’s erosion potential, it was exposed to water jet plane in four angles (Ө = 0,30,60, 90), five speeds (V = 2, 4, 6, 8 and 8.64 m/s) and three times (T =4,8 and 12 hr) and the highest weight loss erosion (dw) was observed between the speed of 4 to 8 m/s and the time of 8 hours later in a horizontal state (0 Ө =). .

When water resources are limited, the type of plant, growth stage and soil type should be considered for optimal water consumption. Also, it is necessary to calculate the reliable values ​​of soil moisture content, moisture stress and yield function in order to apply deficit irrigation. Management of water consumption in agricultural sector, regardless of water, soil and plant relationships, requires time and cost. Therefore, models of water, soil and plant relationships have been developed due to the limitations of these experiments regarding farm conditions, the short duration of the experiment and the limited number of scenarios examined in the experiment. Optimal irrigation planning is one of the main factors in promoting water productivity and yield. Models such as the AquaCrop which simulate the effects of water levels on yield are useful tools for on-farm water use optimization. Alizadeh et al. (2010), with irrigation on wheat in Karaj on five treatments with 100, 80, 60, 40 and 20% water requirement as well as a single-irrigation treatment and evaluation of the Aquacrop model for these treatments, concluded that the model was efficient for predicting the amount of seed yield, plant evapotranspiration and water use for 7-day irrigation intervals. The model was, however, less efficient for 14-day irrigation intervals. Babazadeh and Saraei Tabrizi (2012) in their research on soybean plant in Karaj showed that this model had a good performance in simulating product yield, evapotranspiration and water productivity, and that it could simulate the amount of evapotranspiration with an error of less than 4%. Although some studies have been conducted to evaluate the performance of the model in simulating the effects of irrigation on different products since the development of Version 4 of the Aquacrop model, there have been no comprehensive studies on how the model reacts to water stress in different growth stages. Therefore, the main objective of this study was to calibrate and evaluate the Aquacrop model in simulating the response of wheat under deficit irrigation conditions in different periods of plant growth in Shahrekord climate by comparing the results of field experiments to verify its accuracy in predicting different parameters such as grain yield and total dry matter in wheat.

Groundwater resources are known as one of the most important water resources. Proper knowledge and exploitation of groundwater, particularly in arid and semi-arid regions, plays an important role in sustainable development in different fields such as agricultural, social, and economic activities. Many models have been used in order to predict groundwater level including empirical time series models and physical models (Bierkens, 1998). It is true that these models have been widely used, but when the dynamic behavior of a hydrological system is changed during the time, the mentioned models may not be able to predict water resource parameters, therefore making them unsuitable (Nayak et al. 2006). On the other hand, physical models need a great deal data to simulate groundwater fluctuations and, since the relations among effective parameters may be nonlinear, the mentioned models are not practical enough to show the existing relations.

Insertion of different water structures such as bridge piers in the flow path contracts the flow cross section and causes backwater at upstream sections. The velocity and turbulence of flow increases around these structures and bed scouring will occur. To discover the effect of different structures in the vicinity of channel junctions on flow and sediment patterns, precise studies should be conducted. The effects of bridge pier on flow and sediment patterns in stright and curve open channels have been investigated (Salaheldin et al., 2004, Tabib zadeh et al., 2005). However, its effect on flow and sediment patterns at open channel confluences has rarely been studied.

Forage sorghum is one of the tolerant salinity plants that can provide a good source of forage under irrigated conditions with saline water. Considering the quality of the products, their value is estimated with regard to their quality. Therefore, similar to many crops, the quality of forage plants should be considered. The quality of forage can be a function of forage consumption and its digestibility(Paterson et al., 1994). Forage plants in livestock trapping as a result of livestock production are undeniable in the supply of human needs. Unfortunately, in Iran, less attention is paid to the production and management of forage compared to other crops. As a result, lack of attention to the quantitative and qualitative increase of forage has led to a shortage of meat and dairy products and a decrease in their quality. Therefore, paying attention to the cultivation of forage plants with a scientific method in a country that is faced with the excessive growth of population and the shortage of rich meadows is very important (Noroozi et al., 2015). Sorghum is one of the important forage crops that is widely cultivated as summer forage in most of the dry and semi-arid countries of the world. Forage sorghum is used as green, dry, silage, or even for direct grazing of livestock (Rezvani moghaddam and Nasir mahallati, 2004). In thecurrent research, the effect of drought stress on sorghum was investigated. The results showed that the yield components including the number of seeds per plant and weight of 100 seeds decreased compared to the control (Innes and Black, 2001). Therefore, in this study, the effect of different levels of salinity and irrigation water and harvest on the yield of forage sorghum was investigated in order to use the results for proper planning to increase agricultural production in specific conditions, i.e., salinity and water restriction.

Introduction flood control is one of the important requirements in development projects of major water resources. In this regard, the main purpose is to reduce or eliminate the economic, social and environmental damages that are caused by floods. On the other hand, many irrigation and drainage networks are in the vicinity of the rivers and, therefore, the occurrence of floods can cause irreparable damage to the land and network structure. Embankment failure due to water overtopping during floods is a common phenomenon which brings great financial losses, human casualties and environmental damages. Therefore, this research was aimed at investigating the mechanism as well as the effective variables on embankment failures.

Scour around piers and abutments leads to a lot of bridge failures. Scouring around the bridge piers and abutments is one of the most important factors in bridge failure which happens over time and increases during floods, probably causing general damage to the bridge. Accordingly, the accurate estimation of scouring around the bridge piers and abutments can help engineers to take steps to deal with bridge destructions. Recently, data-driven models have been used widely to estimate the scour depth around bridge piers and abutments. Najafzadeh, Barani and Hessami-Kermani (2015) used a set of data-driven models such as the gravitational search algorithm and the particle swarm optimization algorithm to estimate the scour around bridge abutments. Sediment particles size, geometric characteristics of bridge abutment and approach flow conditions were considered as effective parameters on scouring mechanism. The results of this research showed that data-driven models can estimate the scour depth with high accuracy. In the present study, M5 tree model has been used to predict maximum scour depth around bridge abutment. High accuracy, simplicity and understandability are considered the advantages of this algorithm. A huge amount of data from credible references have been used to build and validate the tree model.

draining the flood of enormous dams and transmitting the procedure to the downstream is one of the important issues regarding hydraulic structures. Plunge pools are the main structures to dissipate the high rate of energy. The amount of energy at an outlet jet depends on various parameters such as the dropping height, the thickness of the jet, and other environmental conditions. Local erosion in plunge pools with alluvial beds is a complex phenomenon and determining the geometric features of the scour hole is really difficult. The outlet flow mixes with the turbulence factor and hits the bed of the plunge pools with a semi-perpendicular condition. Therefore, the present study was conducted to determine the scour which was caused by inlet air along the middle water jet on the bottom of the plunge pools. Xu et al. (2004) tested the aeration effects on the scouring caused by the falling jet and obtained a small relationship between the percentage of air jet density and the relative scour depth. The results informed that aeration affects the shape of the scour hole and essentially reduces the scour depth. Manso et al. (2004) investigated the interaction of the geometric shape of the submerged pond with rocky bedding on the rate of diffusion of the falling jet. They tested various diameters of jets,5.5, 11 and 16.5 times the diameter of falling jet, on the smooth and rough beds to investigate the dynamic pressures with frequencies between 1 to 2 KHZ. Their findings showed that the geometric shape of the pond has a direct impact on the jet diffusion rate. Duarte et al. (2015) studied the effects of air inlet to jet on the dynamical pressure on the floor of the submerged pond. They increased the jet's velocity to 22 m/s. The final results showed that the air inlet to the jet led to a decline in the total pressure on the floor of the pond.

Limited water resources and energy, low yield utilization of irrigation networks, increasing population and a growing need for these vital resources reveal the necessity of proper planning for optimum use of water resources. The cropping pattern has a major role in the design of irrigation and drainage networks. Ziaei et al. (2015) compared energy productivity of different crops (wheat and barley) in Sistan and Baluchestan province in Iran. Results showed that the amount of energy productivity for wheat and barley fields were 0.056 and 0.066, respectively. Barley production was more efficient from various aspects of energy consumption rather than wheat in the studied region. Adhikary et al. (2015) prioritized the commonly grown crops based on rainwater use efficiency and their comparative performance during water stress condition in India. Results showed that vegetable crops have higher rainwater use efficiency than cereals and pulses. Among the cereals, maize and finger millet performed better in upland areas while they did better in paddies in low lands. Igwe et al. (2015) examined optimum cropping patterns for selected root and tuber crop based production and resource allocation of smallholder farmers in Abia State, Nigeria, using the linear programming approach. They reported that farmers’ purchasing power would be enhanced given optimal crop production activity combination and land resource allocation. Singh et al. (2001) and Garg and Dadhich (2014) also studied on optimal cropping pattern in Pakistan and China, respectively. The present study was performed to determine the prioritization of cultivating major agricultural crops (wheat, maize, alfalfa and barley) in sprinkler irrigation systems under both subsidized and non-subsidized conditions with respect to energy and water costs using numerical taxonomy method.

Drought refers to a period of time when water shortage occurs and, therefore, the environment and human life are disrupted. Of course, depending on the regional considerations and the objectives of any research, drought can have different definitions since the lack of water in different regions is defined differently. Drought forecasting is almost impossible and is usually a phenomenon that progresses slowly. As a result, well-timed detection in the early stages makes it possible to reduce the adverse effects on different parts of the environment, agriculture, water resources, etc. Drought characteristics such as duration and severity can be determined by drought indices. Scientists have proposed various indexes to assess this phenomenon. Drought index is a useful tool to assess drought characteristics. Effective Drought Index (EDI) is a new methodwhich is based on the cumulative daily precipitation and uses a weighting method.

The AquaCrop model improves farm management practices, including plant density, planting time, and chemical fertilizers. It also simulates crop yield, soil water content, soil salinity, and water productivity. One of the applications of this model is the assessment of rainfed production during the long term, the effect of low fertilization, the productivity of real water on the farm, and the analysis of future climate scenarios. The disadvantages of this model include the lack of calibration of the amount and time of fertilization and the lack of consideration of plant diseases and weeds (Raes et al., 2009). The AquaCrop model is suitable for simulating different water and nitrogen managements on yield (Khoshravesh et al., 2012). Ebrahimi, Rezaverdinejad and Majnooni Heris (2015) evaluated the AquaCrop model under different irrigation and nitrogen fertilizer managements for estimating maize grain yield and biomass in Shiraz. This model predicted the grain yield of maize with high precision and biomass obtained in all treatments was more than the estimated values. Alishiri, Paknejad and Aghayari (2014) in simulating sugarbeet growth under different irrigation regimes and nitrogen fertilizer concluded that the highest error in performance simulation was in the treatment that had the highest fertilizer stress. The purpose of this study was to calibrate and validate the AquaCrop model for estimating the crop grain yield (GY) and biomass (B) of Canola under different irrigation regimes and pure nitrogen fertilizer levels in loamy soils in Gazvin, Iran, for two years.

Selecting a model that simulate the runoff with high accuracy and less error, can be helpful in favorable management of water resources plans and increasing the performance of these plans. Also, increasing the accuracy of runoff simulation in the basins with no meteorological data, is of great significance in efficient management of water resources in these basins.

Due to the impact of various factors, selecting the best irrigation method for different conditions of the field has become a complex issue (Montazar and Behbahani, 2007). In this study, the best irrigation system selection among the sprinkler systems (including solid set, hand move, wheel move, traveling gun, center pivot, and linear move), trickle systems (including row crop drip, drip, and bubbler) and surface irrigation systems (including basin, border strip and furrow) was done using Charles Burt scoring method (Burt et al., 1999) for Famenin, Qahavand and Razan plains of Hamadan province. Scoring of the systems were performed based on some related properties such as the type of production, type of water source, climate, land, soil, social structure and, conditions of the studied regions. According to the results, the best choices and suitable irrigation methods among the mentioned systems based on their priority in the studied area were; solid set, drip tape and basin methods in sprinkle, trickle and surface irrigation systems respectively. Despite increasing the labor costs due to sprinkler’s displacement, the solid set method with moveable sprinklers due to less investment was selected as an appropriate and advisable system. If surface irrigation system is identified as the suitable choice for an area, the use of low pressure distribution networks and gated pipe systems can improve the irrigation efficiency and reduce the infiltration losses, which should be considered in projects.

Spur dikes are one of the coastal protection methods. Bandal- like is a local type of spur dikes that would be constructed to improve the water depth for navigation in alluvial rivers. This is a new type of spur dike that is a combination of permeable and impermeable spur dike. The goal of this study was to investigation the effect of Bandal-like spur dike submergence on bed topography. For this purpose, Bandal-like was tested with 3 submergence ratios of (1/16,1/65,2/15) and different hydraulic conditions (0.22,0.235,0.26 and 0.29 Froud number) in mild 90 degree bend. The result show that by increasing of the submergence ratio, scouring around Bandal-like increase too. Also, the results showed that by increasing of the Froude number and densiometric Froude number, the maximum scour depth increases too The investigation of the maximum scour showed that the location of scouring does not match the shear stress pattern in mild bends.

Developing of techniques for regional flood frequency estimation in ungauged sites is one of the foremost goals of contemporary hydrology. The flood frequency evaluation for ungauged catchments is usually approached by deriving suitable statistical relationships (models) between flood statistics and basins characteristics. Already, several equations have been presented to estimate the flood frequency in different areas such as Karkheh basin. However, due to the complexity of this phenomenon, the relationships have not been capable to simulate the flood frequency with desired accuracy. Accordingly, in this study, in addition to the regression method has been used in the previous studies, the ANN and ANFIS models are applied. In fact, these are a type of black box models without any knowledge of processes within the system, in which inputs are converted into outputs (or output). This situation indicates that this type of new models is actually similar to the regression relations, however, there is further flexibility in adjusting the weights and thus can be used as a replacement to multivariate regressions.

Development of irrigation and drainage networks is known as one of the most effective approaches for the optimal use of limited water resources (Abbasi., 2011). But many of the constructed networks suffer from different problems which raised from different reasons. Rahimi et al. (2011) categorized these reasons as; poor design, improper construction operation, low quality of construction materials, poor operation and maintenance, and geotechnical problems of the subgrade materials. Stilling basins are commonly used structures in order to dissipate the energy in downstream of chutes. In general, a hydraulic jump would be created at the end of the chute. The B-type hydraulic jump takes place on the positively inclined plane of a chute under particular conditions. In this condition, determination of the secondary depth and the length of the roller is essential for protecting the structures. Since there is no proper analytical method to solve the momentum equation for the mentioned condition, using of different smart techniques such as artificial intelligence was considered recently. Caralo et al. (2011) developed different models for determination of the flow characteristics for B-type hydraulic jump. Dusan etal. 2012 presented a neo- Fuzzy system for predicting the weir coefficient. Akib etal. (2014) predicted the scouring depth by using of neo- Fuzzy system. Azamathulla et al. (2012) developed a neo-fuzzy system for prediction of the sediment transport. In this research, the application of two intelligence methods including Neuro - Fuzzy Inference System and fuzzy inference system were investigated.

Soil moisture measurement is very important for better irrigation system management. One of the indirect methods for measuring the soil moisture content is to use Theta Probe device. Although the use of Theta Probe has many advantages over the other methods of measuring moisture content, but according to research conducted in most regions of the world, it has been shown that changes in the physical and chemical properties of the soil, and in general, all that affect the dielectric constant of the soil, cause an error in the accuracy of the measurement of moisture content with this device. Among the physical and chemical properties of the soil, the tissue type, the amount of clay contained in the soil, and electrical conductivity (EC) are the three main factors influencing the calibration of the Theta Probe system (Sarani and Afrasiab, 2012). The aim of this study was to investigate the effect of soil texture, irrigation water salinity (EC), and sodium absorption ratio (SAR) on the accuracy of Theta Probe device.

Providing safe conditions for water pipelines or other fluids on erodible beds is an important issue in the field of hydraulic engineering. Studies show that the installation of a plate called Spoiler on top of the pipeline increases the amount of the erosion around the pipe and its self burial stimulation. Most studies about spoiler have been done on a fixed pipe, but in reality, when the scouring hole underneath the pipe is deep enough, the pipe begins to lower as a result of the weight, at when the pipe reaches the bottom of the scour hole, the erosion process stops and then the pipe is covered with sand and buried. The self burial phenomenon has not been studied with the use of a spoiler in the case of actual displacement of the pipe, and due to the fact that the studied pipes have been fixed, the transitional and sedimentary phases have not been observed. Considering the role of pipe displacement in changing the scouring profile, the study of the spatial phenomenon of the pipe during displacement and observing the actual effect of the spoiler on the self burial performance and its effective parameters are necessary. In this study, this phenomenon has been studied experimentally.

The idea of using canoe-fishway was first proposed by Hassinger (2002) and was experimentally conducted in the hydraulic laboratory of the Kassel University. Hassinger and Kraetz (2004) presented the general principles of the canoe-fishway design. The idea of this new development was driven by the thought that a great number of thin and elastic rough elements on the one hand show a good performance in energy dissipation, and on the other hand, allows a man-driven boat to pass without being damaged. The brushes should be both firm enough to provide energy loss necessary to help fish climb easily and flexible enough to allow boats to pass through without being damaged and after the boats passing, the brushes will come back to their original state. About half of the experiments in running these facilities focuses on their application as only a fishway and the other concentrate on a hybrid structures as a canoe-fishway. Figure 1, shows an example of such fishway type (Hassinger., 2009). In recent years, the development of studies and the construction of rubber dams within walking distance to the sea on the rivers in the north of the country, necessitate the need for constructing the environmentally friendly fishway. Constructing rubber dams near the sea disrupted the fishermen commuting and thus has created social tensions (Hedayati et al., 2012). Hedayati et.al (2012) designed a canoe-fishway on Tajan rubber dam in Mazandaran province and compared it with the classic vertical slot fishway. In this study, given the importance of creating environmentally friendly fishway on rubber dams in Mazandaran province and the problems created for small fishing boats travelling on Tajan River, first the laboratory canoe-fishway model was prepared by taking into account the fish biological parameters in Tajan, Then the depth and flow velocity were evaluated.

The most common way to dissipate the water kinetic energy at the downstream of weirs , gates at chutes is to use the hydraulic jump. Hydraulic jump is a phenomenon that alters the flow regime of the state of supercritical to the subcritical with dissipating much of the flow kinetic energy and to prevent possible downstream scour of the structure. Development of the downstream scour hole of the hydraulic jump stilling basins can cause failure of the structure itself , which has been the interest of the researchers in the past. The extension of new roughened bed basin is essential to pursue and complete what previous researchers concluded for these basins.Safe and an economical design of hydraulic structures, an estimation of the maximum scour depth, and to minimization the scour dimensions is the interest of the researchers. Therefore, in this study the effect of placing the six-legged concrete elements under different lengths was investigated investigated. Covering the river bed downstream of the spillways and gates with these roughened and permeable elements can decrease the stilling basin length and expected less scour depth. These elements are tight together and placed on the bed. The covered length of the bed is equal to the length of jump on these elements. However, there is possibility in which few rows of the downstream elements are escaped because of the edge failure and therefore the roughened bed length is shortened. The main purpose of this study was to see how much exactly would be the magnitude of downstream scour depth if the covered length is decreased. .

Beach-bound plates are used to control the erosion of the walls of rivers and beaches. The nose of the plates has always been subject to scour due to the flow contact with the structure. Different factors are effective in reducing the scour. Recent research has shown that coastal and beach-bound triangular slotted panels have played an important role in reducing the scour around the nose. In this study, in order to investigate the effect of the angle, the triangular slab (slit area = 10% of the effective surface area of ​​the plate) was used at different angles of (23, 30, 40 and 60 degrees) in arched flume. Experiments were conducted under different hydraulic conditions (landing numbers 287/0, 304/0 and 322/0). The results showed that the maximum scour depth at the 23 and 40-degree angles was the lowest and the highest, respectively. The maximum stacking height is proportional to the maximum scour depth. By increasing of the angle of the plates up to 40 degrees, the maximum scour depth is farther away from the outer curve and drops sharply at an angle of 60 degrees. One of the issues in river engineering is erosion in the walls of rivers and coasts, due to the direct connection of the flow with the wall. The pattern of velocity distribution in the arc indicates the concentration of areas with maximum velocity in the lower arch and in the vicinity of the outer wall. Spoons are considered as protective structures that are used to reduce the erosion and improve the stabilization of the riverside wall. But, on the other hand, the location of the spillway in the flow path and the direct impact of the flow on the structure leads to local scouring around the nose of the spillway and, as a result, will eventually destroy the structure. It is noteworthy that the coastal triangular board of the modified state of the protective structures (in terms of appearance, degree of submergence, There is a gap in the page) for A. Judd minimum depth of scour around the nose page. . In a study by Boyan et al. (2010), in a single-seater survey of coastal triangles, the effective method for restoring river banks is to install these panels at low angles (20 and 30 degrees) and in the coastline. Therefore, due to the limited research done on the beach-bound plates, in a leading research with the installation of single-skeletal triangles attached to the coast at different angles, the angles of their placement on the topography of the bed in the 90-degree arc have been studied.

One of the important factors which has led to reduction of the sugarcane yield is short-term water stress either in growing season or in the meantime of two sequence irrigation events. Therefore, studying and monitoring of crucial parameters of sugarcane water content (canopy temperature, soil moisture and vegetation moisture) is essential. The main objectives of present study are monitoring the effective parameters of sugarcane water content, and consequently determining the correlation between two different methods for determining irrigation schedule which are based on the canopy temperature and the leaf sheath moisture measurement, in order to have an efficient irrigation scheduling as well as determining the time and the amount of irrigation, accurately.

Improper usage of unqualified water in agriculture has triggered salinity in many areas. The area of saline lands as a result of aquatic agriculture has increased 44.5 million hectares until 2005 in Iran (Banai et al., 2005). As a result of Soil salinity over the plant tolerance threshold, excessive accumulation of salt in the root zone can be a serious threat to plant growth (Silsepour and Rashidi, 2008). Reducing plant growth indices such as leaf and vegetation decreases evapotranspiration (Shani and Bengal,2005). Subsequently, the decline in plant growth will reduce crop production in many plants (Kaman et al,2008). Sorghum due to physiological characteristics such as drought tolerance, salinity, water use efficiency higher than other forage plants, relatively high yield, desirable quality, and its ability to maintain as dry forage, especially silage has a special value in arid and semi-arid regions (Zarbin and Thomas,2003). Tabatabaei and Anagli (2012) examined the effect of salinity on sorghum in the germination stage. Their study results showed, Sorghum of KFS2 cultivar is introduced as salinity tolerant sorghum due to the highest amount of germination in saline conditions. Sistan is one of the important areas for the development of sorghum in the country and in terms of cultivating corn and forage Sorghum has the fifteenth place among the provinces of the country(Binam,1388). The lack of water in Sistan plain is a serious issue. The only water source in the area is the Hirmand River, which originates from the Baba mountains of Afghanistan. The region's water crisis is due to water shortages in this river. so that, the lack of hydrometeorological water has led to the destruction of the region's agriculture. Therefore, planning for the best use of water resources is essential and inevitable. By choosing proper method for managing salty water, product performance reduction can be prevented as much as possible and reduce non-salt water demand, and by the obtained results it is possible to plan properly to increase the agricultural production in special circumstances (salinity restriction). Therefore, this study was conducted to investigate the effect of saline water management methods on yield and yield components of sorghum.

Usually protective structures are often used in coastal area and river or sea sides. In most cases, these structures are retaining walls which used to prevent the river sides erosion . Due to the contact of structures with the local soil , the study of soil interaction with structures and lateral pressure of soil is very important. Hence, the effect of particle size and compaction of backfill behind the wall is studied as an elastic analysis of wedge of body motion cantilever retaining wall in this article.