Journal of Irrigation Sciences and Engineering
Year:2020 | Volume:43 | Issue:3|Papers Count:15

Since the main site of the reservoir dams is in the mountainous valleys, the flood resulting from it will inevitably cross the mountain paths in the case of failure of the dam. The purpose of this study is to investigate the effect of the bends on the hydraulic parameters of the unsteady flow such as velocity, depth, and dynamic pressure due to dam failures. In order to achieve this goal, a flume was built with the bends. In addition, the effects of different upstream and downstream depths flow parameters were investigated. Noticeable measured parameters were: velocity, dynamic pressure and height of the wave flood due to the dam failure in 4 angles of 0, 45, 90, and 105 degrees (straight path after the end of the bend).

Estimation of reference evapotranspiration (ET0) is essential to determine water requirements of crops. In other words, to regionalize ET0 to a large area, some interpolation methods should be used (Goovaerts, 1997). A key parameter which may influence the proper performance of interpolattion methods, is the sequence of ET0 estimation process (Mardikis et al., 2005; Vilanova et al., 2012). That is why using some auxillary variables cross correlated with the main variable, could significantly improve the accuracy of interpolation methods. Therefore, this study aims to analyze the estimation process sequences while investigating spatial variability of annual and monthly ET0 in Iran. A comprehensive comparison of spatial interpolators is performed. Elevation is also used as a secondary variable in multivariate methods.

Urban storm water has often been known as a major source of pollution influencing the surface water quality in urban areas (Fu et al., 2009). The urban storm water and its economic, social and environmental adverse effects can be predicted and controlled like other natural phenomena to minimize both the induced damages and partial rehabilitation of that for water demand. If first flush happens during the precipitation, in order to prevent the pollution entering to the vital resource, control of the initial part of runoff is sufficient. In this situation, a large amount of the equipment and costs of pollution control will diminish. The prediction of an event occurrence in the future depends on the accurate analysis of the relevant variable in the past. Because the runoff quality data is random and dependent on spatial and temporal variables, the analysis of such information requires using the statistical calculations. One of the most used statistical methods based on the probability is the frequency of the occurrence or the number of times that a given parameter takes place in a specified time interval. Ni and Zn are two elements of the heavy metal group with harmful effects in unallowable concentration on human health. In Hamedan, the urban storm water, alongside the route and after getting out of the catchment outlet, has been used to irrigate the agricultural crops and vegetables. The runoff enters the surface water and penetrates to the groundwater resources. Moreover, the high ability of Ni and Zn absorption in some agricultural plants and vegetables adversely influences the humans and animals. Therefore, the evaluation of the concentrations of these two elements is so necessary.

Salinity stress has significantly reduced world crop growth and production, especially in arid and semi-arid regions (Bahadorkhah and kazemeini, 2014). Drought and salinity reduce crop productivity, especially in arid and semi-arid regions. Therefore, finding a crop which produces yield under these adverse conditions is very important (Razzaghi et al, 2011). Quinoa is a new plant with a high nutritional value that has led the World Food Organization (FAO) to call it vegetarian caviar (Seifati et al, 2015). Quinoa is a species of passionate herb (Adolf et al, 2013), and most Quinoa cultivars have the ability to grow in salinity with a concentration of 40 dS / m and even more. This amount of salinity is too high for most crops (Jacobsen et al, 2003, Hariadi et al, 2010).

Groundwater is one of the most important water supplies for domestic, industrial and agricultural use and it is the only reliable source of water in some areas. These resources have been exploited in many countries in the world. The various consequences of improper management and exploitation of groundwater have caused global concern, especially in developing countries. Due to the non-uniform distribution of precipitation and surface water resources and some advantages of groundwater such as low pollution, constant temperature etc., groundwater is at the center of attention as compared to surface water. Therefore, excessive exploitation of these resources will result in irreversible damage, such as declining groundwater level, discharge of wells and quants. To reduce the damage caused by the loss of aquifers, optimal management of these water resources is required. In order to achieve this goal, the latest scientific and engineering techniques should be used by water specialists. In this regard, the use of groundwater models and simulation techniques is one way to monitor, control and apply different management scenarios on groundwater resources. In groundwater models, it is possible to determine the response of aquifers in various stresses by defining different management scenarios. Therefore, the models can be used as a useful tool for identifying the hydrogeological system, choosing optimal management options and predicting the impact of climate parameters in the water management systems (Wang and Anderson, 1998; Chitsazan and Tavasuli, 1998). Precipitation, as one of the most important parameters in groundwater numerical models, plays a crucial role in water balance calculation. One of the weak points of mathematical models is the use of precipitation values in the calibration period to predict of the future. To solve the problem, time series models are considered as a solution. Among the specific characteristics of stochastic models is their ability to simulate climatic conditions. The most important time series model is the Autoregressive and Moving Average (ARIMA). The combined use of numerical and stochastic models can be effective to reduce forecast errors of numerical models.

According to the standard of Krenkel and Novotny (1980), the proposed concentrations of different water quality variables are categorized into four different groups. In this category, group 1 (A1, B1) represents a water quality which is suitable for all general applications. Group 4 is the worst water quality which is inappropriate for most applications. Moravej et al. (2017) investigated the water quality of the Karun River using the water quality index and GIS (Geographic Information system) time series modeling during 2007-2012. The results showed that the water quality index decreases (at the point where it joins the Dez River) meaning that lower quality of the river water is due to pollutants entering into the river at the downstream of the Dezful station. So, it is necessary to have control measures in this river. Recently, IRWQISC indicator has been presented by researchers of the Iranian Environmental Protection Agency. Hamedi et al. (2015) used the IRWQISC indicator to determine the changes in river flow volume due to seasonal variation. In addition, Azami et al., (2015) reviewed changes of the IRWQISC indicator for Tjan River. Bagherian Marzouni et al. (2014) conducted “ DO” and “ BOD” parameters in the Karun River with Q2k model. The results showed that by changing the entry points of the pollutants into the river (especially in low-flow condition) we will achieve the environmental goals for the river water. Nakhaei and Shahidi (2010), using the Qual2k model, showed that the water quality at the downstream of the Zayandehrood River is very poor due to the input of industrial pollutants. Rafiee et al. (2013) simulated the sources of pollutants input into the Gargar River in Khuzestan province, by Qual2k model. The results showed that the Qual2k model is sensitive to inflow and input pollutants such as BOD and Nitrate (NO3-N). In this study, the qualitative changes of the Dez River have been investigated using the Kerincell Standard and IRWQISC indicator in recent years. Then, the qualitative status of the river was simulated by Qual2k model. This model was calibrated and verified to forecast the water quality of the Dez River in the future.

The most important factor in the design of Chute Spillways is to control the occurrence of cavitation which is due to high velocity and negative pressure of flow. Cavitation occurs when the pressure of the fluid reaches its vapor pressure. In this condition, the fluid is evaporated and bubble is produced inside the liquid. When these bubbles arrive at a region of fluid flow with high pressure, bubbles explode and cause serious damage to structure (Iranian Water Research Institute, 2011). In Iran, the cavitation phenomenon has caused serious damage to the Karun I dam's spillway. The present study, considering the extracted results from laboratory model of chute spillway of Darian dam's spillway, investigates the probability of occurrence of cavitation and examines the reliability of this issue using FORM and Monte Carlo Simulation Method (MCSM). This model is made at a scale of 1: 50 in Iranian Water Research Institute. This embankment dam is located in Paveh, Kermanshah province, Iran. The spillway channel width is 68 meters which reaches 42 meters in convergent chute. The slope length of this chute is 300. 66 meters, with an angle of 14 degrees. In this laboratory model, in order to cope with the phenomenon of cavitation along the chute, two aerators in the form of deflector were used at the intervals of 211 and 270 at the beginning of chute. In order to study and control the occurrence of cavitation, it is necessary to provide information such as average velocity and pressure applied on the floor in different parts of the structure. Therefore, the flow velocity and the dynamic pressure were measured over it.

Dam construction has a long history in Iran. Nowadays, it seems to be the only solution to the drought crisis in the country; a method that has been abandoned in many countries, especially developed countries (Mohtashemi et al., 2014). Dam construction projects are more risky than other projects because they require high costs and complex spatial conditions (Shul and Fathizadeh, 2009). Today, in order to control, eliminate, or minimize the risks and risks to humans in the surrounding environment, special techniques and tools are designed (Jozi et al., 2012). Multi-criteria decision-making methods are a reliable tool for risk assessment and risk ranking (Mohammad Moradi, and Akhtrakavan, 2009). TOPSIS method is one of the most popular multi-criteria decision-making techniques (MCDM) (Manochehri & Shieh, 2013; Hsu et al., 2010). Therefore, it is obligatory to take steps to prepare for these risks before confronting them. Tang-e-Sorkh Yasouj Dam is aimed at exploiting maximum water resources of Bashar River and its branches to develop agriculture and irrigation. As this dam is under construction, in this research we try to prioritize the risks using the TOPSIS method based on three indicators of (risk intensity, the probability of occurrence and range of contamination).

Pipelines passing across the river to convey water, gas, and petroleum may develop local scour at the pipeline location. Scour development may cause damage due to pipe failure and disorder in utilization. The eddy currents around the pipe lead to the scouring phenomenon causing the non-uniformity of the pipeline and its fracture which will ultimately have environmental and destructive consequences. In this study, the effect of pipe diameter has been investigated. The experiments were conducted with five diameters (20, 30, 40, 50, and 60 mm) in three Froude numbers (0. 2, 0. 235, and 0. 26) under identical bed conditions. In the following part, scouring profiles were taken and the scouring progresses over time and maximum scour depth were investigated. The results show that scouring under pipe for a diameter of 60 mm has the highest and is the most progressing towards time compared to other diameters.

Construction of diversion dams in the rivers has caused many changes in these areas; so, hydraulic structures prevented the fish migration to the upstream. Then, the construction of hydraulic structures as fish-path for energy dissipation and improving the fishes passage are necessary. In the present study, asymmetrical W shaped Weir are designed with the tip angle of 40 ° , and the barriers with 30° , 60° , are designed with the tip angle of 90° . To recognize the hydraulic performance of fish-path, three physical models were designed for any barrier including: 30 barriers of asymmetrical W shaped Weir with 0. 6 relative distance, a model with 15 barriers with 1. 2 relative distance, and 10 barriers with 1. 8 relative distance. Based on the obtained results of increasing slope, flow discharge, relative distance, reducing roughness coefficients of barriers height, and dissipation energy dissipation will reduce. The square root of the ratio of 0. 87 to 0. 65 Darcy Weisbach on the slope 3 percent in the relative distance reaches 1. 8. The results of the experiments show that the overflow with a top angle of 40 degrees and the relative distance of 1. 2 would be the best conditions for fish crossings in the upstream flow.

Full irrigation is recommended for the regions with no limitation to access water for irrigating the farm lands. Due to the population increase and consequently, the increase in cultivation field’ s area, the climate changes etc., full irrigation is not possible in many regions (Kheyrabi et al., 1996). Under this condition, using the water management techniques, such as deficit irrigation, is necessary and its importance is undeniable. Deficit irrigation is an optimum procedure in producing the agricultural products under water limitation. In this technique, agricultural product decreases per unit area, but it is enhanced by increasing the cultivation fields. Deficit irrigation is a suitable procedure that allows planting to reduce the product by decreasing the water uptake. The main purpose of deficit irrigation is increasing the water use efficiency with decreasing applied water in each irrigation event. Soil infiltration characteristics are very important in the design and management of furrow irrigation systems (Foroud et al., 1996; She et al., 2014). For this reason, extensive research have been done in the field of water infiltration and soil permeability process in surface irrigation (such as measuring and estimating the infiltration changes, advance time, recession time, surface storage, subsurface movement etc. ). Soil infiltration changes over time affect the distribution uniformity of infiltrated water in the field, irrigation duration and finally irrigation efficiency in the furrow irrigation. Soil compaction and also cracking the furrow bottom after irrigation events are the main reasons for these changes, especially, after the initial irrigation events and under deficit irrigation conditions. Investigating the effect of deficit irrigation on the infiltration process and temporal infiltration changes and considering these changes in designing furrow irrigation systems is essential under water shortage condition. Therefore, the main purpose of this study was to investigate the temporal changes of Kostiakov-Lewis equation parameters under deficit irrigation conditions in different irrigation events during maize growing season.

Sugarcane cultivation has been revived in Khuzestan province of Iran since the 1960s and due to good results, gradually began to grow from north to south of this region. Currently, sugarcane is cultivated in more than 100, 000 hectares of the province's land and almost 25% of the country’ s demand for sugar is produced in this region. Regarding the very low rainfall and water resources reduction of the country in recent years, the optimal use of irrigation water is very important. Sugarcane fields in Iran due to irrigation problems such as distribution and consumption management, and the lack of continuous and uniform water supply, have high water use per hectare. In other words, the irrigation water use of farms is twice to three times of the real water need of sugarcane. Irrigation water use efficiency or WUE, which can be calculated from the ratio of plant dry matter to water consumption per hectare (Anyia and Herzog, 2004), is a very important criterion that can be of use in evaluating and improving irrigation operations and optimal water consumption. The water use efficiency of sugarcane depends on various factors such as climate, soil characteristics, irrigation management, cane cultivar and plant growth stage. Irrigation water quality, climate change, weeds and soil characteristics (high pH and low organic matter, for example) are the main factors that affect production of sugarcane in Iran. Therefore, the yield of the sugarcane is also far from the potential yield. Sugarcane fields of Khuzestan province are mainly rich in lime percentage and poor in organic matter and phosphorus. Soil pH in this region of the country is also about 8-8. 5 and uptake of some elements such as phosphorus, by plants and phosphorus fertilizer efficiency in these soils (alkaline and calcareous soils) are expected to be low (Wang and Wang, 1995). The optimum use of phosphorus fertilizer and water irrigation are essential for the quantitative and qualitative function of sugarcane plants. Due to the very low mobility of phosphorus in soil, its uptake by plants such as sugarcane is affected by the number of soil and plant factors (especially plant root characteristics). Changes in these factors can lead to reduction or increase of P uptake by the crop. Because of the role of organic compounds in improvement of mobility and phosphorus uptake, the use of organic maters has been considered in several researches. Organic compounds can play a direct and indirect role in plant factors and in phosphorous uptake improvement, yield increase and finally water use efficiency improvement

Wave breaking can occur in dam break phenomenon. These waves can be summarized as an uncontrolled release of water flow instantaneously from rest by the sudden removal of a vertical barrier that initially contains water. This occurrence usually causes huge loss of lives and destructions of properties and environment. Therefore, prediction of water level position, velocity and pressure is essential. Recently meshless methods have been used for numerical modeling of free surface flows. One of the oldest meshless methods is the Smoothed Particle Hydrodynamics (SPH). This method is robust to simulate problems with large deformations. Furthermore, SPH method has used successfully to model the fixed-bed dam break waves on a dry-bed and wet-bed downstream channel (Lee et al. 2008 and Khayed & Gotoh, 2010). SPH simulations of the incompressible flows can be performed by two methods: 1) approximately simulating incompressible flows with a small compressibility, namely Weakly Compressible SPH (WCSPH); 2) simulating flows by enforcing incompressibility, namely Incompressible SPH (ISPH). In WCSPH method, the flow is considered as slightly compressible, with a state equation for the pressure calculation (Monaghan, 1994). In ISPH method the pressurevelocity coupling is generally achieved by the projection method (Hu and Adams, 2007). This paper presents a two-dimensional ISPH model to simulate dam break waves in a bed with a hump.

Over the past years, population growth, the development of industry and agriculture have led to an increase in surface water and groundwater resources. Excessive withdrawal and severe drop in water levels as well as land degradation in some parts of the country have been to the extent that the resources are at risk, the situation is critical and this has made sustainable use efforts a must. For this reason, a comprehensive management plan is needed to improve feedback and to make accurate management decisions to maintain the balance and sustainability of water resources. Adopting sound management decisions requires proper, accurate, and scientific knowledge of the conditions of the water resources of the region. In discussing the management of groundwater resources and maintaining the balance and stability of aquifers, understanding the performance of the table in normal conditions, as well as simulating the effects of drainage or nutrition is necessary. Over the past years, many indicators have been developed for a quantitative assessment of water resource vulnerability. Therefore, selecting a criterion to demonstrate the correctness of the water situation can bring policy decisions closer to scientific decisions (Kang and Lee, 2011). The WSI index was successfully used to assess the sustainability of water resources in the Geum Basin in South Korea (Rachmad et al 2014). In the assessment of the sustainability of the area in the Batang Merao region of Indonesia in 2006-2011, four indexes of hydrology, environment, life and politics were measured. The purpose of this study was to provide an integrated watershed management framework and to help sustain the area. This study was conducted to investigate the stability of groundwater and surface water of Najaf Abad area. In order to control the crisis and sustainable management of the aquifer in the studied area, review Najaf Abad aquifer management and control solutions and prevent further crises resulting from unwanted harvesting, an analysis of water resources sustainability indexes has been done. Also, to investigate the sustainability of water resources in this area, three indicators of water consumption to renewable water (C / RW), available water (WAI) and water stress (WSI) have been used. The results of indicators showed the inconstancy of water resources in the region. In the next step, aquifer modeling was done using the MODFLOW code in Gms software. The purpose of this model was to validate the findings of sustainability indicators. The results of modelling and survey sustainability were matched by indexes.

Restrictions of surface water resources in arid and semiarid regions, along with increasing population and agricultural development, have led humans to exploit groundwater reserves as an important water resource. It is in arid and semi-arid regions that the change in groundwater quality caused by mismanagement of groundwater is an introduction to the degradation of water resources and other resources, both directly and indirectly. Recently, numerous studies have been conducted on water quality with different models (Farajzadeh and Mohammadi, 2010; Kholghi and Hosseini, 2009; Mokarram et al., 2019; Taghizadeh Mehrjerdi et al., 2008). Mehrjerdi et al. (2008) explored the application of chemical parameters such as EC, TDS, and CI in groundwater quality zoning of Ardakan-Yazd plain. Sanches (2001) and Thoradeniya et al. (2019) have also investigated water quality assessment and zoning. Therefore, studying and evaluating the quality of groundwater and identifying suitable sites for groundwater recharge in these areas can help with proper management of water resources. The purpose of this study was to evaluate groundwater quality using fuzzy method in Kohgiluyeh and Boyer Ahmad, Iran, in different geomorphological units. In order to determine groundwater quality in the study area, parameters such as Na, electrical conductivity (EC), Ca, Mg were measured in 30 sample points.