Iranian Water Research Journal

Abstract The main part of available water resources is consuming in agriculture. So, irrigation networks play an important role in the optimal use of these resources. Gates are one of the most common water structures in distribution canals, which transport and deliver water to consumers, to control the flow rate or water level. Determining the relationships governor on these structures can improve the performance of open canals and therefore prevent water loss. In the present study, an experimental investigation has been conducted on elliptical Lopac gates. This gate is a combination of a Lopac gate and elliptical sharped edge weir. The reason for the using of such combination is to achieve a simple and hydraulically constructed gate that has a higher performance than commonly used models. The elliptical Lopac gate is applied as a new structure for water level adjustment. Some advantages of this structure could be mentioned as: overflow behavior and better possibility for water level control, simultaneous passage of sediments and floating bodies, low power requirements, and ease of automation of the structure. These advantages have recently attracted the attention of water managers to apply the structure in irrigation canals. These overflow structures act as weir in terms of hydraulic behavior. The Lopac gates are similar to saloon doors, hinged at vertical walls of the canal, which regulate the upstream water level for different discharges by adjusting their opening angle. So far little studies have been done on these types of gates. In this study, by using of energy relationship and laboratory results, the characteristics of the flow and the equation of discharge and the gate discharge coefficient in free flow conditions were investigated and the new type of this gate, -called elliptical Lopac gate- were mentioned. The experiments of this study were conducted in Hydraulic Laboratory of the Faculty of Water Engineering, Shahid Chamran University of Ahwaz. After examining all the methods of testing and different types of flumes and channels, a rectangular flume with glass wall and metal floor with the length, width and height of 10.5, 0.8 and 0.6 meter, respectively, was selected for tests. In order to obtain the opening angles, a pair of PVC picket were cut at the desired angle and then applied. Also, for testing in two free and submerged modes, a fiat sliding gate at the downstream of the channel was installed for this purpose. In free flow conditions, five different discharges (20, 30, 40, 50 and 60 l/s) were tested for 5 different opening angles (20, 22.5, 30, 37.5 and 45 degrees).The flow discharge was measured by an ultrasonic flow meter with the accuracy of ± 1 l/s. In each experiment, for a given discharge and the angle of opening, the depth of water was taken on the upstream of the elliptical Lopac gate, at the 7 sections in the length and 5 points in width. After dimensional analysis of the effective quantities on the discharge coefficient of elliptical Lopac gate, the effective dimensionless parameters were obtained. These quantities include: Froude number, Reynolds number, Flume width to the upstream water depth ratio B/y, and Opening ratio b/B. The Reynolds number expresses the effect of viscosity forces. This factor plays a role only for large gate opening angles, where the upstream water depth decreases. According to the tests in the range of turbulent flow, the impact of the viscosity force was negligible. In the following, due to the free flow condition, a theoretical relationship was determined for discharge by the energy equation. Subsequently by using a regression on the results of the experiments, acceptable propositions were estimated for the discharge equation and the discharge coefficient. The discharge coefficient in free flow conditions and for both types of rectangular Lopac gate and elliptical Lopac gate was a function of the gate opening ratio and its value increases with increasing gate opening. The observations showed that the most effective dimensionless parameter on the discharge coefficient was the opening ratio. The two parameters of the Froud number and the ratio of flume width to the upstream depth were both the function of the opening ratio. This relative on provided similar accuracy as the main equation with Root Mean Square Error of 0.00185, Mean Absolute Percentage Error of 3.143%, and Relative Error of ±10%.

Abstract Population growth, urbanization, and industrialization of human communities have negative effects on basin’s hydrology. Besides, expanding the impervious area increases the amount of surface flow coefficient, runoff and flood volumes. According to land use changes, one of the best management activities is the use of surface runoff for different purposes in urban area. The main purpose of this study is to investigate the use of surface runoff for irrigation of green spaces. Due to the high volume of water demand in the 9th district of Mashhad City, Iran, this study proposed the utilization of the existing detention ponds as well as design new detention ponds, for irrigation of the green spaces during the flood events. The case study is located in Ab-o-Bargh basin, with about 770 hectares area in Mashhad, Iran. In order to determine the dimensions and length of the canals, the maps were obtained from the Information Technology Organization of Iran (ITO). According to field visits as well as analyzing the digital elevation maps, the study area could be divided into 88 sub-basins. Infiltration coefficient was selected based on the land use of the basin (residential, street, etc.). Manning coefficient was determined as 0.015 according to the software help of GIS for the channels and its coverage for each sub-basin. The effective catchment width with a suitable approximation was obtained from dividing of the basin area to the channel length. For calculating the average slope of the basin, the most accurate method was the use of slope pattern algorithm in GIS software. Channel slope was calculated similarly with the start and end elevations of each channel. Horton and Keirpich methods were used to estimate the infiltration and concentration time, respectively. The IDF curve of Mashhad was used to determine the return period and rainfall pattern. Two-year return period was considered for simulating flood distribution in the studied area. The prerequisite for determination of design flood period is to select an appropriate rainfall return period. In this regard, the average daily water demand determined for irrigation of green space was equal to 3.936 m³ per day. The volume of the existing reservoirs was calculated about 1305 m³. As the first step for modeling the studied area, all sub-basins and channels were defined in AutoCAD software and introduced to model, separately. In the second step according to the characteristics of each layer, the physiographic data such as area, basin width, average slope, digit elevation, manning's coefficient were defined in the model for each layer. Afterward as the third step, ASSA software was employed for simulating different features of the studied area. Then in the fourth step, the required physiographic and topography data were imported from GIS to this software. After that, precipitation data, Horton coefficients, and the other metrological and hydrological data were introduced into the model. After running the model, the discharge and the total runoff volume of flood were estimated equal to 6.55 m³/s and 17531 m³, respectively. The total numbers and volume of available tanks were equal to seven and 1305 m³, respectively. Among the existed tanks, two tanks had 9*9*4 m³, two tanks had 6*6*3 m³ and the other three tanks had 7*7*3 m³ dimensions. The dimensions of the proposed detention ponds were three tanks with 9*9*4 m³ and three tanks with 7*7*3 m³ dimensions, with a total volume of 1,413 m³. Results of the model showed that without detention ponds, the runoff volume and the peak were equal to 17,531 m³ and 6.55 m³/s, respectively. Using the available detention ponds in the studied area, leaded the total volume of runoff to be decreased from 17531 to 16298 m³, which demonstrated 7% decreases in the flood volume. Peak of runoff was also decreased to 5.71 m³/s, indicated 13% decreases. Moreover, by adding the proposed detention ponds, the amount of outflow runoff was decreased to 14,900 m³, which demonstrated 9% decreases in comparison with using the available detention ponds and 15% decreases in comparison with no detention pond state. Eventually, regarding the results obtained in the current study, it could be acclaimed that use of run-off detection ponds can reduce peak flow and outflow run-off volume from the basin, as well as economic benefits for irrigating green space.

Abstract Water Distribution Networks (WDNs), as one the most important infrastructures, are very vulnerable to accidental or deliberate contamination intrusion, due to their accessibility and extension over urban areas. In recent years, there has been increased interest on protecting these networks from possible contamination risks with the aim of mainly minimizing the harmful effects on public health and security. Attacks on WDNs can be divided into three categories of cyber-attacks, physical attacks, and biological and chemical attacks. One of the most important threats to WND is a deliberate chemical or biological contamination injection due to uncertainty on both location injection and its consequences. Therefore, it is essentially required to take optimal activities for minimizing public health and economic consequences and restoring the system to normal operation conditions. These activities mainly consist of any combination of system isolation, public notification, flushing and finally providing short-term and long-term alternative domestic water supply. In this study, an embedded approach consists of EPANET simulation model and multi-objective optimization model namely Non-dominated Sorting Genetic Algorithm-II (NSGA-II) was used to derive the optimal operational response actions following the contamination detection in the network. EPANET 2.0 simulation model is used to calculate the spatial variation of contamination in the network at different time step. EPANET is open free software that easily linked with optimization model via its toolkit. NSGA-II optimization model develops a trade-off between two common objectives functions in consequence management modeling. NSGA-II optimization model sorts the population of different chromosomes based on their non-dominance over the other solutions. According to the number of dominated solutions, a rank was assigned to a particular chromosome in the current population. Moreover, a crowding distance was considered to preserve diversity among chromosomes in a population. In this research, to illustrate the performance of the proposed methodology, Net3 from EPANET 2 was employed. The system consisted of 117 pipes, 92 nodes, three tanks, two pumps, a lake and a river. A deliberate contamination was injected into the network at node 101 for six hours (08:00 to 14:00). As suggested in Ostfeld and Salomons (2004) study, five sensors at nodes 15, 35, 145, 225 and 255 were considered for early warning contamination detection. The first sensor was detected the contamination about 11:00 and one hour was assumed for initiating response actions. Therefore, optimal operational response actions were started at 12:00 and continued until the end of simulation time (24:00). It was assumed that all hydrants were in class C (red) with discharge rate of less than 1900 liter/min (proposed by National Fluid Power Association). Two main objective functions were considered in this study for NSGA-II multi-objective optimization model. The first objective was to minimize the number of operational activities that include open or close the valves and hydrants in the network. To control the consequences of contamination in the network, the polluted area was isolated by the valves to prevent the spread of contamination and the discharge of contaminated water through fire hydrants. Hence, the optimization model had binary decision variables including hydrant opening and valve closing. Total number of decision variables was equal to the potential number of valves and hydrants. In this study, optimal operation activities were selected among 51 potential valves and hydrants. The number of operational activities was limited to 15. The second objective was the minimization of consumed contaminated water by multiplying the concentration of pollutants in consumed contaminated water volume. Obtained results showed that without any operational response action, consumed contamination mass was equal to 80.38 kg. Whereas, consumed contamination mass was decreased to 58.04 kg with 15 optimal response actions. Optimal values for different parameters of multi-objective model were obtained by sensitivity analysis through the number of populations and genes, as well as crossover and mutation rates. The optimal selected values for the optimization model were 30 populations, 150 genes with a crossover and mutation rate of 0.85 and 0.15, respectively. Moreover, in this study, sensitivity analysis was carried out on start time of consequence management (between 11:00 to 16:00 with one hour time interval) for evaluation of its effect on the second objective function. Consumed contamination mass at different start time of consequence management between 11:00 to 16:00 with hourly time step were equal to 52.20, 59.27, 61.18, 62.17, 67.47 and 70.17 kg, respectively. Ultimately, the earlier the operational activities starts, the more the consumed contamination mass decreases. 

Abstract Precipitation forecasting is an essential tool for optimal management of water resources and flood forecasting. The numerical weather prediction (NWP) models play a major role in weather forecasting. They predict the future state of the weather by mathematical modeling of the atmosphere behavior, based on its current condition. However, the accuracy of the NWP models is still a challenging issue and its improvement is the main goal of the operational prediction centers. In weather forecasting by using NWP models, there are several resources of uncertainty such as intrinsic chaotic behavior of atmosphere dynamic system, errors in observational data and initial conditions which are almost impossible to remove. Ensemble systems are used to quantify these uncertainties. Instead of only one deterministic forecast, an ensemble system is created by several forecasts obtained from perturbation of the initial conditions, physical schemes or dynamical core of the NWP models. Ensemble systems are widely used by the meteorological communities especially for medium-range weather forecasts, short range and even ultra-short range weather prediction. A probabilistic forecasting of flood and extreme precipitation can be produced by an Ensemble Prediction System (EPS). However in practice, ensemble forecasts are generally under-dispersive and thus are not calibrated, especially for meteorological parameters near the ground level. Several statistical methods have been proposed to post-process the EPS outputs. After post-processing the EPS outputs, the biases in both location and dispersion are removed using a historical database of ensemble forecast errors, and then a predictive probability density function (PDF) can be estimated. The most popular ensemble post-processing methods are Bayesian Model Averaging and Ensemble Model Output Statistics. In BMA method, based on the error statistics of each member during a training period, a PDF is first fitted to every ensemble member forecast. Then the predictive PDF is estimated by weighted averaging of members' PDFs. Logistic regression is a nonlinear regression method that is well suited to probability forecasting, i.e. situations where the predictand is a probability rather than a mea- surable physical quantity Logistic regression is a nonlinear regression method that is well suited to probability forecasting, i.e. situations where the predictand is a probability rather than a mea- surable physical quantity Logistic regression is a nonlinear regression method that is well suited to probability forecasting, i.e. situations where the predictand is a probability rather than a mea- surable physical quantity Logistic regression is a nonlinear regression method that is well suited to probability forecasting, i.e. situations where the predictand is a probability rather than a mea- surable physical quantity Logistic regression is a nonlinear regression method that is well suited to probability forecasting, i.e. situations where the predictand is a probability rather than a mea- surable physical quantity Logistic regression is a nonlinear regression method that is well suited to probability forecasting, i.e. situations where the predictand is a probability rather than a mea- surable physical quantity LR was among the first statistical methods that were used to post-process the EPS output. Logistic Regression (LR) was extended to provide a full continuous predictive PDF. In the extended Logistic regression (ELR), the predictions and thresholds are used as additional predictor variables. In this study, an EPS was developed using eight different configurations of the WRF model to produce probabilistic precipitation forecast over Iran. Initial and boundary conditions for WRF were provided from the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) forecasts with a horizontal resolution of 0.5. The BMA and ELR methods were used to calibrate the probabilistic forecasts of rainfall in the fall and winter of 2016-2015 over Iran. The data were separated to two parts of equal periods. The first and second parts of the data were used for training and test respectively. The calibrated probabilistic forecasts were assessed using reliability and Relative Operating Characteristic Curve (ROC) diagrams, ROC Skill Score, Ranked Probability Score (RPS) and Ranked Probability Skill Score RPSS at the thresholds of 0.1, 2.5, 5, 10, 15 and 25 mm. For ensemble probabilistic forecasting, BMA was used as a statistical technique that combines inferences and predictions based on individual ensemble members, so as to yield a more skillful and reliable probabilistic prediction. It was assumed that the forecast PDF of a weather variable y is conditional on the ensemble member forecast : . The BMA ensemble forecast is essentially an average of forecasts based on individual members weighted by the likelihood that an individual forecasting model is correct given the observations. LR was used as a nonlinear regression method that is well suited to probability forecasting, i.e. situations where the predicted is a probability rather than a measurable physical quantity. The mathematical form of the LR equation yields ‘S-shaped’ prediction functions that are strictly bounded on the unit interval (0 <p< 1). The results showed that the application of BMA and LR methods have improved the reliability of the raw ensemble significantly for 24-, 48- and 72-hour forecasts at different thresholds. Moreover, it was observed that application of BMA improved the raw ensemble, such that the reliability and ROC diagrams were improved significantly. Moreover, the amount of improvement for BMA was slightly higher than that of the LR method. The RPS score of BMA method for the 24-48- and 72-hour forecasts was reduced by 45, 40 and 38 percent, and for LR method the RPS score had the reduction of 40, 36 and 34 percent, respectively. For 24-hour forecasts, the RSS of BMA method was improved by 85, 87, 87, 83, 81 and 79 percent and the RSS of LR method was enhanced by 85, 85, 81, 72, 64 and 59 percent at the thresholds of 0.1, 2.5, 5, 10, 15 and 25 mm, respectively. Similar results were achieved in 48- and 72-hours forecasts. Generally, the result indicated that using BMA method for calibration of raw ensemble system for precipitation forecast was justified for operational purposes.

Abstract The geographical map of the countries shows that the political boundaries are not aligned with the water basins. The existence of transboundary rivers has led to divergences over the water availability of these rivers in many countries. Competition and conflict have been created for gaining more profit. What makes the competition over the border waters more serious is the nature of the international relations of the upstream and downstream Countries that transform water use into political leverage. In Iran, the limitation of fresh water resources and the need to plan for the proper utilization of diverse water resources capacities, highlight the importance of obtaining the right of transboundary rivers. This part of the water is effective in preventing pressure on internal resources, some natural damage caused by drought and water scarcity, and some internal conflicts between basins. Considering the research done on transboundary rivers, which have often been politically or geographically examined, So far, no research has been conducted on the development and prioritization of strategic policies for the extraction of the water rights of Iranian transboundary rivers. In this study, the strategic policies that the government can adopt to obtain the water-right of the Iranian transboundary rivers were determined based on the expertise of experts in the fields of water sciences, environment, geomorphology, political sciences and middle managers of the water industry. To this aim, a questionnaire was prepared in with 5 Criterion and 12 strategies. Then, its validity was evaluated by the relevant experts. After conversion of qualitative values to 20 quantitative questionnaires, the reliability of the questionnaire was confirmed by Cronbach's alpha in SPSS statistical software. This coefficient was calculated 0.735. The AHP method was then prioritized by Export Choice software. The ANP method was prioritized in the MATLAB programming environment. Then, the results of both methods were compared. In the sensitivity analysis by the Three Antifilo method, the numerical value of the most sensitive criterion was calculated and then the weight of the other criteria was modified accordingly. The threshold percentage and change in weight of the criteria were determined. Afterward, the sensitivity coefficient of the criteria was calculated and the numerical value of the most sensitive criterion was modified. The other criterion was modified based on the modified critical criterion. To analyze the sensitivity of strategic policies the fallowing steps were taken: First, numerical values of threshold weight and its percentage and critical degree were calculated; Second, sensitivity coefficients of strategic policies, which are the inverse of the most critical strategies, were calculated and compared; Third, The numerical value of the most sensitive strategy was corrected; and at the last step of this method, the values of each strategic policy were normalized to the most sensitive criterion. The results showed that the two criteria of benefit and timing with weight of 26.26 and 0.13 were in the first and last priority, respectively. The final prioritization was similar in both ways, except in the second, fourth and ninth strategy of the initial table. The strategy of controlling more outflows from the country and applying pressure to reduce tariffs for importing high-quality virtual water into the country, in the AHP method with 11.88% and in the ANP method with 11.08%, placed as first priority. In addition, A₁₁ strategy was the last priority with 8.17% by AHP and 6.11% by ANP. Also, profitability with the coefficient of 0.185 was introduced as the most sensitive criterion. Based on it, the weight of the other criteria was modified. Therefore the prioritization of the criteria remained unchanged in comparison with the results of the sensitivity analysis of strategies based on each criterion separately. It showed that the most sensitive strategic policy is the strategy of cooperating with neighboring countries for better access to seawater, changing the pattern of cultivation with low water requirement and thriving in other economic potentials of the neighboring country to reduce the tendency for highly water-intensive activities. Its regarding coefficient was 0.178 which is the highest value, based on the profitability criterion. In the final step after normalizing the weights of the strategies according to the critical criterion, the prioritization of the strategies with little change in weights also remained unchanged. Advancing the first policy will be effective in short term, but will not entail economic costs, and it may create political strain on the diplomatic relations of the two countries. Advancing the second priority will be more time consuming, but not, economically and politically costly. Like the first priority, the second can improve Iran's political standing in the region, while it can cost diplomatic means on the country. The last priorities are the strategic policies that are economically costly for the country and have a negative impact on the other two countries' relations.

Abstract Environmental consequences of deep subsurface drainage in irrigated lands of arid and semi-arid areas with shallow saline groundwater have posed a significant threat to sustainable crop production. In this regard, controlled drainage has introduced as the next logical step towards improving water management in irrigated agriculture and reducing the environmental impacts of subsurface drainage flow. Besides, the collected data from field experiments in combination with deterministic agro-hydrological simulation models offer the opportunity to gain detailed insights into the agricultural system behavior in space and time. Deterministic soil and water balance models like field scale Soil-Water-Atmosphere-Plant (SWAP) quantify all water and salt balance components and their interactions in the Soil-Water-Plant- Atmosphere continuum during the simulation period. The accuracy of these predictive models depends upon proper identification of the required model input parameters. Also, in the current edition of the SWAP model, the simulation of controlled subsurface drainage is not implemented. Despite of the capability of field-scale agro-hydrological models to quantify the interactions between soil water flow, salt transport, and crop growth, application of these models in actual operational conditions of the current case study has faced with a significant hurdle for reliable characterization of the farming system. Because of the large area of the sugarcane farms Khuzestan, southern Iran, the complement of a single irrigation event may take up to more than five days. Hence, representing the agricultural system as a single soil column would be questionable. The main objective of this work was to enable the application of such models under actual operational conditions in large fields with surface and/or subsurface drainage systems, with combinational free/controlled subsurface drainage management. To this aim, a distributed agro-hydrological modeling scheme with sub-daily calibration capability was developed through combining a modified version of the field scale SWAP model with an improved variant of Unified Particle Swarm Optimization (UPSO) algorithm. The source code of the SWAP model was modified and extended to consider the duration of the irrigation events, simulation of intra-daily reference evapotranspiration, intra-daily precipitation interception, ratooning, and implementation of subsurface controlled drainage during the simulation period. To calibrate the unknown model parameters, the model was coupled with an intra-daily inverse modeling scheme developed via an improved variant of Unified Particle Swarm Optimization (UPSO) algorithm. The developed modeling scheme was applied to a dataset collected from a field with a combinational free/controlled (70-cm depth) subsurface drainage management located at Shoaybiyeh Sugarcane Agro-industrial company farms. The simulation was performed from 2010-07-19 to 2011-12-11 (481 days) for planted sugarcane (CP48-103 cultivar). A soil profile of 550 cm depth (depth of impermeable layer) was specified during simulations. The soil profile was divided into two layers. To consider inhomogeneity of irrigation scheduling at different parts of the studied field, the field area was divided into ten homogeneous simulation units (with a dimension of 84.5 ´ 250 m), termed as hydrotopes. The hydrotopes have similar agro-hydrological properties except for irrigation scheduling. The model was calibrated, using the measured soil moisture profile, soil solute concentration profile, groundwater level, subsurface drainage outflow, drainage outflow salinity, Leaf Area Index (LAI), cane yield, and sucrose yield in a parallel manner. The weighted average of simulated values derived for each hydrotopes was compared with the corresponding measured data. Totally, 45 parameters were estimated through inverse modeling scheme. The accuracy of the model in calibration and validation stages was evaluated, using the mean error ME, the mean absolute error MAE, the root mean square error RMSE, normalized root mean square error NRMSE, Pearson's correlation coefficient r, and Nash-Sutcliffe model efficiency coefficient EF. The results demonstrated the success of the developed modeling scheme in retrieving the measured soil moisture, groundwater level, subsurface drainage outflow (with an EF of 0.875, 0.933, and 0.751 for calibration dataset; and 0.804, 0.760, and 0.739 for validation dataset, respectively), soil water solute concentration, subsurface drainage outflow salinity (with a NRMSE of 0.092 and 0.119 for calibration dataset; and 0.142 and 0.042 for validation dataset, respectively), LAI, cane yield, and sucrose yield (with an EF of 0.996, 0.996, and 0.999, respectively). Except for drainage outflow salinity and cane yield, the lack of correlation was the main source of disagreement between measured and simulated data. In the case of measured subsurface drainage outflow salinity, the model deficiency to retrieve the temporal oscillations in measured data was the main source (with a contribution of 93.225% and 89.645% in overall disagreement for calibration and validation stage, respectively) of disagreement between measured and simulated data. Based on the simulated solute balance components throughout the simulation period, ~ 33.72 ton salt ha-1 was added to the soil due to saline irrigation water, and ~ 54.94 ton salt ha-1 was discharged into the receiving water bodies via field drains. Ultimately, the calibrated and validated model can be used as a helpful decision support tool for deriving the integrated irrigation and drainage water management scenarios in the study area.

Abstract Urban flooding is generally caused by some unexpected phenomena such as dam failure, torrential rainfall or tsunami waves moving toward the urban areas. Numerical methods have been used for many years to model the inundation problems over urban areas. Computational and mathematical approaches can be employed for several reasons. First, they can be considered as a reliable approach that allows modellers or engineers to predict the flooding extent into the cities and mitigate the hazardous effects on civilians, infrastructure facilities and constructions. Second, the experimental and geophysical data obtained for the previous inundations around the world are regional and strongly depend on the geographical and local conditions for the inundated area, and therefore cannot be applied for the other districts. Finally, the numerical simulation can be used for the large computational domains and can help to design the flood capacity for the conveyance channels or underground pipe networks devised for collecting free-surface flows within the cities. Modeling of water waves within a sewer network is a contemporary research area where the main goal is developing an accurate sewer design and planning tools. The prediction models should ideally be able to simulate the unsteady flow regime within the sewer network as well as the flow field created inside the manholes which link the surface flows to the sewer system. Manhole is one of the sewer network components which conveys surface flow to underground network. Inspection of the flow behavior when propagates and enters the sewer network is therefore momentous. In general, modeling of such flows is only possible by means of Navier-Stokes equations with free surface capability. However, for a large domain and three-dimensional problem, the computational demands are rather high and prohibitive. Besides, the shallow water equations (SWEs) are a well-established set of conservation laws that approximate the hydrodynamics of flows in shallow water domains, where the depth is small compared to the overall plan dimensions. The SWEs are depth-averaged with the assumption of hydrostatic pressure and are much more computationally efficient for simulation of inundation over large areas. Herein, the shallow water equations (SWEs) were used as a proper substitution for Navier-Stokes equations to predict the wave movement. In order to solve the SWEs, a modified wave propagation algorithm with complex wave interaction capability over a dry-state was utilized. Moreover, an ODE system of equations was utilized to anticipate the flow action through the manhole. Then, these equations were coupled with each other to unify the approaches. STAR-CD software was utilized to validate the results of abovementioned approach. The STAR-CD is the commercial Navier-Stokes solver based on the VOF (volume of fluid) approach which models free-surface motion quite generally, despite considerable computational expense. To calculate the error between SWEs results and STAR-CD solution, Root Mean Square Error (RMSE) method was used. RMSE is the standard deviation of the residuals (prediction errors). Residuals are a measure of how far from the regression line data points are. In other words, it shows how concentrated the data is around the line of best fit. First, to test the ability of the proposed approach, the interaction of dam break flow with two surcharged flows released on a dry bed was studied. This test case was important as it shows the ability of the proposed method in modelling multiple wave interactions over the dry-state. Then a 1D sewer network consisting of one manhole and an underground channel was considered and flowing water inside the system was modelled. For all test cases, the achieved numerical results were compared with those of the 3D Navier-Stokes solver, STAR-CD, which was setup to use the two-phase VOF solver for capturing free-surface. In addition, a dimensionless number named Manhole Number (MN) was defined based on the height of manhole and underground channel, manhole width and the velocity of the water entering the manhole. Moreover, many experiments were performed by changing the mentioned effective parameters to create a range for the manhole number. This range showed that the defined numerical solver gives accurate predictions if the MN is satisfied. Results were shown that if MN ≤ 0.98, the error obtained using RMSE method will be less than one percent and tends to zero. The simulation results indicated that in all investigated cases, a good agreement was observed between the solutions of the proposed method and the Navier-Stokes solver. This was despite observing some inherent drawbacks such as inability to capture cavities and model free-fall problems in the SWEs solutions.

Abstract According to the arid and semi-arid climate conditions and insufficient rainfall in Bushehr province, southern Iran, water deficit is the most important limiting factor for agricultural development in this region. Therefore, the use of modern irrigation methods to prevent water loss in this sector is essential. Drip irrigation is of particular importance due to some specific technical characteristics and proper conditions that it provides in the root zone in terms of nutrition, ventilation, moisture and salinity. In recent years, use of drip-tapes to irrigate row crops has extended, due to some comparative advantages. As well, drip-tape irrigated tomato fields have developed in Bushehr province and many efforts have been made by the government to support the farmers. Therefore, the present study was designed to evaluate the effects of different modes of drip-tape installation (surface and subsurface) on yield and irrigation water use efficiency of tomato in the region.
This study was carried out during three consecutive cropping seasons (2008-2011) at the Agricultural and Natural Resources Research Center of Bushehr (51° 32? E and 35° 51? E; elevation of 100 meters above sea level). The experiment was conducted as split plot in a randomized complete block design (RCBD), with four mods of drip-tape installation in three replications. The treatments included different installation of drip-tape: on soil surface (T1); within the small surface furrows (T2); in the depth of 10 cm from soil surface (T3); and in the depth of 20 cm from soil surface (T4). Accordingly, a drip-tape irrigation system was designed and installed based on the objectives of the experiment and arrangement of the treatments. The amount of irrigation water was calculated based on FAO-Penman-Monteith equation. The area of each experimental plot was 28 m2 and consisted of two laterals of 10 m long and 140 cm apart. A volumetric flow meter was used to control the irrigation of plots. In order to investigate the effect of considered treatments on salt distribution in root zone, soil was sampled using a manual auger in two stages: once in mid-growing season (after the end of winter rains) and again after harvesting. Sampling was done at horizontally distances of 0, 30, 60 and 90 cm from drip-tape and at depths of 0-30, 30-60 and 60-90. Also, for investigating the effect of the treatments on the uniformity of water distribution through the drip-tape, 8 apertures at the beginning, one third, two third and the end of the drip-tapes were selected. Then, sampling cans were placed at the selected points. By measuring the water collected in the cans, Christiansen coefficient of Uniformity (UC) was calculated using the obtained data.
Generally, with subsurface installation of drip-tape, fruit yield and IWUE increased, compared with surface treatments. However, with increasing depth of drip tape placement from 10 cm to 20 cm, fruit yield and IWUE decreased. The highest fruit yield (48.0 t/ha) and IWUE (9.4 kg/M3) belonged to T3. However, this treatment had no significant difference with T2. The lowest fruit yield and IWUE belonged to the T1 treatment, which had the lower soil moisture content due to surface runoff and increased evaporation losses. In the T2 treatment, which is a common practice of farmers, the wetted area was limited to the floor width of the furrow. So, lateral expansion of wetted area in T2 was less than that of T1 treatment. Also, in T2 treatment, irrigation/rainfall water was stored in furrows, instead of producing runoff, and then gradually infiltrated into the soil. This feature helped to store moisture in the root zone and salt leaching from the soil. Therefore, the treatments of T3 and T2 had not significant difference from each other. Christiansen coefficient of Uniformity (UC) ranged from 86% (in T2 and T3 treatments) to 89% (in T4 treatment), but these changes were not significant. This was due to the use of appropriate water, proper filtration system and the use of new drip-tapes at each year.
Salt distribution in soil profile was different under the evaluated treatments. Generally, in the middle decades of the growth season, due to the coincidence with winter rainfall and salt leaching with rainwater, salt accumulation in the surface layer was lower, but in the late decades, due to the end of the rainy season, premature heat and increased evaporation need of atmosphere, the salt movement toward the surface layer increased. For this reason, at the end of the growing season, in almost all evaluated treatments, the highest soil salinity was measured in surface layer of the soil (0-30 cm), at a distance of 30 cm from the location of the drip-tape. According to the results discussed, because of easy installation and management of drip-tape, T2 treatment preferred to subsurface treatments for the experiment location and similar regions.

Abstract The results of most climate models, under diffusion scenarios (RCPs), indicate an increase in global temperature by the end of the 21st century, compared with the period 1850-1900 (IPCC, 2014). Considering the perceptible effects of climate change on meteorological parameters and then water resources, simulation and prediction of runoff in watersheds is extremely important. When it is necessary to simulate only the flow at the outlet of the watershed, the conceptual rainfall-runoff models (such as the IHACRES model) are preferred; because, they require less computational effort and input data, as well as provide a good response. A review of several studies on the effects of climate change on different systems in future periods shows that although many sources of uncertainty affect the final results, usually these sources of uncertainty are ignored in the calculations, which reduces the accuracy of the results. In some studies, despite the attempt to consider the uncertainty of AOGCM models in the calculations, all the AOGCM models have been applied with the same weight. Also, in most studies on climate change, limited types (less than 10) of climate models has been used. Therefore in the present study, 23 climate models were used to predict future climatic conditions, in order to reduce the uncertainty of these models. The superior model was selected using the weighting method. Then, using the IHACRES model, the effects of climate change on the Shirin (Azam Jareh) river runoff, with emphasize on the uncertainty of AOGCM models was studied in the forthcoming period of 2020-2040.
Shirin River (Azam Jareh) is one of the main tributaries of Dalaki River, which originates about 70 km from the southern slopes of Arjan Plain and its tributaries include Sarkhoon and Tang-E- Gachi. The average long-term flow of Shirin River (Azam Jareh) is 11.3 m3/s and the average annual precipitation is 761 mm. In order to quantify the uncertainty in this study, the output of 23 AOGCM models was evaluated, using weighting method and calculation of performance criteria. The best selected models were GFDL-ESM2G, GISS-E2-R, MPI-ESM-LR, MPI-ESM-MR and MRI-CGCM3. Then, their outputs were obtained under three scenarios of RCP2.6, RCP4.5 and RCP8.5. According to the IPCC recommendation, the historical period of 1975 to 2005 was used to calibrate GCM models. In order to mitigate the uncertainty in estimating, the changes of climate variables due to the climate change were weighed by the Mean Observed Temperature Precipitation (MOTP) method, developed by Massah Bovani (2006). Then, the performance criteria were calculated. In the MOTP weighting method, AOGCM models are weighted based on the deviation of mean simulated temperature or rainfall in the base period from the average of the observed data. In this study, the precipitation was used to investigate the uncertainty, due to its importance and effect on runoff. The inputs of LARS-WG model were the time series of observational data of temperature and precipitation of the Shiraz station, along with the output of climate models for every month. With the help of this generator, a 30-year time series of temperature and precipitation data was generated for this station. After this stage, it was possible to use the output of climate change models to predict the runoff in Shirin River Basin (Azam Jareh), using the IHACRES rainfall-runoff model. In order to reduce the uncertainty in AOGCM models, weights were calculated to observe the accuracy of the models in estimating the precipitation parameter. Also, the performance criteria were calculated in order to evaluate the performance of the models. The results showed that different GCM models had different accuracy in predicting precipitation. The MPI-ESM-MR and MIROC-ESM-CHEM models with the weight of 0.166 and 0.010 had the highest and lowest accuracy in estimating precipitation, respectively. Comparing the evaluated performance criteria of each model with the observed data of corresponding precipitation values of the same month, it can be concluded that the use of several different models reduced uncertainty and significantly increased the accuracy of climate forecasts. Comparison of the results of climate change forecast in the future period of 2020-2040 with the base period indicated an increase in temperature and a decrease in precipitation. Performance evaluation of IHACRES model showed that the coefficient of determination (R2) for the calibration and validation period were 0.74 and 0.69, respectively. The corresponding Nash-Sutcliffe coefficients were 0.7 and 0.52, respectively. These results indicated the acceptable performance of the model in rainfall-runoff simulation. Based on the simulations performed, the future outlook of mean annual Shirin River (Azam Jareh) runoff in the period of 2020-2040 indicates a decrease in runoff under all three RCP scenarios. The minimum in runoff was due to the RCP2.6 scenario with 682 mm3 (much less than 3000 mm3 of the base period). Also, the results of the average monthly runoff during the period 2020-2040, compared with the base period, showed a decrease of runoff in the most of months (except May, June, July and August). The highest forecasted runoff reduction, under all three scenarios were belong to January, February, March, April, September, November and October. In general, it can be concluded that climate change would reduce the runoff volume of Shirin River (Azam Jareh) during the future period 2020-2040.

Abstract It is inevitable to use optimization methods for multi-objective reservoirs' operation. In this research, after introducing the whale multi-objective optimization algorithm, its performance as optimal operation of the Boostan dam reservoir was evaluated based on the Conflict Resolution Method of Kalai-Smorodinsky. In the present optimization problem, while applying the constraints of reservoir continuity equations, the objective functions were defined as minimization of downstream water demand deficiencies and minimizing reservoir volume for flood control during the operation period. The performance of the proposed algorithm was compared with NSGA-II as one of the common algorithms in this field. Model performance was compared and evaluated based on reliability, reversibility, vulnerability and sustainability indices. To solve the conflict between the goals, the game theory-based method (Kalai-Smorodinsky method) was used to find the optimal solution. The optimization results showed better performance of the whale multi-objective algorithm than NSGA-II, in both objective functions. In terms of optimization time, the multi-objective whale algorithm converges faster than NSGA-II because of the fewer regulatory parameters. The model performance evaluation indices show that whale algorithm reliability is higher (86%) than NSGA-II. Moreover, the results of Shannon entropy method for weighting the indices showed that the model evaluation parameters are more weighted than the objective functions. The results of the Kalai-Smorodinsky method showed that the operation policies of Boostan Dam Reservoir have got a very good agreement with the whale multi-objective algorithm. On the other hand, since the most and the least desirable objective function values estimated by the whale multi-objective optimization algorithm are less than the other one, the performance of the whale multi-objective algorithm can be more appropriately identified.

Abstract Humans need to expend energy to meet their basic food. Excessive fossil energy makes it possible to provide food to the growing population. While, population is increasing, energy resources (especially fossil fuels) are declining, so communities need basic planning for energy management. Agricultural activities are among that energy consuming needs. By consuming energy inputs, the crops are produced. Besides, water is the other key input. Use of fossil fuels in water pumping has environmental impacts on nature, which the type and extent of these effects has particular importance.
Due to the importance of the water role, its required energy in crop production and the environmental effects, this research was conducted regarding Life Cycle Assessment (LCA) for evaluating the potential effect of irrigated wheat in Isfahan province, during the crop year of 2017-2018. To obtain the information needed in this study, questionnaires were designed by interviewing a number of experienced farmers, irrigation experts, and agricultural technicians. Then, the questionnaire was given to wheat farmers in 24 counties of Isfahan province. The selection of farmers who completed the questionnaires was performed using a systematic (regular) random sampling method. Based on questionnaires information, the amount of energy consumed in extraction of water needed for wheat cultivation in 24 counties of Isfahan province was investigated and calculated. In addition, environmental effects of extraction and water transfer on wheat cultivation fields were also estimated. According to the results, the highest and lowest energy ratio of water consumption with amount of 10.73 and 1.4 was obtained in Lenjan county and Aran and Bidgol, respectively. This ratio was obtained about 3.3 for the provincial average. In other words, by consuming of each unit of water energy in the province, 3.3 units of grain and wheat straw energy are produced. One of the reasons that caused diversity in energy ratios in different cities of the province was the difference between wheat yield and water pumping energy. In some counties such as Aran and Bidgol, due to climatic conditions and water and soil quality, wheat yield and consequently its energy extracted were less than other counties. But, in some geographical locations of the province, the water level was significantly lower than the other places, which increased the energy for pumping water. The study of water energy productivity showed that its value varied from 0.10 kg/MJ in Aran and Bidgol counties to 0.79 kg/MJ in Lenjan county. The average of this parameter in the province was 0.24 kg/MJ. According to the results, the group of global warming effect due to water consumption for producing of one ton wheat in Isfahan province varied from 44.87 to 736.9 kg of equivalent carbon dioxide, respectively in Lenjan county and Aran and Bidgol county. Its provincial average was 375.26 kg of carbon dioxide equivalent. The value of acidification potential varied from 0.29 to 4.88 kg of equivalent sulfur dioxide, respectively in Lenjan county and Aran and Bidgol county. Its provincial average was 2.49 kg of equivalent sulfur dioxide. The terrestrial eutrophication potential varied from 0.18 to 2.98 kg of equivalent nitrogen oxides, respectively in Lenjan county and Aran and Bidgol county. The provincial average of the terrestrial eutrophication potential was estimated to be 1.51 kg of equivalent nitrogen oxides. The depletion of fossil resources duo to water consumption varied from 141.94 MJ (Lenjan county) to 2335.39 MJ (Aran and Bidgol counties) and its provincial average was 1189.29 MJ per ton of wheat. The depletion of water resources effect, which represents the water consumed per ton of wheat seed production, varied from 1373.81 m3 (Lenjan county) to 2933.38 m3 (Semirom county) and its provincial average was 1987.12 m3. The lowest and highest Environmental index (Eco-index) of water consumption in wheat was 0.02 (Lenjan county) and 0.33 (Aran and Bidgol county), respectively, with a provincial average of 0.16. There are several ways to increase energy productivity in water consumption.
In conclusion, any action to increase performance or reduce energy consumption will improve productivity. These activates can be divided into two areas: water pumping conditions and wheat production conditions. In the first part, activities such as installation of pumps and motors in accordance with the pumping conditions and repair or replace worn-out parts of the pump and motor can be done. In the second part, modify of the cultivation pattern with consideration of water resources limitations, use of varieties with less water requirement and resistant to drought stress, and finally increase in the efficiency and productivity of water consumption are the important steps to increase wheat yield or replace it with productive crops.

Abstract The most important causes of water shortage in today's world are population growth, reduced rainfall, land use change and urban development. Water is essential for many aspects of economic and social development, agricultural, urban and industrial uses and is an important component for the environment. In other words, water is considered as one of the most valuable natural resources and the most important issue and challenge in this century. Increased water demand due to population growth, development of agricultural and horticultural lands and in general the quantitative and qualitative limitations of harvestable water resources as one of the most important challenges in water resources management and planning, led to the combined use of surface water resources and Groundwater seems to be essential as the two main sources of water supply. Integrated management of surface and groundwater resources is the combined exploitation of two sources in which surface and groundwater resources are used together. The main goal of integrated management is to achieve sustainable development. Therefore, the principles of integrated management are based on the combination of supply management with demand management, which also considers environmental, social and economic aspects. Considering that most of the water needs in our country are met through aquifers, so knowing the status of aquifers can help in proper management of water resources in the region. One of the solutions to deal with the issue of over-extraction from groundwater resources is the use of integrated surface and groundwater management. Due to the decrease in precipitation, especially in recent decades, the reduction of surface and groundwater resources and the uncontrolled abstraction of aquifers and the increase in demand have resulted frome this. In such situations, the need for accurate management of water resources is strongly felt, and the tools of this management and careful planning are the extraction of relationships between factors such as rainfall, groundwater level, consumption, and so on. Marand plain is one of the forbidden plains of East Azerbaijan province, which lacks permanent surface water resources. Therefore, excessive exploitation of groundwater resources has caused a sharp drop in water levels in the region. Therefore, the study of surface and groundwater in this area in order to achieve a proper management approach seemed necessary.
In this research, the consumptions of Marand plain were evaluated by using the simulation model of WEAP and GMS. The calibration and validation of these two models respectively were done based on a ten-year-period of 2002-2011 and a of 3-year period of 2012-2014. Then, different managerial scenarios were considered providing the drinking water in Marand. The scenarios were defined through limitations in using wells, increase the efficiency of irrigation in agriculture section, construct a sewage system, and two combinations of the above mentioned scenarios, in order to reduce the water demand and improve the condition of aquifers. Predictions were made for a 23-year-period according to these scenarios and its effects on the studied water sources. Results indicated that simultaneously utilizing different methods of water management is better than using a single method, which leads to the improvement and revival of aquifers and reduction of water extraction from different sources. The reliability index of providing water in the compound method, for different sections of urban drinking water, rural, agriculture, and industry was calculated at 100, 100, 64.7 and 74.6, respectively. By the compound scenario, the water level would have 16 meter reduction, while the aquifer could be improved with the yearly recharge of 0.29 million square meters and have a relative balance between withdrawals and recharges of the aquifer.

Abstract The quality of groundwater resources has particular importance due to the necessity of utilization and type of consumption. The aquifers adjacent to the volcanoes are affected by these sources exhibiting different behaviors. These aquifers are highly vulnerable and their water quality is affected by sources of volcanic pollutants. In this study, the qualitative status of the Khash aquifer in the south of Taftan volcano has been investigated. Qualitative problems are caused by natural factors and human activities. There are some situations that human activities intensify the natural factors in qualitative problems, such as: the chemical exchange of arsenic and chromium in the aquifer, the invasion of saline water fronts by the sea and saline areas, the qualitative effects of natural events such as volcanoes, changes in the Earth's motion due to earthquakes, etc. Khash Aquifer is located at the down part of Taftan Mountain in Sistan and Baluchestan Province, Iran. The purpose of this study was to identify the contaminant sources of this aquifer. Therefore, in addition to sampling and qualitative analysis, MT3D qualitative simulation model was used. Simulation of qualitative model and regional analysis of groundwater flow in the area revealed that the southern part of the aquifer isis charging by underground nutrient flows from the northern part. Also direct underground feeding from the higher altitudes, with geological formations affected by volcanoes, increases TDS and sulfate concentrations in the southern part of the aquifer.` Groundwater resources are the main source of water supply for the consumptions in this aquifer. The two processes of convection and diffusion in the aquifer were introduced as the main components of qualitative simulation in the model. For the purpose of qualitative simulation of aquifer, the time step was performed as 6 months, from October 2011 to September 2016, including 10 time simulation steps. The qualitative model of aquifer is based on a quantitative model of aquifer and the initial concentration of sulfate and TDS in the aquifer was considered as the basic conditions for qualitative simulation. In order to define the initial conditions using the measured results of sulfate concentration and TDS in October 2011, Craig's internalization method was used. The results of simulations showed that in this section more than 12% of TDS and 30% of sulfate increased. This increase, in addition to the lack of operational management, also indicates the existence of underground currents that have exacerbated the situation of human interference. Investigations showed that the amount of gas in groundwater resources in the northern part of the aquifer was high and this increase also acidified groundwater resources in the region. Also, an examination of the exploitation wells in the northern part showed that the water in these sources has a large amount of gas, and this amount of gas in some places is so high that it has even changed the taste of the water. Evaluation of various studies showed that a geological activity plays an important role in the formation of gas in groundwater resources. Examination of other quality parameters in the groundwater of the region indicated that the more groundwater routes, the higher amount of solutes dissolved in it. Therefore, increasing the TDS concentration is a clear feature of these changes. The results of numerical simulation using MT3D model also confirmed this trend of changes in aquifer. Also, the results of qualitative analysis of pH in the groundwater resources of the region showed that, most of the wells in the aquifer were acidic; only the well of Dasht-e Robat village had a high alkalinity. Another source of acidification could be the surface oxidation of H2S gas, which exacerbates rock dissolution. These types of water have low chloride but high sulfate. The average concentration of sulfate in the aquifer highly fluctuated.  Nikabad village (at the beginning of the aquifer and down of the Mehran power supply dam) has the most concentration of sulfate due to its proximity to the Taftan Mountain and the dissolution of sulfur in surface waters entering the plain. This fact is the opposite of the assumption  that the southern wells have the more the amount of sulfate. So that the village of Kalki at the end of the aquifer has the highest amount of sulfate 1660 mg/lit. Based on the results obtained from the aquifer quality modeling, the simulation of water quality status for the TDS and sulfate parameters for the forward 3-year period was analyzed It indicated that there would be 12% and 30% increase respectively in TDS and sulfate concentration, in southern part of aquifer. Hence, appropriate management should be applied to address the water acidity. 

Abstract The excessive groundwater pumping and different hydraulic and geotechnical soil properties due to the stratified soil around pumping wells are of the most important factors on the land subsidence. Some consequences of land subsidence include: the formation of cracks on the ground surface, destruction of buildings, damage to water conveyance pipelines embedded in the ground, change in the longitudinal river steepness and vulnerability of residential areas to flood events due to lower soil permeability caused by the land subsidence. Because of the widely use of GIS to the evaluation of earth properties, many researches have been conducted so far on the application of GIS to land subsidence analysis. In this regard, a number of GIS-based researches focus on the application of data derived from In-SAR radar to monitor the land subsidence without any geotechnical analysis. Due to the necessity of geotechnical analyses to more accurately approximate the land subsidence, the researchers proposed a method based on the influence function in order to relate the variation of phreatic groundwater surface around the pumping wells to the deformation of ground surface causing the land subsidence. Despite the incorporation of soil stratification effect, the inattention to variations of phreatic surface in variable pumping conditions from multiple wells and the mutual effects of wells on each other is accounted as a weakness of the proposed method which is addressed in the present study. In the present research, a practical computer program (so-called CALS-SVD) was developed which initially imports the physical and hydraulic properties of an aquifer from GIS including the longitude and latitude of wells, the specific storage coefficient of the soil, hydraulic conductivity, initial void ratio of the soil, soil compression index, the wet and saturated specific weights of the soil. Then it applies a new method integrating Influence Function with equations of varied pumping-induced influence radius of groundwater surface to estimate the subsidence (from multiple wells in a given time). Finally, the results of computations are added as new information layers to the imported GIS file. The developed computer model was applied to a case study in west of Guilan province, located in the road connecting Saravan to Fouman. The applied approach in the studied area was to divide it into two regions. Then, 6 scenarios were considered in terms of reported pumping rates (ranging 30 to 120 m³/d). The maximum reported pumping rate in the region (120 m³/d) and the half and quarter of the maximum pumping discharge were applied to the wells located in two mentioned regions in order to model the land subsidence in the entire studied area. Taking into account the overlap of pumping wells, one of the wells located in the middle of others was selected as the origin and the effect of all the wells on each other were determined based on the relative distance derived from their longitudes and latitudes. The scenario A120B120 incorporating the maximum pumping discharge at the both divisions of the studied area used to validate the model. Validation of the obtained results with the field surveys shows an admissible performance of the presented software. Additionally, the results showed that the pumping-induced subsidence up to 30 cm around the wells leads to the expansion of subsidence area in the region. But a greater subsidence depth has negligible influence on the subsidence area, and it will be limited to 70 percent of the total surface area of the region. Meanwhile, the higher the pumping rate, the greater will be the influence radius. But the rate of increase in influence radius decreases for higher pumping values. Thus, the average influence function will be limited to 105 meter at the studied area. According to the results, there is a linear relationship with an admissible correlation coefficient between the average groundwater pumping rate (in a 10 year period) and the maximum subsidence depth. Moreover, the maximum subsidence depth is highly affected by the stratification of the soil. Whereas, the subsidence increase rate with pumping is mostly affected by the percentage of increase in pumping. Finally, the application of presented subsidence model in the studied regions indicates lower magnitude and rate of subsidence in a 10-year period in comparison with the results obtained from Damghan in a 5-year period. 

Abstract Evaluation of irrigating systems is defined as the analysis of the system based on measurement in real field conditions, during the system operation. The evaluation of the system deals with the fact that to what extent the designed system has reached the design goals. Many researchers have reported and evaluated the problems of drip irrigation systems in recent years. A research that evaluated drip irrigation systems in southwestern Okra, Nigeria, resulted that the volume of water given to the products was more than the water requirement of the plants and the efficiency of the system was %68.5. The other study examined various uniformity indices in drip irrigation systems in bamboo. The researchers concluded that due to the high sensitivity of the bamboo plant to the amount of received water and the distribution of moisture around it, the drip irrigation droplets with the flow rate of 4 lit/hr were more appropriate in compared with the 8 lit/hr. It could well meet the water needs of that plant. The purpose of this study is to evaluate the status of drip irrigation systems implemented in Dashtestan city to identify their strengths and weaknesses and provide suggested solutions to eliminate defects in the systems and improve their efficiency. In this study, five drip irrigation systems in Dashtestan city were studied and evaluated. To evaluate drip irrigation systems in selected orchards, the proposed methods and formulas were used based on SCS standard and Merriam and Keller methods. Measurement of field evaluation factors included three steps: 1) Measurement of soil factors, 2) Determination the characteristics of the garden under study, 3) Measurement of hydraulic characteristics of irrigation system. A sample manifold was selected from each system, and the evaluations were performed on four laterals from the beginning, one third, two thirds, and end of the lateral. At each selected manifold, eight pressures were obtained at the beginning and end of the lateral tube, with 32 volumes of water at 16 trees. The average volumes of emitters and dispersion uniformity were calculated from the obtained volumes. The minimum input pressure of the sample manifold and the operating manifolds were also measured to determine the Efficiency Reduction Factor (ERF) and the DCF. After collecting data from field measurements using SCS and Merriam and Keller methods, evaluation factors such as water emission uniformity (EU), real low quadrant use efficiency (AELQ) and potential yield, the lower quadrant (PELQ) was calculated. The results showed that water distribution uniformity varied from 77.98% in M5 to 92.12% in M3. Low quadrant potential (PELQ) efficiency with 82.91 and 70.18% and true low quadrant use efficiency (AELQ) with values of 92.12 and 77.98% were obtained in M3 and M5 systems, respectively. The results indicated status of good to moderate in the systems. It was observed that when the farmer turned on the systems of M1, M2, and M5, they paid no attention to the water leaking out of the drippers, and did not remove them in cases of clogs or leaks from the connections. In the M5 system, due to the three-year of the filtration system, a highest pressure drop (3.9 m) was observed. In general, the main problems of the systems in this study were: the low wetted area due to the inappropriate design and number of drops, the lack of proper placement of loop rings, the lack of uniformity of pressure distribution in the system, inappropriate wetted depth, the lack of uniformity of distribution of water, and the low knowledge and skill of the user. Due to the traditional irrigation system in Bushehr province and the high water demand of palms, about 70% of the water consumed in the agricultural sector was used for palm consumption. Therefore, it is necessary to pay attention to the improvement of palm irrigation methods in this province. According to assessment and measurements made in this study, drip irrigation systems would perform better if they were designed well to meet the plant's water requirements in a desirable way. The drip irrigation systems can create significant savings over traditional irrigation methods. Therefore, it is recommended to use more of these types of systems in this province. However, in some areas of the province, which have a source of salt water, some of drip irrigation systems have been clogged and out of use that require system improvement and operation training for farmers.

Abstract The arable land in Iran is about 11 million hectares, and maize production is the second largest after wheat production. Agricultural studies in Iran lands reveal that the water use efficiency of irrigation is between 22.5% and 85.5% with an average of 56%. Drip irrigation is one of the best methods that by applying appropriate management can be used for agriculture in high salinity soils, with saline irrigating water and dry conditions, especially for maize crops. Sprinkler irrigation system has a positive effect on improving irrigation efficiency in Iran, but the main problem of this system is the water loss related to evaporation and wind. Usually, drip irrigation plan is implemented in combination with sprinkler or low-pressure irrigation plan, so that it is possible to change the irrigation network and make an optimal use of the system according to the needs of the cultivation pattern. In the most previous studies, drip irrigation tape was generally used, depending on the type of crop and the growing conditions. Also, limited studies have been conducted on the comparison of irrigation tape types, hence comprehensive studies are needed. Also, study on the interactions of different types of tapes and irrigation levels is needed. The aim of this study was to evaluate the performance and yield components of forage maize under moisture stress. A pilot project was conducted in form of factorial experiment of randomized complete blocks, during one year in Isfahan province. There were 6 treatments consist of emitter tape systems of 15, 20, and 30 cm, and drip tape of 10, 20, and 30 cm with distance of 0.7 m.  The treatments of irrigation included 5 levels of 100, 90, 80, 70 and 60% of soil moisture depletion, with 3 replications. The cultivated maize cultivar was Single Cross 704, which was cultivated at 0.7 m intervals. For each treatment repetition of three rows of the same irrigation strip with the length of 50 m was performed. The crops were harvested from the middle row. During the growing season, irrigation was carried out for 22 times based on the measurement of moisture in the root zone and the supply of moisture deficiency to the level of crop capacity in terms of programmed water shortage. For each treatment-repetition, amounts of total product weight, total weight of maize, average plant height, average height of maize, product productivity index and maize productivity index per hectare were calculated at the end of the cultivation season after sampling. The results showed that the main and interaction effects of irrigation tape type and irrigation rate on yield components were significant at 1% probability level. Based on the performance indicators, the best treatment was the emitter tape strip with the 20 cm nozzle-distance, the total crop yield and maize yield of 70112 and 14593 kg/ha, respectively. According to the product performance index, the emitter tape with the diameter of 30 cm and the drip-tape of 30 cm, were the weakest treatments in terms of maize's performance. Wetting widths in heavy-textured soils are wider than in the light-textured soils. Despite the relatively heavy texture in this study, the 30-cm distance between the nozzles in the irrigation strip did not provide adequate overlap in the development of moisture within the plant root zone. Therefore, the irrigation tape with the nozzle distance of 30 cm is not recommended for the cultivation of forage maize in similar conditions of the present field. In terms of irrigation levels, the best result obtained in the treatment of 100% depletion of the moisture capacity of the root area with crop yield and maize yield was 66.5 tons per hectare and 11.3 tons per hectare, respectively. According to the two indicators of plant and maize height, the drip-tape irrigation strip next to the seam with the nozzle distance of 20 cm (with plant and maize height of 19.15 and 19.4 cm, respectively) as well as the 15-cm emitter tape were in the top group. The weakest treatment according to these two indicators was the 30-cm drip tape and then the 30-cm emitter tape treatment. A comparison based on irrigation levels showed that the treatment supply of 100% depletion of moisture capacity of root zone was the superior treatment with the plant and maize height of 179.3 and 15.3 cm, respectively. Also, in terms of maize's height, there is no significant difference between the treatments of 80%, 90% and 100. In terms of water efficiency indicators, the 20-cm drip tape was the best option with crop and crop water productivity of 13.4 and 2.8 kg/m³, respectively. The highest water productivity for the total product and maize occurred in the treatment of 100% and the lowest in the treatment of 60%. Based on the interaction of irrigation tape types and irrigation levels, the superior treatments was that in which the drip tape by 20 cm was applied, 100% of soil moisture was provided, forage yield and water productivity of 81279 kg / ha and 14.2 kg / m3 were obtained, respectively.