yousef hassanzadeh

This study investigates the hydraulic characteristics of flow, including flow velocity, pressure, and cavitation index, at various inflow rates using FLOW-3D. The results indicate that as flow passes over the ogee spillway, the flow velocity increases, and this upward trend continues gradually along the chute section. Due to the steep slope of the chute section, the maximum flow velocity occurs here and is eventually dissipated upon entering the stilling basin, where dynamic energy is absorbed. Longitudinal pressure distribution along the spillway reveals a reduction in pressure from upstream to downstream, with the most significant decrease occurring at the downstream end of the chute. The maximum flow velocities at inflow rates of 300 (minimum design discharge), 830 (10,000-year flood discharge), and 2270 m³/s (maximum probable flood, P.M.F.) were recorded as 34.25, 41.80, and 44.90 m/s, respectively, at the downstream end of the chute. Additionally, the minimum flow pressures for these discharge rates were 1.23, 1.52, and -5.9 kPa, respectively. Examination of the cavitation index along the channel bed indicated that cavitation occurs in the chute section under all inflow conditions. However, the cavitation index assessment on the sidewalls showed that the ogee, chute, and initial sections of the chute sidewalls remain unaffected by cavitation. Conversely, the cavitation index in the downstream chute sections decreases below the critical threshold, indicating potential cavitation risk in these regions. Therefore, to prevent the occurrence of the destructive cavitation phenomenon, the implement of flow aeration method from the floor and sidewalls of the channel is recommended.

The key to social and economic development is water, an essential natural resource. Worldwide, many areas are experiencing water supply and demand mismatches or are under extreme stress due to water shortages. Water resources have been mismanaged or limited due to an increase in demand and limitations in available water supply (Banadkooki et al., 2019). Rainfall and runoff are considered to be the main components of the hydrological cycle. In order to capture the dynamic relationship between rainfall and runoff, engineers need to develop an accurate model (Tikhamarine et al., 2022). Rainfall-runoff modeling is one of the methods of estimating runoff and a suitable tool for studying hydrological processes, evaluating water resources and watershed management (Abrahart and See, 2000). But the complexity and non-linear nature of the rainfall-runoff process and the unknown effect of the factors on each other and finally on the outflow of the basin make modeling more difficult (Moriasi et al., 2007). Therefore, it is necessary to use methods that, in addition to dynamism, have the ability to develop, have a conceptual and user-friendly structure (Shi et al., 2012). The role and importance of the mentioned process in water resources studies has caused this process to be noticed by experts (Guven, 2009). Therefore, several methods such as artificial neural networks, fuzzy and neuro-fuzzy systems, wavelet analysis, genetic algorithm, genetic programming and stochastic differential equations have been developed to model the rainfall-runoff process (Yaseen et al., 2016; Zhang et al., 2019). The development of rainfall-runoff models using different AI models has been conducted several times in the past two decades, but these models still have several shortcomings. These drawbacks are usually related to overfitting, difficulty in initializing the internal parameters related to these models and proposing the proper input-output architecture of the model (Ahmed et al., 2019).

Ziwiye, as one of the key sites for Iran’s North West Iron Age (Median kingdom), has many masterpieces kept in different museums and a long list of publications. The main part of this list consists of monographs that are written based on one or more limited objects from an out of context collection. There are few articles that comprehensively include the findings “attributed Ziwiye” and “came from excavation”. However, many articles have been published about Zavieh’s findings, but parts of this collection still remain unknown and do not receive enough attention. The corpus of bone arrowheads is one of them, some of which were found during archaeological excavations while others came to museums from antiquities dealers. These include: the Metropolitan Museum of Art in New York, Musée du Louvre in Paris, the National Museum of Iran in Tehran, and the Sanandaj Archaeological Museum. This article aims to introduce and categorize 51 bone arrowheads. Some of these were registered as ivories, but our research concluded that all of these were made of bone. In few instances, the production manner prevented the proper identification of bone versus ivory. Another examined point in this research is whether such arrowheads were produced for actual warfare or for prestige and symbolic use in ceremonial events considering their bone material. The examined samples from other sites show that bone can be hard enough to penetrate game and human body even with light protection such as archery. Bone for making arrowheads was used for hunting big games and some tribes still use them.

Although a dam’s structure has an important role in suppressing floods and providing water for activities such as agriculture, human consumption, industrial use, electricity generation and pisciculture, its break has an immense damage and loss of life when it occurs. In order to reduce the damaging effects of the dam break on the downstream places, it is necessary to provide the flood hazard map.There are few studies on applying HEC-RAS two-dimensional model in the field of dam break analysis. For example, Hassanzadeh et al. (2019b) computed the output breach hydrograph of the Alavian dam by the BREACH model under the overtopping scenario. Also, the breach hydrograph was routed through the downstream of the river by using HEC-RAS two-dimensional model. Finally, the ArcGIS software was utilized to prepare the flood mapping. The results of their study illustrated that the Alavian dam is breached with the time of failure of 46 min and the peak discharge of about 66000 m3 s-1. Furthermore, according to the flood hazard map, most of the downstream inundation zones due to Alavian failure dam have been considered as the high hazard area.

Two-dimensional (2D) numerical simulation proved to be an important tool for understanding flood events. The HEC-RAS model is one of the most popular hydraulic models. In 2016 a new version of HEC-RAS (HEC-RAS-v5) was released including 2D capabilities. HEC-RAS software supports special capability to correct waterway and computing necessary ground-related operations. The capabilities of HEC-RAS are: 1) Developing a 2D unsteady flow model; 2) Modeling the 2D shallow water equations or the 2D diffusion wave equations; 3) Solving implicit finite volume algorithm; 4) Developing a terrain model and geospatial layers. The HEC-RAS software also enjoys connect-ability to ArcGIS software via an adaptor called HEC-GeoRAS to perform pre- and post-processing in geographical information system (GIS).The threat to personal safety and to gross structural damage caused by floods depends largely upon the speed and depth of floodwaters. The greater these factors become, the greater the danger to people and property. The depth-velocity hazard classification diagram considered in this study is based on the Garcia and Lopez (2005), in which hazard categories are broken down into high, medium and low hazard for each hydraulic category. These can be defined as: 1) High hazard: possible danger to personal safety; evacuation by trucks difficult; able-bodied adults would have difficulty in wading to safety, potential significant structural damage to buildings; 2) Low hazard: should it be necessary, truck can evacuate people and their possessions; able-bodied adults would have little difficulty in wading to safety; 3) Medium hazard: In the transition zone highlight by the median color, the degree of hazard is dependent on site conditions and the nature of the proposed development.

In this research, the dam break problem has been presented from the viewpoints of importance, mechanism, spatial and temporal analyses as well as governing mathematical equations. For this purpose, the output hydrographs of the Bafrajard dam site have been computed by breach model under a fictitious dam break scenario (overtopping) as the first step. In the next step, the output hydrographs have been routed through the downstream river by using HEC-RAS model. Then water levels and wave front arrival times have been computed at all cross sections. Finally, the obtained results have been imposed to Geographic Information Systems in order to obtain the presentation of the results to develop floodplain maps.

The results of the present study demonstrated that the Bafrajard dam is breached with the time of failure of 80 min after the upstream erosion and the peak discharge of about 4000 m3 s-1. Also, Khanghah-e Bafrajard village, Aznav tourist area and Khalkhal city are affected by floods with inundation percentages of about 35, 10 and 20%, respectively. Furthermore, the wave front arrival time at the mentioned areas is about 10, 30 and 40 minutes, respectively, so there will be very short time available for various emergency actions.

The use of gate-sill combinations in recent years has been one of the new methods in increasing the hydraulic performance of gates, including the discharge coefficient (Cd). The present research aims to investigate the Cd of the gate with a sill in different dimensions in width and various positions relative to the gate using support vector machine (SVM) models, the K nearest neighbor (KNN) algorithm, and the artificial neural network (ANN) method using Statistica software. Out of 345 experimental data, 70% (241) were used for training and 30% (104) for testing. The best results are obtained when all dimensionless parameters (Atotal/B2, H0/B, Z/B, ε/B, and X/B) are used. The results of different kernels showed that RBF kernel has better results in predicting Cd compared to Polynomial, Linear, and Sigmoid kernels. The results of the statistical indexes of R, KGE, RMSE, and Mean RE% for the RBF kernel in the test phase are 0.955, 0.90, 0.0192 and 1.82%, respectively. In the KNN model, Manhattan distance measure has favorable results compared to other Euclidean, Euclidean Squared, and Chebychev criteria. The results showed that the ANN method has the best performance compared to SVM and KNN models with values of 0.984, 0.976, 0.0098, and 1.15%, respectively.

Streamflow prediction is a challenging and critical task for water resource management. Streamflow prediction is one of the essential steps for reliable and robust water resources planning and management. On the other hand, streamflow prediction plays a crucial role in water resources systems planning and mitigating hydrological extremes such as floods and droughts. Since a variety of uncertainties exist in streamflow prediction, it is necessary to enhance our efforts to robustly address uncertainties and their interactions for improving the reliability of streamflow prediction. It is highly vital for hydropower operation, agricultural planning, and flood control. Physical process-based models are developed based on the understanding of the runoff generation processes, transport in channels, and mathematical formulations or parameterization of these physical processes. Data-driven models have the advantages of low demand for model input and ease of use. Due to the influence of various factors, including climate change, human activities, and socio-economic development, the hydrological time series leads to its complicated stochastic characteristics. Statistical models are the typical examples of this category and have been widely used in streamflow predictions over different regions. Different statistical models, machine learning methods are effective in describing the nonlinear characteristics of the observations and offer an alternative approach for streamflow prediction. Over the last two decades, a variety of machine learning techniques, including the artificial neural network (ANN) and the support vector machine (SVM), have been extensively applied in water resource management and hydrological prediction.

In this research, from the data of precipitation (Pt), precipitation with a delay of one day (Pt-1) until precipitation with a delay of three days (Pt-3) and discharge with a delay of one day (Qt-1) until discharge with a delay of 3 days (Qt- 3) are used as input variables and discharge (Qt) is used as output variable to predict the flow of Kurkursar river in Nowshahr. The Kurkursar river basin in the north of Iran is considered a sub-basin of the North Sea, its area is 75.495 km2, the average height of the basin is about 860 m, and the overall average slope is about 80.21%. This basin has an oblique shape and is limited to the Caspian Sea from the north, the Meshlak river and part of the Chalus watershed from the south, and the Chalus watershed from the west. Various geomorphological forms such as floodplains, alluvial cones, and sediment dams have been identified in the river basin area. The time series is daily and 70% and 30% of the data are respectively used for the training and test processes. The models used in this research include three individual models (random forest model - artificial neural network and regression support vector machine) and three hybrid models including bagging tree model - random forest (BA-RF), neural network - creative rifleman (ANN-AIG) and Support Vector Machine Regression-Crow Search (SVR-CSA) was used. In order to evaluate the model, the Mean square error (MAE), root mean squared error (RMSE), Nash–Sutcliffe model efficiency coefficient (NSE), and the PSR were used. Pearson's correlation coefficient (PCC) is used for the relationship between input and output variables. Therefore, we calculate the correlation coefficients between input and output variables, then we evaluate the composition of the input model based on different scenarios. The model combination that has the highest correlation is selected as the selected model. Then, the internal coefficients of each model are optimized with the help of meta-heuristic optimization algorithms. Therefore, the prediction results and observational data of the model are compared with each other. Finally, time series graphs, data dispersion, and box plots will be drawn and we will compare different evaluation indicators quantitatively and qualitatively. Finally, we compare the results of all models with each other and choose the model that has the best result as the best model. In the final step, we will compare the accuracy increase of the hybrid model (error reduction) with the standalone model to determine the error reduction percentage.

The Koukursar Nowshahr river flow was predicted using seven model with combinations of predictive variables such as R (t), Q (t-1), Q (t-2), R (t-1), Q (t -3), R (t-2) and R (t-3) as input variables and flow rate (Qt) as output variable. The results show that the precipitation variable (Rt) with a value of 0.563 has the highest correlation with the output variable, followed by Q (t-1) with 0.463, Q (t-2) with 0.297, R (t-1) with 0.281, Q (t-3) with 0.251, R (t-2) with 0.124, and R (t-3) with 0.072. Variable R(t) with 0.563 has the highest correlation, and variable R(t-3) with 0.072 has the lowest correlation with the output variable. Based on this, the relationship between the input and output variables was shown based on the correlation coefficient using the radar chart. In this regard, in this research, three individual models and three hybrid models were used to predict the river flow. Among the different scenarios and combinations of the input model, model 7 was used as the final model for forecasting. The evaluation results show that the RF model in the training phase has R2= 0. 957 and in the test, a phase has R2=0.717. The RF model has the highest correlation coefficient among all research models in the training phase. Also, in the test phase, it has the third rank among all models. ANN-AIG model improved the error of the single model by 32.94 %, the single SVR-CSA model by 23.17%, and the BA-RF model by 17.74%.

The qualitative results of the models show that all the models performed very well in predicting the model. Among the research models, the ANN-AIG model has performed best in forecasting.

Accurate prediction of dam breach parameters in embankment dams is an essential step in the risk management plan. Overtopping and piping are the leading causes of embankment failure in the world. The failure of this type of dam is typically proposed by hydrological and hydraulic computational models of the dam (Wahl, 1998). The relationships for assessing the breach and flow characteristics are generally obtained by artificial intelligence and regression analysis from case studies of historical dam failure. These models relate the input parameters such as the dam height (Hw) and the flow volume through the breach (Vw) to the observed breach parameters resulting from the actual failures. Several relationships have been proposed to calculate Qp as a function of Hw and Vw (De Lorenzo & Macchione, 2014; Hagen, 1982; Kirkpatrick, 1977; Singh & Snorrason, 1984; Hakimzadeh et al., 2014). Downstream sediment transport studies show that breach geometry directly affects the output hydrograph. Investigations on historical records for Qp determination show that Hw and Vw could provide more accurate results than El and Ew. Moreover, the combination of these parameters significantly increases computational accuracy (Thornton et al., 2011; Wang et al., 2018). Several laboratory and field studies have been performed to investigate the hydraulic properties of the breach and the output hydrograph in overtopping failure cases (Dhiman & Patra, 2017; Sadeghi et al., 2020; Vaskinn et al., 2004). Determination of the average breach width (Bave) is an essential factor in determining progressive erosion (Von Thun & Gillette, 1990; Froehlich, 1995) as well as the height of breach (Hb). The range of variation in Bave as a function of the dam height (Hd) is an important issue in the breach lateral evolution process (Johnson & Illes, 1976; Singh & Snorrason, 1984).

In this research, the relationships of the discharge coefficient of the sharp-crested U shape plan form labyrinth weirs (one cycle) have been investigated experimentally and numerically. Also, from 3 groups of weirs with heights of 10, 12.5, and 15 cm and at each height, the length of different arches to the values of 40.82, 45 and 48.10 cm have been tested. The main purpose of the present study is to determine the overflow discharge from the weir by providing relationships for the discharge coefficient experimentally. Dimensional analysis was used by 𝜋 Buckingham method to extract the relationship. Three-dimensional simulation of weirs was performed numerically with equations governing the finite volume method using FLOW-3D software, then compared with laboratory results. The results of the present study show that the proposed relationship can predict discharge values with very high accuracy and an error of 4.79% in the ratio of the head-to-height weir of 0.1 to 1.2. As the length of the weirs arch increases, the flow interference increases, and the discharge efficiency decreases. Although with increasing the length of the weirs, the length of the crest increases, the weirs efficiency decreases, the maximum throughput efficiency decreases in this case, It is at 7.01%. With constant arc length and increase in weirs height, it was observed that the throughput efficiency decreases significantly, which shows a maximum volume of flow through the weirs of 4.82%.

Determination of the breach parameters and resulting hydrograph of the embankment dam failure due to overtopping and piping erosion has great importance because of the significant injuries and environmental impacts. In this research, by investigations on the erosion mechanisms, the affecting processes on the embankment dam failure are examined, and empirical relationships are presented to determine the peak outflow discharge (Qp), time, and breach characteristics in the overtopping and piping failure cases. Physical models with different heights and technical specifications were constructed and failed in the experimental flume to study the breach expansion rates. In the other part of the research, new empirical relations have been developed to predict the eroded volume (Ver) based on the breach characteristics and the contribution of various resources including historical, experimental, and hypothetical failures of the real embankments. The BREACH mathematical model has been used to obtain the failure parameters related to the hypothetical breach of the recent dams. According to observations, the failure time (tf) is highly dependent on hydraulic and breach characteristics. Therefore, the tf is considered as a function of these characteristics in the proposed formulas. Based on the performance indices, the values of the determination coefficient (R^2) for the newly proposed Qp relations are equal to 0.94 and 0.91, respectively, in the overtopping and piping failures. This coefficient for the development of the Ver relationship is equal to 0.98, and for the development of tf equations are equal to 0.85 and 0.87, respectively. Since the outflow hydrograph of a breached embankment dam is largely depended on the geometry and evolution time of the breach, the failure hydrographs of real embankments are simulated using a combination of regression analysis and evolutionary algorithms as a case study.

Quantifying the uncertainties of the parameters of hydrological models are the role of great importance in water resource management and is a challenge that due to the large number of parameters and lack of proper physical understanding of them, these models face problems in the calibration stage. Considering the importance of water resources in Iran and the need to investigate uncertainty in order to achieve reliable results, the purpose of this study is to investigate, identify and quantify parameters uncertainty of Soil and Water Assessment Tool (SWAT) and their performance to predict watershed runoff. The Kashfrood river is a semi-arid large-scale basin in northeastern Iran using a Monte Carlo chain-based Markov chain simulation method called the Differential Evolution Adaptive Metropolis algorithm (DREAM-ZS).

With the purpose of assess the uncetainty in this study only 20 out of 29 available parameters were selected and evaluated based on Regional Sensitivity Analysis (RSA) as sensitive parameters. In order to optimize the model and quantify the parameters uncertainty, scenarios S1 (first scenario) and S2 (second scenario), which belong to the DREAM-ZS algorithm, have been defined. The prior parameter ranges of the S1 scenario were determined using the final calibration of parameter ranges in SWAT-Calibration and Uncertainty Program (SWAT-CUP) software and Sequential Uncertainty Fitting version 2 (SUFI 2) algorithm, and the prior ranges of the S2 scenario were determined using a compromising approach between the prior ranges of the SWAT-CUP and posterior ranges from S1 scenario. In this study, the parameters, uncertainties and statistical analysis have to be computed via an appropriate likelihood function. Therefore, the Differential Evolution Adaptive Metropolis (DREAM-ZS) combined with the standard least squares (SLS) as a simple formal likelihood function. Also, to evaluate the performance of the model uncertainty in the two mentioned scenarios, evaluation criteria including P-factor, d-factor, Nash–Sutcliffe (NS), Total Uncertainty Index (TUI) and Average Deviation Amplitude (ADA) were used.

P-factor, d-factor, Nash–Sutcliffe (NS), Total Uncertainty Index (TUI) and Average Deviation Amplitude (ADA) showed that the S2 scenario has a better performance than scenario S1 in reducing forecast uncertainties. According to S1 simulation, the NS coefficient ranged from 0.54 to 0.72, while in S2 simulation, it ranged from 0.63 to 0.78. The TUI for total uncertainty was in a range of 0.2–0.6 and 0.22–0.66 for S1 and S2 scenarios, respectively. The S1 and S2 simulations led to the TUI of 0.63–0.94 and 0.74–1.22 for parameter uncertainty, respectively. Finally, ADA index for total uncertainty was 0.098 and 0.445 for S1 and S2 scenarios, while in accordance to S1 and S2 simulations, the ADA index for parameter uncertainty was 0.098 and 0.451, respectively.

The DREAM-ZS algorithm improved the calibration efficiency of the model and led to the presentation of more real values of runoff simulation parameters by the SWAT model in the Kashafrood River Basin.

weirs are one of the hydraulic and very vital structures from various economic, environmental, safety and security aspects. In addition to passing and flow measurement, they are the controlling structures in the floods. The main purpose of the present research was to predict the discharge coefficient to method of intelligent support vector machine using experimental data as well as analysis of the hydraulic performance of weirs. The geometric variables of the weirs were used 10, 12.5, and 15 cm in height, the length of different archs were 40.82, 45, and 48.10 cm. To analysis the performance, the dimensional analysis was used by the 𝜋 Bakingham method, then by intelligent method, considering different models, the effect of different parameters in determining the discharge coefficient were investigated. As the length of the weirs arch increases, the discharge efficiency decreases, and as the length of the weirs arch increases, the crest length increases. The results of sensitivity analysis also showed that by removing the Ht/P parameter, the model error rate increases up to 14% for training data series and up to 20% for test data series, and this parameter is the most effective variable in estimating discharge coefficient in in U-shaped labyrinth weirs.

Bridges are known as one of the most important communicational hydraulic structures. This is particularly so important in bridge piers exposed to river currents.The flow contact with bridge piers causes erosion around them and would result in damage. Therefore, controlling the erosion around the piers is one of the most important objects in the bridge safety. Many different experimental models have been prepared so far to investigate the flow pattern and local scour around this structure. Regardless of the cost and time of the experiments, problems resulting from changes in scale are also available. Nowadays, the Hydrodynamic behavior of the fluid is more extensively investigated by using the more efficient codes of computational fluid dynamic (CFD). The Flow3D software is used for this regard. This study focuses on the simulation of flow around the different bridge piers and studied the flow pattern and bed erosion around them. In this regard, the assumption of incompressible fluid is used and the sharp free surface is modeled by Volume of Fluid (VOF). Considering the sensitivity of numerical models to the number of cells in the computational domain, verifying the number of cells has been done by comparing the velocity profiles. Three different turbulence models also are investigated, and the free surface profiles, flow pattern around the pier and the Strouhal number are compared. Finally, the flow simulation is done by LES turbulence model. For investigation the two key factors causing local scouring, flow separation and downward flow in upstream of the pier, th1 10 models is selected. The countermeasures that considered in this regard include berm, cross-section and middle slot. The results show that the effect of flow separation control in reducing the bed erosion is much more than controlling the downward flow. Also the results revealed that in most cases using one countermeasure may be acts more better than situations different countermeasures was applied. In using lenticular cross-section, the scouring depth weas decreased up to 58% and with using the combined round-nosed rectangular cross-section, berm, and slot, the scouring depth showed decreasing up to 50%. Also, it was concluded that controlling the flow separation from the pier in boundary layer and the vortex shedding affect the bed erosion much more than the downward flow in pier upstream.

The estimation of hydraulic conductivity is one of the most important part of hydrogeological studies which is important in groundwater management. But due to practical, time or cost constraints, direct measurement is difficult. Hence, the using artificial intelligence models with low cost and high performance can be an appropriate alternative for this purpose. Since input data and different training techniques in these models are the most important source of uncertainty, the effect of various sources of uncertainty in output should be considered. In this research a Bayesian Model Averaging (BMA) are developed which includes the model combination of artificial neural network, fuzzy logic and neuro-fuzzy to estimate hydraulic conductivity and uncertainty analysis. In the BMA model, the weight of the models is determined by the Bayesian information criterion (BIC), and the within-model variance, steam from the uncertainty of input data and the between-model variance steam from uncertainty associated with the nature of the artificial intelligence model are calculated. In this study, the developed method has been applied to estimate the hydraulic conductivity in the Urmia aquifer. The results show that although the determination coefficient of BMA is not higher than the determination coefficient of the best model, the output of the BMA is the result of assigning weights that take into account the uncertainty between the models and the input data. Also, the effect of groundwater level variation on estimated hydraulic conductivity from pumpage test up to 2015 was evaluated and the result indicated an insignificant changes in hydraulic conductivity.

Utilizing adjacent piers is one of the cost reduction factors in bridge construction. The impact of turbulent flow around piers on each other, piers distance and the amount of scouring in the adjacent piers are of great importance. In this research, it is tried to present a convenient and efficient combination of adjacent piers in order to reduce the amount of scour by analyzing the placement of these piers in two different shapes and various distances from each other and its impact on the amount of local scouring and the bed erosion pattern. Numerical simulation is done by FLOW3D software. Designed models for two cylindrical and combined shapes of piers in two specific placements, side by side and tandem, and in 6 different distance between the two piers for each state, totally 26 simulation models were simulated and investigated. It is found that the scouring depth increases significantly by decreasing distance between piers which creates a wider obstacle against the flow and water jet between the piers. The flow depth is decreased by increasing this distance and the adjacent piers have no impact on the amount and pattern of scouring in S=4D and higher distances away from each other and the most suitable distance was obtained at S=2.75D. In the tandem cases, it was found that the piers distance does not have any impact on the amount of scouring at the upstream and just the middle part experiences quantitative changes in the bed level; this impact is low by decreasing the distance and obvious by increasing the distance. All the mentioned items are correct in the combined pier, but the amount of scouring shows reduction.

Groundwater plays an important role in the sustainable development of human societies. The rapid growth of population, low level effectiveness, and performance of irrigation in agriculture sector have led to increase in demand for water resources in Iran. Therefore, the regional management of water extraction and the optimal usage of available water resources are highly important. Considering the urgent and intense need for groundwater resources, we used Shannon’s entropy and frequency ratio models to identify the groundwater resources of Sero Plain for agricultural and drinking purposes as well as to detect the factors that affect occurrence of groundwater and zoning.

Climatic paleontology evidences that climate change has always been present throughout the history of the planet, but the climatic changes of the last century have two distinct features, as compared with past climatic changes. First, human activities play a greater role in the nature of the current climate change. Second, the speed of recent climatic changes is greater, so that, a lot of changes will be occurring in the Earth's atmosphere during a short term (Telmer et al. 2004). Nowadays, global warming has significant effects on precipitation and runoff yield and water resources due to the increased concentration of greenhouse gases (Pervez and Henebry 2015). The average of climatic variables, especially the components of temperature, precipitation and runoff in the annual or seasonal scale, play a predominant role in the hydrological cycle and usually used as an indicator for assessing the climate change on the available water resources of Iran now and especially in the future (Afshar et al. 2017). A number of studies have been done to investigate the impact of climate change on the hydrological components of watersheds in Iran on the basis of the IPCC’s Fourth Assessment Report models (AR4). These models together with older emission scenarios have less resolution, in comparison with the Fifth Assessment Report (AR5) models. Thus, climate change studies with higher resolution climate models under the new emission scenarios (RCPs) of the AR5 seem necessary in the watersheds of Iran. Zoshk-Abardeh is one of the important sources of income for the regional villagers and has a high ecotourism potential in Khorasan Razavi Province, Iran. It is considered as an urban watershed and according to the historical evidence has a high flood potential, as well. Therefore, the identification of climate change effects on the hydrologic regime of this watershed is necessary for water resource planners.

Determining the scouring depth around bridge piers during flood has been considered as one of the main and important parameters in designing the foundations of bridge piers. Thus, it has been the subject of numerous studies to provide precise methods to calculate these elements. Due to the high complexity of this phenomenon and various involved parameters, the utilized empirical relations have not sufficient accuracy and efficiency; accordingly, economic and technical design based on their results is not feasible. In this regard, a new model is provided to estimate the scouring depth around bridge piers using Neuro-Fuzzy Comparative Inference System that optimized by Imperialist Competitive Algorithm. Comparing the results of proposed model with the results of base models showed that the accuracy and efficiency of the base models increased significantly with these optimizations. In addition, comparing the results of proposed models with the results of empirical relations from Mississippi, HEC-18, Laursen & Toch, and Froehlich showed that proposed model has significantly better accuracy in comparison with mentioned experimental relations.

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

Establishing a bridge in a waterway changes flow characteristics. Most of these changes derive from geometric details of bridge. Circular and pointed (nested) arches have been used as opening geometry in historical bridges. Historical bridges are valuable heritage and protection of them is important because of cultural continuity. Hydraulic study is a tool to recognize these structures and their design philosophy. In this research, effect of three opening geometry on backwater and hydraulic jump phenomena was numerically studied by Flow-3D software. The FLOW-3D software was selected because not only previous studies indicated that flow around a bridge as well as in a compound channel involves significant 3D characteristics but also it is a powerful hydraulic engineering design tool to model 3D free surface flows. The performance of FLOW-3D was tested using of experimental data obtained from test series which were conducted at the Hydraulic Laboratory, Birmingham University on two opening semi circular bridge model in compound channel (AMOSEC) in which the width of model was 0.10 m. Laboratory tests were carried out for low flow conditions without flow contact with the lower bridge deck (21 to 35 lit/sec). In order to study submerged (High Flow) condition, a program has been developed in the MATLAB environment to extrapolate discharges and related normal depth for 40 to 60 lit/sec discharges. Three opening geometry with the same area as AMOSEC model designed in the AutoCAD. DWG files converted into the Stereolithography format and imported into the Flow-3D.The computational domain, 18 m long and 1.213 m wide, was divided into structured grids. This domain involved nonuniform rectangular grids of 950, 100 and 26 to 40 cells in the x-, y- and z-directions, respectively. Inflow boundary condition was specified as discharge. The downstream boundary condition was specified with a constant fluid height equal to the uniform depth. The sidewalls as well as the channel bottom were defined to be no slip boundaries. On the top, the symmetry (atmospheric) boundary condition was assigned to describe the free surface flow condition. Measured uniform flow depth with zero velocities for each run was assigned to each computational cell to set the initial flow condition. Free surface modeled by VOF and turbulence by two equation K-ɛ methods. Then, a total of 27 runs carried out until steady state resulted. The results indicate that pointed arch geometry makes maximum afflux for both low flows (sub-soffit) and high flows (super-soffit) conditions in all models. Emerging Location of afflux at longitudinal axis is the same for all of the models. Length of hydraulic jump for pointed arch geometry is maximum under low flow condition and minimum under high flow condition. Hydraulic jump starts near the pier for rectangular opening geometry in comparison with others. Critical shear stress due to hydraulic jump is minimum for rectangular geometry and maximum for pointed arch in all discharge conditions. Circular opening geometry produces less upstream flooding and less possibility of downstream bed destruction, so it has advantages on pointed arch geometry.Out of the structural reasons, whole of these results may be considered as hydraulic reason of evolution of pointed arch to semi circular geometry from Safavid to Qajar era.

Hydrology cycle of river basins and water resources availability in arid and semi-arid regions are highly affected with climate changes. So that in the recent years, increase of temperature due to increase of greenhouse gases have led to anomaly in the Earth’ climate system. At present, General Circulation Models (GCMs) are the most frequently used models for projection of different climatic change scenarios. Up to now IPCC has released 4 different versions of GCM models including: First Assessment Report models (FAR) in 1990, Second Assessment Report models (SAR) in 1996, Third Assessment Report models (TAR) in 2001 and Fourth Assessment Report models (AR4) in 2007. The purpose of this study is to survey the annual trend of the future climate components in kashafrood watershed basin (located in the northeastern part of Iran and in the khorsan razavi province) by using fifth report of Intergovernmental panel on climate change (IPCC) under new emission scenarios.
Material and In this research, keeping in view the importance of precipitation and temperature parameters, fourteen models obtained from the General Circulation Models (GCMs) of the newest generation in the Coupled Model Intercomparison Project Phase 5 (CMIP5) were used to forecast the future climate changes in the study area. In historical time (1992-2005), simulated data of these models were compared with observed data using four evaluation criteria for goodness-of-fit including Nash-Sutcliffe (NS), Percent of Bias (PBIAS), coefficient of determination (R2) and the ratio of the root mean square error to the standard deviation of measured data (RSR).
According to performance criteria, among 14 models used in this research, four was chosen as the best namely GFDL-ESM2G, IPSL-CM5A-MR, MIROC-ESM and NorESM1-M which indicated more agreement with observed data. Furthermore, four Representative Concentration Pathways (RCPs) of new emission scenario, namely RCP2.6, RCP4.5, RCP6.0 and RCP8.5 under three future periods: near-century (2006-2037), mid-century (2037-2070) and late-century (2070-2100) were investigated and compered.
The results of Mann-Kendall (MK) test which was applied to examine annual trend, revealed that the precipitation have a variable positive and negative trends which were statistically significant. Also mean, maximum and minimum temperature have a significant positive trend with 90, 99 and 99.9% confidence level. On the other hand, in all parts of the Kashafrood Watershed Basin (KWB), average temperature of watershed increased up to 0.56 °C - 3.3 °C and precipitation decreased up to 10.7% until the end of the 21st century in relation with the historical baseline.

Since the fishway serves important roles in fish migration and survival, they are the main components of river cross structures like dams. In this study, the numerical modeling of Canoe-fishways was conducted using Flow-3D software. For verification, it was used as the results of experimental modeling. By comparing numerical results with experimental model, it was found that the error rates for the depth and velocity of flow were 3 and 11.5%, respectively. Then, using numerical models, the velocity of flow was shown in different directions for optimization discharges, a low-velocity area in pools was found after each brush was formed which was the best place for resting of migratory fishes. Providing the amount of turbulence in different parts of the canal, it was determined that the maximum turbulence occurred in the canal slot. The maximum velocity occurred in slot and in pool front slot. It was also found that velocity and turbulence in different parts of the canal were within the allowable range.

Hydrology cycle of river basins and water resources availability in arid and semi-arid regions are highly affected by climate changes, so that recently the increase of temperature due to the increase of greenhouse gases have led to anomaly in the Earth’ climate system. At present, General Circulation Models (GCMs) are the most frequently used models for projection of different climatic change scenarios. Up to now, IPCC has released four different versions of GCM models, including First Assessment Report models (FAR) in 1990, Second Assessment Report models (SAR) in 1996, Third Assessment Report models (TAR) in 2001 and Fourth Assessment Report models (AR4) in 2007. In 2011, new generation of GCM, known as phase five of the Coupled Model Intercomparison Project (CMIP5) released which it has been actively participated in the preparation of Intergovernmental Panel on Climate Change (IPCC) fifth Assessment report (AR5). A set of experiments such as simulations of 20th and projections of 21st century climate under the new emission scenarios (so called Representative Concentration Pathways (RCPs)) are included in CMIP5. Iran is a country that located in arid and semi-arid climates mostly characterized by low rainfall and high temperature. Anomalies in precipitation and temperature in Iran play a significant role in this agricultural and quickly developing country. Growing population, extensive urbanization and rapid economic development shows that Iran faces intensive challenges in available water resources at present and especially in the future. The first purpose of this study is to analyze the seasonal trends of future climate components over the Kashafrood Watershed Basin (KWB) located in the northeastern part of Iran and in the Khorsan-e Razavi province using fifth report of Intergovernmental Panel on climate change (IPCC) under new emission scenarios with Mann-Kendall (MK) test. Mann-Kendall is one of the most commonly used nonparametric tests to detect climatic changes in time series and trend analysis. The second purpose of this study is to compare CMIP5 models with each other and determine the changes in rainfall and temperature in the future periods in compare with base period on seasonal scale in all parts of this basin. In this research, keeping in view the importance of precipitation and temperature parameters, fourteen models obtained from the General Circulation Models (GCMs) of the newest generation in the Coupled Model Intercomparison Project Phase 5 (CMIP5) were used to forecast the future climate changes in the study area. In historical time (1992-2005), simulated data of these models were compared with observed data (34 rainfall and 12 temperature stations) using four evaluation criteria for goodness-of-fit including Nash-Sutcliffe (NS), Percent of Bias (PBIAS), coefficient of determination (R2) and the ratio of the root mean square error to the standard deviation of measured data (RSR). Furthermore, all models have a very good rating performance for all of the evaluation criteria and therefore investigation is done for precipitation data as an important component in survey of climate subject to select the optimum models in kashafrood watershed basin. By comparing four evaluation criteria for fourteen models of CMIP5 during historical time, finally, four climate models, including GFDL-ESM2G, IPSL-CM5A-MR, MIROC-ESM and NorESM1-M which indicated more agreement with observed data according to the evaluation criteria were selected. Furthermore, four Representative Concentration Pathways (RCPs) of new emission scenario, namely RCP2.6, RCP4.5, RCP6.0 and RCP8.5 were extracted, interpolated and then under three future periods, including near-century (2006-2037), mid-century (2037-2070) and late-century (2070-2100) were investigated and compered. The results of Mann-Kendall test which was applied to examine the trend, revealed that the precipitation have variable positive and negative trends which were statistically significant. In addition, mean temperature have a significant positive trend with 90, 99 and 99.9% confidence level. In seasonal scale, survey of climatic variable (rainfall and mean temperature) showed that the maximum and minimum of precipitations occur during spring and summer and mean temperature in all seasons is higher than historical baseline, respectively. Maximum and minimum of mean temperature occur in summer and winter, and the amount of seasonal precipitation in these seasons will be reduced. Finally, across all parts of kashafrood watershed basin, rainfall and mean temperature will be reduced and increased, respectively. In conclusion, models of CMIP5 can simulate the future climate change in this region and four models of CMIP5 can be used for this region.

Sediment control at lateral intakes is known as a complicated issue for river engineers. In this study, numerical simulation of the impact of submerged vanes and spur dike on sediment control at lateral intake has been performed. For guiding flow into the diversion channel and increasing the vane performance, a single spur dike in opposite side of the intake has been utilized and the effects of spur dike length, the location of intake, and the angle of attack on reducing the movement of bed-load sediment into the diversion channel have been investigated. Obtained numerical results consisting with the experimental data confirmed this face that the effective performance of the vanes can increase using a proper spur result in eliminating the bed-load sediment ingestion rate into diversion channel. Then, numerical results were compared with experimental results and there was good agreement between them.

Settling basins are considered as a major and important component in conventional water treatment processes. The high cost of constructing these basins accounts for approximately 30% of the total capital investment of water treatment plants. Hence, it is essential to model and optimize their performance beforehand. In settling and sedimentation basins, different areas of flow including secondary and rotational flows occur due to the velocity gradient. Such phenomena cause short paths, increase flow stationary and dead zones, and change the mixing rates of the flow, which collectively prevent laminar conditions to be created for the sedimentation process, and thereby reduce process efficiency. The remedy is to reduce as far as possible the dead zones in the flow. The first step to optimize a settling basin is to calculate accurately the velocity field and the volume of rotation zones. The present study presents the numerical simulation of a flow in a rectangular basin. Continuity and Navier-Stokes equations are solved using finite volume method. A 3D flow simulation is performed using the standard k-ε turbulence model for settling basins with and without baffles. Finally, the numerical results obtained are compared with experimental results reported elsewhere.

When a structure is placed on an erodible bed, it causes an increase in local sediment transport capacity and consequently this leads to scour in the vicinity of the structure. This is referred to as local scour in the literature. Local scour has been identified as one of the key factors that cause failure of structures in the bridges, jetties and offshore platforms. The complexities of bridge scour mechanism have caused the scour to be one of the most active topics in civil engineering researches. Numerous studies have been reported on local scour around bridge piers in steady currents in the last decades. A majority of these studies deal with laboratory model studies. A brief literature review can reveal the importance of this subject. Several methods have been proposed by researchers to control the scour around the bridge piers. These methods can be divided into two main categories: the first one is the armoring method or increasing the resistance of the bed material around the pier as rip rap, and the second one is altering of the flow pattern around the pier.