فهرست مطالب جعفر چابک پور

Water distribution network is a system consisting of pipe, water reservoir, pump and valves. Water-supply networks in the hydraulic systems for water transmission and distribution have always been considered by researchers. The hydraulic behavior of water transmission lines is based on speed, pressure and flow. The possible changes in the consumption pattern, population, network leak and diameter of pipe line as well as potential of pumps need to be reviewed. In this research, the evaluation of hydraulic management of urban water-supply networks was carried out using Water Gems software. This means that the diameter of pipe lines and the level (height numbers) are changed so that the pressure is reached to the standard level in the network. Additionally, with modeling this township in Water Gems network in addition to the management of pressure, other data including speed, flow and demand rate are also provided. The first mode is based on the true state of water and sewage network was modeled in Semnan province. The second mode network according to the first mode was modified by changing the diameter of the pipes used to supply standard pressure and negative pressures were destroyed. In the second case by changing the elevation of the standard pressure of the atmosphere was 5-7. The optimum diameter of 85 mm and 180 mm was determined. optimized elevation for reservoir is 1430 meters and by increasing, the low pressure or by reducing, the pressure level rises.

In the last decade, the use of gabion structures in hydraulic engineering for stabilizing the structure due to its high density and weight has become widespread. Also, the material's roughness and porosity cause it to be used in energy dissipation and drainage projects. This study evaluates the relative energy dissipation of gabion structures downstream of the ogee spillway in the conditions of a submerged hydraulic jump. The evaluated parameters in this study were Froude number, gabion height, gabion thickness, and material diameter. The experiments were performed with three average diameters of 1.5, 2.2, and 3 cm for rock material, three gabion heights of 10 and 20 cm, and Max. The end sill heights were 10, 20, and 30 cm. The operated discharges were regulated from 20 to 40 l/s. The results showed that by decreasing the average diameter of gabion aggregates, the amount of relative energy dissipation increases in all tested models, so that in gabion with a 1.5 cm average diameter of aggregates, the amount of energy dissipation increased by 3.6% in comparison with using the diameter of 3cm for the average diameter of the material. Increasing the height of the gabion to the extent that the flow is entirely inward can have up to 33% more relative energy dissipation than the gabion with a height of 10 cm. Also, by increasing the diameter of the gabion from 10 cm to 30 cm, relative energy dissipation increases up to 15%.

The Muskingum model in both types of the linear and non-linear is one the most common models in the flood routing through the river reaches. Because of the similarity between the shape of the flood hydrograph and pollution breakthrough curves, it is tried to examine the applicability of the non-linear Muskingum model in the prediction of the contaminant concentration in downstream of the river reaches. The field data series of the MONOCACY and ANTIETAM Creek Rivers which were gathered by USGS have been used. During the tests, Rhodamine were used and the concentration pollute graphs were acquired in the four and eight cross sections of the mentioned rivers, respectively. The triple sets of the model parameters have been extracted in each reach, then the BC curves have been simulated in each position using them. It is observed that this model can rebuild the dimensions of the exit BC curve properly but, it also has some limitations in the modeling of the convection term of the pollution using average flow velocity. For its solution, the extracted BC curves have been transported along the time axis with magnitude of L/u in which L is reach length and u is the average flow velocity. Also, for better understanding of the effects of the model parameters in the simulated concentrations, the sensitivity analysis have been performed and it is found that the parameters of the m, k and x are the most to less effective parameters in the concentration calculation, respectively.

In the current study, it was tried to determine the mechanism of the tracer penetration through the depth of the river beds to investigate the self-purification nature of the rivers. For this purpose, experimental tests were carried out, and an analytical solution was developed. The electrical conductivity sensors and sodium chloride tracer (as a conservative contaminant) were operated in the operations. Also, for the derivation of the analytical equation, a conceptual model was presented based on the hybrid cells in series model. Then, by imposing the mass conservation to each cell of depth column, the governing differential equation was obtained and solved. Next, the results were evaluated by the framework of the developed equation. Moreover, the applicability of the new model was checked and confirmed by the recreation of the breakthrough curves. The time parameters of the new model were extracted. Then, their variation by the other parameters was queried. It is observed that the sum of temporal parameters (α,T_1,T_2) have a reverse relationship with the vertical dispersion coefficient. On the other hand, its value has been raised by an increment of the bed depth. Furthermore, the product of void scale and the pore velocity has been used for calculation of the vertical dispersion coefficient. Also, the magnitudes of the pore velocity and dispersivity were commuted. It is revealed that by the increase of the bed depth, the mentioned parameters were decreased.

In this research, experimental evaluation of different hydraulic conditions on the performance of gabion sill in dissipating energy at downstream of Ogee spillway has been investigated. The parameters evaluated in this study included: Froude number, sill height, the amount of opening in the sill width and the diameter of the aggregates. The experiments were conducted by using flow discharges of 20 to 40 liters per second with two heights of 5 and 10 cm and openings of 10, 15, 20 and 30 cm in fixed sill widths with and without openings. The results showed by increasing the height of the sill, the relative length of the hydraulic jump increases and the amount of relative energy dissipation also increases. Also, by increasing the diameter of aggregates, the relative length of hydraulic jump and the amount of relative energy dissipation decreased. The highest amount of energy dissipation was related to aggregates with an average diameter of 1.5 cm in which the amount of energy dissipation and the length of hydraulic jump were 9 and 8.3 % more than the ones in 3 cm diameter of aggregates, respectively. The results also showed creating an opening and increasing it across the sill reduces the relative energy dissipation. So that the relative energy dissipation in the gabion with 30 cm opening was about 7% and its relative hydraulic jump length was about 9% less than the ones in sill without opening.

A series of experimental data and two series of field data which have been extracted by USGS in the MONOCACY River and ANTIETAM creek have been utilized to compare source identification accuracy of the Gaussian, ADZ, and VART models. To achieve the object of the study, the theoretical solution of the VART model for sudden release, and the second-order central moment equation of the Gaussian and ADZ models have been operated For all of the experimental and field data series, firstly, all of the model parameters have been computed and then by operation of the extracted parameters and the mentioned relationships, the accuracy of them have been calculated. The results showed that the accuracy of the VART model for experimental and field data is 25% and 4.8% respectively. Also, the average relative errors of the Gaussian and ADZ models are 1.65% and 14%, respectively, which confirms the desirable accuracy of the Gaussian model. The results of the present study have been revealed that the Gaussian model in both of the model parameter numbers and the calculation accuracy is superior to the others. Also, to assess the goodness of fit between experimental and field data series and the theoretical Breakthrough curves, the average Nash-Sutcliffe parameters have been calculated about 0.97, which exhibits the favorable goodness in the fits.

To evaluate the effects of mycorrhizal fungus Funneliformis mosseae application and harvest time on the quantity and quality of thyme (Thymus vulgaris L.) essential oil in the different irrigation regimes, a field experiment was carried out as a split-split plot in a randomized complete blocks design (RCBD) with 12 treatments and three replications at the Agriculture Faculty, University of Maragheh, Iran, in 2019. The factors and their levels included 1- the main factor: irrigation regime at three levels of irrigation after 20% (W20 as control), 50% (W50 as moderate stress), and 80% (W80 as severe stress) of maximum allowable depletion, 2- the subfactor: application and non-application of mycorrhiza, and 3- sub-sub factor: harvest time at two levels of June harvest (first harvest) and September harvest (second harvest). The results demonstrated that the highest amounts of plant height, canopy diameter, and dry matter yield of thyme were obtained in the W20 (control)+ application of mycorrhiza fungus+ first harvest treatment. In addition, the highest essential oil content was recorded in W50 followed by W80, which were 38.2 and 23.7% higher than W20 (control), respectively. Also, the application of mycorrhiza fungus increased the essential oil of thyme by 8.5% compared to the non-application of fungus. The highest and lowest content of thymol, γ-terpinene, and p < /em>-cymene were obtained in W50 and W20, respectively. Also, the application of mycorrhiza fungus increased the amount of mentioned compounds, respectively by 3.8%, 3.9%, and 7.1% compared to the non-application of fungus. Overall, it can be concluded that W50 (moderate stress) along with the application of mycorrhizal fungus F. mosseae improved the essential oil quality and quantity of thyme.

Accurate flood routing through the river reaches is one of the essential issues in the river training activities and flood warning systems. Especially when the river passes near residential areas of cities, it is vital to have enough information about the maximum flow that can flow through the river without damaging its surroundings. Due to the complexity of the complete solution process of Saint-Venant equations, over the years, many researchers have tried to provide alternative models that, in addition to simplicity, have the necessary accuracy. Previous models usually have two significant drawbacks. First, the process of solving most of them is step-by-step, and to calculate the outflow discharge at each time step, the estimated flow in the previous step is required. Second, sometimes the model coefficients change during the resolution process. Therefore, in the present study, an attempt was made to provide a clear and direct relationship. Also, if the coefficients are known for determining the flow rate in each time step, there is no need for the values of the previous steps.

In order to prove the prevailing analytical relationship, in this research, first, the two processes of flood transfer and flood dispersion in the river reaches were conceptually separated. For this purpose, the river reach was divided into three interconnected reservoirs. The first reservoir is an index of the flood convection, and the next two reservoirs were the index of flood propagation process. The runoff volume, obtained from the upper basin, was calculated using multiplying the runoff coefficient to the rainfall height. Then, it was suddenly applied to upstream of the river reach by using the Dirac delta function. By adding the spatial flow variation coefficient to the reservoirs of the propagation operation as well as applying the mass equilibrium and inclining the dimensions of the reservoirs to zero, the differential equations governing each reservoir were obtained. The outflow of each reservoir was used as the boundary condition of the next one, and the final equation, obtained from the interconnected reservoir system, was used as the output hydrograph relationship. In order to evaluate the performance of the introduced model, the data of four flood events that were recorded on (19 - 3 – 2017), (15 - 4 – 2017), (29 - 1 – 2019), and (31 - 3 - 2019) in Simineh River were used. Simineh River is located south of Lake Urmia and provides 11% of the lake's water. The flood data was recorded at three stations of BUCKAN Bridge, DASHBAND BUCKAN, and MIANDOAB Bridge with two-hours interval.

The proposed model is a four-parameter model that works directly by operation of its parameters. Therefore, firstly the model parameters were estimated and then the output hydrograph was simulated at the end of the river reach. The simulated hydrographs by the proposed model were very consistent with the measured data at the end of the interval, indicating its efficiency. Statistical indicators of coefficient of determination (R2), root mean square error (RMSE), and Nash-Sutcliff (DC) were used to quantify the desirability of the model. The above-mentioned statistical parameters for all flood events were calculated as triple sets of (0.86, 0.07, 0.95), (0.82, 0.11, 0.8), (0.97, 0.07, 0.94), and (0.93, 0.1, 0.9), respectively which also proves its quantitative suitability. By creating linear relationships between the residence times of the flood in each of the interconnected reservoirs, the relevant volumes were calculated. It was also found that the length of each reservoir can be calculated separately by applying a mean cross sectional area in the river reach. The flood volume was calculated to be 30, 50, 63 and 37 million cubic meters for events of 1 to 4, respectively. This value is equal to the total volume of the assumed reservoirs in the river reach. Ratio (V/T) was calculated for all reach lengths and flood events, and it was found that its value decreases with the increasing of reach length, but its value for larger floods is higher than for smaller ones. Besides, it was found that the position of the dispersion reservoirs in the river reach can be exchanged with each other, and the total volume of them is the diffusion index.

Finally, it was observed that the proposed model has good compatibility with observational hydrographs, except in the initial points of raising limb. Optimization or numerical methods can also be used to obtain model parameters. Moreover, the explicitness and directness of the discharge calculation by this method is the most crucial advantage of this model. This model also has the capability of reconstructing hydrographs affected by the spatially varied flow.

Some parts of the free surface flow including river networks in which the velocities is low, can act as dead or hyporheic zones. These areas can help to the temporary storage of the tracers and consequently increasing the residence time parameter. In this study, the effects of consecutive reservoirs caused by construction of gabion flood control structures have been investigated in terms of dead zones creation and residence time expansion. For this purpose, 36 experiments were performed in the laboratory flume, including two gabion dams. The experimental variables included three rock median diameters, four entrance discharges and three entrance concentrations. The HCIS model, which includes temporal parameters of the λ, T1, and T2, has been used to obtain the residence time, the reservoirs volume behind the gabion dams and flow hydraulic parameters. The results showed that the transport time parameters were increased linearly with reservoir volume (V) and number (N). Also, linear regressions were established between the number of dams and the other temporal parameters obtained from experimental breakthrough curves (BC). It was found that the slopes of N- and V- ( is total duration time of the BC) linear regressions were bigger than the similar values for  (time from the injection time origin to the rising point of BC curve), indicating a higher residence time due to transient storage of the pollution. Also, it was found that the time parameters obtained from HCIS model are increased linearly with N and distance from the injection point.

Computation of longitudinal velocity in the vertical direction and extracting the applied theories have been conventional manner from past years among the hydraulic engineers. In many previous investigations, the researchers have tried to extract some applied equations, separately, by dividing the flow depth namely from bed to water surface to various regions. As it is accepted by all of the researchers, the laminar sublayer zone has a linear velocity profile while out of this zone, the velocity simulation follows a logarithmic law which its accuracy in estimation of the velocity decreases by increasing the distance from the bottom of the channel. Also, it is not applicable for dip phenomenon which occurs bellow the free surface. In the current study, 12 experimental data series, operated under different experimental conditions, were collected from previous researches. Also, three common theories of log law, log- wake law, and modified log- wake law have been applied to simulate longitudinal velocity profile in the vertical direction. Finally, it is seen that the modified log- wake law has a better agreement with the experimental data, and also it can be operated for predicting the dip phenomenon bellow the free surface. For solving the equation of the mentioned theory, the factors of von Karman, wake strength, and shear velocity are assumed unknown. Then, the mentioned parameters have been extracted using a non-linear optimization technique of the least square curve fitting.

In the present research, it was tried to evaluate the pollution transport in the interconnected reservoirs by deriving a theoretical solution based on the TS model partial differential equations and by conducting an experimental model. The theoretical model has been solved by operation of the Laplace transform to the PDE equations, and a complete evaluation of the model applicability and the parameters’ magnitudes have been fulfilled using experimental data series of two interconnected reservoirs. The created rockfill dams in the laboratory flume have been produced using three different median diameters of the 1.1, 2.3, and 3.6 cm. The other experiment variables were the entrance discharges as 7, 9, 11, and 13.5 l/s and linear source concentration of the 100, 140, and 200 gr/l. The mean values of the velocities, dispersion coefficients, and the logarithm of the mass transfer coefficients between the storage area and the main flow have been determined as 4 cm/s, 2.4 cm2/s, and -10.5 respectively. The corresponding of the experimental breakthrough curves with theoretical ones have been assessed and confirmed using statistical parameters of the RMSE and Nash-Sutcliff, having the values of 0.21 and 0.7, respectively. In the present research, it was tried to evaluate the pollution transport in the interconnected reservoirs by deriving a theoretical solution based on the TS model partial differential equations and by conducting an experimental model. The theoretical model has been solved by operation of the Laplace transform to the PDE equations, and a complete evaluation of the model applicability and the parameters’ magnitudes have been fulfilled using experimental data series of two interconnected reservoirs. The created rockfill dams in the laboratory flume have been produced using three different median diameters of the 1.1, 2.3, and 3.6 cm. The other experiment variables were the entrance discharges as 7, 9, 11, and 13.5 l/s and linear source concentration of the 100, 140, and 200 gr/l. The mean values of the velocities, dispersion coefficients, and the logarithm of the mass transfer coefficients between the storage area and the main flow have been determined as 4 cm/s, 2.4 cm2/s, and -10.5 respectively. The corresponding of the experimental breakthrough curves with theoretical ones have been assessed and confirmed using statistical parameters of the RMSE and Nash-Sutcliff, having the values of 0.21 and 0.7, respectively. In the present research, it was tried to evaluate the pollution transport in the interconnected reservoirs by deriving a theoretical solution based on the TS model partial differential equations and by conducting an experimental model. The theoretical model has been solved by operation of the Laplace transform to the PDE equations, and a complete evaluation of the model applicability and the parameters’ magnitudes have been fulfilled using experimental data series of two interconnected reservoirs. The created rockfill dams in the laboratory flume have been produced using three different median diameters of the 1.1, 2.3, and 3.6 cm. The other experiment variables were the entrance discharges as 7, 9, 11, and 13.5 l/s and linear source concentration of the 100, 140, and 200 gr/l. The mean values of the velocities, dispersion coefficients, and the logarithm of the mass transfer coefficients between the storage area and the main flow have been determined as 4 cm/s, 2.4 cm2/s, and -10.5 respectively. The corresponding of the experimental breakthrough curves with theoretical ones have been assessed and confirmed using statistical parameters of the RMSE and Nash-Sutcliff, having the values of 0.21 and 0.7, respectively. In the present research, it was tried to evaluate the pollution transport in the interconnected reservoirs by deriving a theoretical solution based on the TS model partial differential equations and by conducting an experimental model. The theoretical model has been solved by operation of the Laplace transform to the PDE equations, and a complete evaluation of the model applicability and the parameters’ magnitudes have been fulfilled using experimental data series of two interconnected reservoirs. The created rockfill dams in the laboratory flume have been produced using three different median diameters of the 1.1, 2.3, and 3.6 cm. The other experiment variables were the entrance discharges as 7, 9, 11, and 13.5 l/s and linear source concentration of the 100, 140, and 200 gr/l. The mean values of the velocities, dispersion coefficients, and the logarithm of the mass transfer coefficients between the storage area and the main flow have been determined as 4 cm/s, 2.4 cm2/s, and -10.5 respectively. The corresponding of the experimental breakthrough curves with theoretical ones have been assessed and confirmed using statistical parameters of the RMSE and Nash-Sutcliff, having the values of 0.21 and 0.7, respectively.

The Easiness of mining from the rivers and its low cost have increased use of these resources. In the present study, the effects of pit migration and development on the bridge inline piers were investigated experimentally. The circular and sharp rectangular shapes of the piers have been employed in this study. The results showed that the pit holes are developed to the downstream and upstream bridge piers in order to achieve sediment balance, which causes piers scouring at downstream and upstream. Also, the development of the holes towards upstream pier is more than the downstream pier. Regarding to aero-dynamical shape of the rectangular sharp nose bridge, the magnitude of the scouring hole at the up and downstream is reduced 24.5 and 31.55% respectively as compared to circular piers. Finally, the empirical relationships related to the maximum length and depth of scouring were derived. By using these relationships, the geometric and effective statistical parameters on the pier scouring, as well as the relative error percentage and RMSE of the obtained functions were evaluated and the depended graphs were depicted. It was found for both sediment dimensions, by reduction of the hole depth and Fr number, the dimensionless parameter of the H/y(the pit holes depth to flow depth) is decreased and the L/y and B/y (the pit holes length and width to flow depth) parameters are increased. Finally, the parameters affecting the maximum length and depth of the pit scouring were identified and introduced for both sharp piers.

In this research, the applicability of the screen sheet, as an energy dissipater at downstream of hydraulic structures, has been studied to reduce the amount of scouring. For operation of the experiments, a rectangular flume with 0.3m in width, 0.45m in height and 5m in length, including a sluice gate for the flow control was used. For reducing energy of outflow from sluice gate, the screen sheets as energy dissipaters with 40% and 50% porosity were placed at distance of 1.5m from the gate. After the screen sheet, the movable beds consist of three different grain sizes of 1.8, 2.6 and 5.2 mm, with the dimensions of 1.3m in length, 0.3m in width and 11.4cm in depth were used to investigate the effect of screen on maximum dimensions of the scouring hole. The results of this study showed that the thickness and porosity of the screen and its distance from the gate are effective parameters on the lenghth and depth of scouring hole. The maximum and minimum depth and length of scouring hole were occurred in the screens with 40% porosity and double 50% porosity, respectively. So that, by increasing the screen’s porosity and thickness, the scouring whole dimension decreases. Also, by increasing the particle dimensions, the scouring hole dimension decreases.

Application of simple and accurate routing models in the flood warning systems increases the capabilities of them. In the present study, it was attempted to fulfil the flood routing using ADZ model and its discrete time form which is named transfer function in the three river reaches, located between six hydrometric stations along the ZARINE and SIMINEH streams. Daily river’s discharges during 15 years (2001-2015) have been employed in the reach routing. Firstly, the numbers of the numerator and denominator terms have been obtained. These parameters are giving the numbers of the subzones in every river reach and also the conditions of the connections (series or parallel). The results of the present study revealed only one sub reach for every river. Therefore, any more analysis of the connection conditions has not been done. After that, the values of the transfer function’s coefficients have been derived using micro CAPTAIN toolbox. The statistical parameters of the mentioned toolbox as ((YIC), (Rt2), and (EVN) for the reaches of the DASHBAND BOUKAN-BOUKAN bridge, ALASAGGAL-SAFAKHANEH, and GESHLAGH bridge- ANIAN bridge have been determined as triple sets of (-5.241, 0.879, -10.86), (-3.954, 0.903, -9.43), and (-2.792, 0.920, -8.139) respectively. The outcomes exhibited a right corresponding between the theoretical graphs, obtained with the transfer function, and observed discharges. The transfer function method is more straightforward rather than the other accurate methods of flood routing like fully saint venant equations. Therefore, it can be used as an efficient method in the flood routing in the river reaches. Application of simple and accurate routing models in the flood warning systems increases the capabilities of them. In the present study, it was attempted to fulfil the flood routing using ADZ model and its discrete time form which is named transfer function in the three river reaches, located between six hydrometric stations along the ZARINE and SIMINEH streams. Daily river’s discharges during 15 years (2001-2015) have been employed in the reach routing. Firstly, the numbers of the numerator and denominator terms have been obtained. These parameters are giving the numbers of the subzones in every river reach and also the conditions of the connections (series or parallel). The results of the present study revealed only one sub reach for every river. Therefore, any more analysis of the connection conditions has not been done. After that, the values of the transfer function’s coefficients have been derived using micro CAPTAIN toolbox. The statistical parameters of the mentioned toolbox as ((YIC), (Rt2), and (EVN) for the reaches of the DASHBAND BOUKAN-BOUKAN bridge, ALASAGGAL-SAFAKHANEH, and GESHLAGH bridge- ANIAN bridge have been determined as triple sets of (-5.241, 0.879, -10.86), (-3.954, 0.903, -9.43), and (-2.792, 0.920, -8.139) respectively. The outcomes exhibited a right corresponding between the theoretical graphs, obtained with the transfer function, and observed discharges. The transfer function method is more straightforward rather than the other accurate methods of flood routing like fully saint venant equations. Therefore, it can be used as an efficient method in the flood routing in the river reaches. Application of simple and accurate routing models in the flood warning systems increases the capabilities of them. In the present study, it was attempted to fulfil the flood routing using ADZ model and its discrete time form which is named transfer function in the three river reaches, located between six hydrometric stations along the ZARINE and SIMINEH streams. Daily river’s discharges during 15 years (2001-2015) have been employed in the reach routing. Firstly, the numbers of the numerator and denominator terms have been obtained. These parameters are giving the numbers of the subzones in every river reach and also the conditions of the connections (series or parallel). The results of the present study revealed only one sub reach for every river. Therefore, any more analysis of the connection conditions has not been done. After that, the values of the transfer function’s coefficients have been derived using micro CAPTAIN toolbox. The statistical parameters of the mentioned toolbox as ((YIC), (Rt2), and (EVN) for the reaches of the DASHBAND BOUKAN-BOUKAN bridge, ALASAGGAL-SAFAKHANEH, and GESHLAGH bridge- ANIAN bridge have been determined as triple sets of (-5.241, 0.879, -10.86), (-3.954, 0.903, -9.43), and (-2.792, 0.920, -8.139) respectively. The outcomes exhibited a right corresponding between the theoretical graphs, obtained with the transfer function, and observed discharges. The transfer function method is more straightforward rather than the other accurate methods of flood routing like fully saint venant equations. Therefore, it can be used as an efficient method in the flood routing in the river reaches. Application of simple and accurate routing models in the flood warning systems increases the capabilities of them. In the present study, it was attempted to fulfil the flood routing using ADZ model and its discrete time form which is named transfer function in the three river reaches, located between six hydrometric stations along the ZARINE and SIMINEH streams. Daily river’s discharges during 15 years (2001-2015) have been employed in the reach routing. Firstly, the numbers of the numerator and denominator terms have been obtained. These parameters are giving the numbers of the subzones in every river reach and also the conditions of the connections (series or parallel). The results of the present study revealed only one sub reach for every river. Therefore, any more analysis of the connection conditions has not been done. After that, the values of the transfer function’s coefficients have been derived using micro CAPTAIN toolbox. The statistical parameters of the mentioned toolbox as ((YIC), (Rt2), and (EVN) for the reaches of the DASHBAND BOUKAN-BOUKAN bridge, ALASAGGAL-SAFAKHANEH, and GESHLAGH bridge- ANIAN bridge have been determined as triple sets of (-5.241, 0.879, -10.86), (-3.954, 0.903, -9.43), and (-2.792, 0.920, -8.139) respectively. The outcomes exhibited a right corresponding between the theoretical graphs, obtained with the transfer function, and observed discharges. The transfer function method is more straightforward rather than the other accurate methods of flood routing like fully saint venant equations. Therefore, it can be used as an efficient method in the flood routing in the river reaches.

The removal of sand and gravel from the bed and the banks of the rivers cause to change in the hydraulic and hydrology conditions of them as well as the aggradation and degradation processes in the bed and the banks and also the destruction of existing structures along the river. The purpose of the present study is to study the pit migration (maximum depth and length of the holes) due to the material extraction. For this research, a rectangular experimental flume with length, width, and height of (5, 0.3, 0.45) meters was used. The longitudinal slope was fixed to zero. The pit holes with different sizes and different entrance discharges including relative velocities of 0.83, 0.89, 0.94 and 1, have been operated. The experiments have been accomplished with or without downstream gate by using two sediments mean dimensions of the 0.15, 0.6 mm. In this study, the duration of the experiments, were fixed to 1 and 1.5 hours respectively for including and without end gate flow conditions. such that the equilibrium time for both of them was the last 15 minutes. A 3D laser scanner was also used to take data from the bed profile after flow disconnection. Also from the side view of the experimental flume, the digital photos were taken to view the conditions of the pit propagation at different time intervals. Afterward, using the MATLAB, Tec-Plot 360 and Grapher software tried to rearrange the data series for 2 and the 3-dimensional view from time variation of the pits were extracted. During the experiments, the bedforms at the down and upstream of the pit holes were observed and their temporal variations were recorded. The results of the experiments showed that with decreasing of the Froude number, pit depth and also by creation of the secondary currents inside the holes, the dimensionless ratio of the decreases and reversely, the dimensionless parameters of the and increases. On the other hand, it was concluded that by increasing the Froude number and shear stress, the dimensionless ratio of the would be increased. The longitudinal profiles and 3D view of the pit migration at the all of the sediment and flow conditions were observed and depicted. At the end, the experimental equations of the maximum scouring length and depth of the pit hole were presented. In general, it was shown that the submerged angle of repose of materials ( ) has the highest direct effect and the dimensionless ratio of has the highest reverse effect on the maximum scouring length and depth of the pit hole. The extracted relationships with experimental data were verified by means of the other set of data series and the results were quite satisfactory. The results of the experiments have been illustrated by presenting the none-dimensional relationships for maximum depth and length of the pits under gated and none-gated conditions. The effects of the variation of the sediment dimension and flow conditions were also discussed. It was proved that the lowest error percent for maximum scour depth was observed in the 0.15 mm mean sediment particles, having the relative error of 2.98% and RMSE of 0.23. Also, the lowest error percent of the maximum scour length is related to a 0.6 mm mean sediment particles with a relative error of 7.45% and an RMSE of 0.5.

This research was conducted to test how to exchange mass between the main channel and the stagnant areas of the stream. The transient storage differential equations were selected as the governing equations for simulation of advection- diffusion of pollution in river flow. The experiments were conducted in a gravel bed flume, with length, width and depth of 12, 1.2 and 0.8m, respectively. Three longitudinal slopes of 0.001, 0.004 and 0.007 and three discharges of 7.5, 11.5 and 15.5 (l/s) were selected for the experiments. The numerical model of OTIS-P was used to estimate the four parameters of the transient storage model. Then the observed breakthrough curves were regenerated at the same locations of measured points. Goodness of fit was estimated with the root mean square error (RMSE), Nash and Sutcliffe model efficiency coefficient (NS) and the mean absolute error (MAE). The comparisons revealed that the OTIS-P model (with RMSE between 0.031- 0.118 and Nash- Sutcliffe between 0.48-0.9) could be employed successfully for estimation transient storage parameters. Finally, the reliability of the estimated parameters of the transient storage model was confirmed by the non-dimensional Dam-kohler number.

The longitudinal dispersion coefficient from the perspective of public safety and human health, is one of the important parameters for predicting and characterizing the transport of pollution in rivers and shallow waters. This paper aimed at investigating the efficiency of the classical advection- dispersion Equation for predicting transport of pollution in a gravel bed rivers. Some tracer experiments were done in a flume with longitudinal slopes of (S= 0.001, 0.007) and five discharges include of (7.5, 11.5, 15.5, 20.5, 25.5) lit/sec. Simulated (OTIS) and analytical breakthrough curves were compared with observed data. The results of this study indicated that advection- dispersion equation in prediction of tailing edge of breakthrough curve has less accuracy. So it not be used in rivers with storage area but it is very helpful to estimate initial value of longitudinal dispersion coefficient. The calculated dispersion coefficient increased with augmentation distance from the injection site. The domain of estimated dispersion coefficient for the tracer test of this research is between (0.0073- 0.18) m2/sec. the results of calculating travel time parameters from experimental BT curves showed an exponential relationship between them and the distance from the injection site. Finally, using a geometric, hydraulic, and tracer test data and applying a Buckinghamۥ π theorem a new equation was developed to predict the longitudinal dispersion coefficient. The relative error and normalized root mean square error for the proposed equation were calculated respectively 24% and 1.37.

Water quality assessment of rivers, in order to insure human health and environmental sustainability, is one of the most important purposes of the physical and numerical models of solute transport in rivers. In this research, some tracer experiments were done and also the numerical model of OTIS was used to simulate solute transport. This model predicts the solute BT curve for a given hydraulic and geometrical parameters at downstream sections of river with respect to concentration of pollutant resource at upstream boundary condition. The experiments were conducted in a flume with length, width and depth of 12, 1.2 and 0.8m. Two longitudinal slopes of 0.004 and 0.007 and three discharges of 7.5, 11.5 and 15.5 (l/s) were selected for the experiments. A given mass of NACL solution was instantaneously injected into upstream of the flume and then the breakthrough curves were plotted based on the measured electric conductivity values along the centerline of the flume for the different sections at downstream of the injection point. To assessment the goodness of the simulated and observed BT curves, the statistical indices including the root mean square error (RMSE), Nash and Sutcliffe (NS) and mean absolute error (MAE) were extracted. With comparison of the observed BT curves with the numerical results (obtained with OTIS), the longitudinal dispersion coefficient values in different reach of flume were calculated. Analysis of the results showed that for a constant longitudinal slope and discharge, by increasing the distance from the injection location, the coefficient of dispersion was increased. Also, for constant slope, with enhancing the discharge rate, the dispersion coefficient was increased but for a given discharges, the dispersion coefficient was decreased with increasing the longitudinal -slope.

In this research tried to examine the transport and dispersion characteristics of rockfill media with application of the two completely flowthrough discharges, two media diameters and five injection masses. Firstly by means of a digital EC sensors and related data logger system and software, the experimental BC curves have been extracted and then by application of method of temporal moments, the longitudinal dispersion coefficient and other parameters like mean residence time, variance and coefficient of skewness have been computed. Afterwards, by using analytical solution of classical advection dispersion equation and extracted coefficients from method of moments, the theoretical BC curves have been calculated and were compared with experimental ones. The applicability of method of moments have been approved by the results and also concluded that (except the climax point, in some cases) the theoretical solution can cover all regions of experimental BC curve.

Rockfill material is frequently used in construction of hydraulic structures. The cross flow regime which is mostly None-Darcy regime and estimation of friction coefficients have been investigated frequently. Many researchers have studied the relationship between Reynolds number and friction coefficient in both power and fractional forms. In this research, by using two types of rock material namely with: median diameters of , , three entrance discharges and three hydraulic gradients the important factors in estimation of friction coefficients was investigate. Results showed that against results of previous studies, in flow through rockfill media, having free water surface, the Froude Number demonstrated a better relationship with friction coefficient rather than Reynolds Number. Also it was observed that due to the formation of M2 longitudinal profile through the rackfill media, the active cross section along the profile decreases and consequently the friction coefficient towards exit of media decreases. Further it can be concluded that the computed friction coefficients for completely flow through the medias are much higher than friction coefficients of channel free surface flows. Finally an attempt was made to draw the relationships in power form between effective none-dimensional parameters like Froude number, geometric ratio of flow depth and rock diameter and friction coefficients in two form of Manning and darcy-weisbach. Using combination of two none-dimensional parameters (Froude number and geometric ratio of flow depth and media diameter) two applicable relationships for darcy-weisbach and manning coefficients have been presented which have estimation accuracies of 14 and 26 percent respectively.

Rock fill materials are among the useful materials in operation of hydraulic structures that are being frequently used by engineers and designers of hydraulic structures, because of lower cost and environmental sustainability. Knowing of water profile is valuable for practical purposes and designing, sometimes observed that because of mining or roadway operations in vicinity of rivers, the rock materials were fallen to river bed and changed the flow regime from open channel flow to the None-Darcy inner flow. Another use with these materials is in building of rock fill detention dams for flood mitigation in river downstream, which nowadays become so common in Iran. These dams temporary reserves the flood in its low capacity reservoir and then passes from its body with delay. Flow through large porous media could be interpreted with both equations of pipe and open channel flow. Since the flow in rock drains or detention dams have a free surface, it is usual to apply open channel equations like GVF in profile estimation. Different types of numerical or theoretical equations have been employed by previous researchers for its solving, but it should be mention that in these type problems, the method would be valuable which could be applied easily. Therefore, single step direct numerical methods were selected in the present study. Furthermore, because of nature of water surface profiles inside the rock fill dumps, the method of calculation could be capable for estimation of the flow depth according to the profile length.
For laboratory data collection, an experimental setup was created in which the semi crashed riddled rock materials placed between two vertical screen walls such that a grid of Piezometric tubes had been positioned in the centerline of rock media. By changing of media size and length, the different type of physical configurations created. Then by employing of four different discharges, the surface profile acquired. The photography and digitizing technic have been used for experimental data extraction. Moreover, water supply system of the flume has been connected to the constant head tank of laboratory, and the discharges were measured by means of pre-calibrated V notch. In this research, water surface profiles were obtained experimentally by two rock diameter, two media length and four operation discharges. Then, by using of gradually varied flow equation and three numerical methods including Euler, modified Euler and 4th order Range-Kutta, The water surface profiles were simulated numerically and compared with experimental profiles. In all of these methods the exit point height from the experimental data series were employed as the boundary condition. The flow condition at that point is generally different from other parts of rock body. Different researchers have presented some relationships for exit height, but most of them related it to the critical height in the particular discharge. By focus on experimental observations, Because of existing of large slope in surface profile, the flow regime changes rapidly and the GVF equation may be unsuitable in the mentioned regions but because of low length of it the discrepancy in profile calculations is negligible. Therefore, more research is needed to investigate it in details and disquisition around it is not from the purposes of this research. One of the most important subjects of profile estimation is to calculate pore velocity which is dependent on media size and porosity. Previously, several types of pore velocity equations have been presented, but the most famous one is the Wilkins relationship. Because of None-Darcy and turbulent nature of inflow, the relationship between hydraulic gradient and pore velocity is quadratic and the effect of first term of Forchheimer’s equation is negligible.
After acquisition of experimental surface profile in different flow and physical configuration of laboratory setup and programming of the selected numerical methods in MATHLAB software, the comparisons of results were done. Then it was observed that 4th order Range-Kutta method with 4th order accuracy has the better estimation accuracy rather than other two methods with average RMSE equal to 1.19 and average R2 equal to 0.9. Also, it should be mentioned that because of the large magnitude of hydraulic grade in exit regions of porous media, use of Range-Kutta method imposes some errors in the profile estimation in the exit region. Therefore, application of modified Euler at the aforementioned zone has the better conclusions.

In many flowthrough patterns from body of rockfill dams or long rock drains with free water surface, modeling of advection and dispersion of pollutants is one of most important issues. In this research with application of sodium chloride as tracer and EC sensors installed inside the rockfill media, experimental breakthrough curves were extracted. Then with analytical solution of unsteady advection- dispersion equation and none linear optimization least square technique the analytical breakthrough curves at the positions of sensors were also determined. The data acquisition instrument consisted of EC sensors, data logger and application software. Two types of rocks with diameters of 1.1 and 1.8 centimeters, two completely flowthrough discharges of 0.26 and 0.37 liters per second and 5 injection mass of sodium chloride 5, 10, 15, 25 and 50 grams were the variables of laboratory experiments. Finally it was observed that against normal distribution of mass which is special and symmetric case of equation, the observed BC curves were asymmetric in raising and falling limbs. They had longer tail in falling limb because of transient storage of tracer inside the rock media and gradually transport towards the downstream. It was concluded that the classical AD equation is suitable for predicting the general trend of BC curves. In many cases it was observed that the peak point in the analytical solution is lower than the experimental one. Average magnitudes of RMSE, CRM, MAE and ME the statistical parameters for simulated concentration data were 1.35, 0.000608, 52.9ppm and 648.8 ppm respectively which showed a good agreement between experimental and analytical data series.

Applicability of rockfill dams which has been made from large rock materials for purpose of flood detention reduces over the time because of siltation of pore system with sediment contained basin outflow. Since some of structures which were built with large rock materials should convey suspended sediment contained flows therefore routing process of these type flows have been investigated. The investigation around advection and dispersion of sediments particles through the large porous media usually is being done with breakthrough curve. This investigation is usually common for pollutants in rivers, sewer system and fine porous media. Previous researchers used from various techniques like numerical solving, parameter estimation and exact solution for solving of above mentioned problems. But unfortunately any general inquiry about suspended sediments was not accomplished yet. The exit breakthrough curves in many cases are asymmetrical and have Skewness in their falling limbs. Therefore some researchers after collecting the series of field data have discovered it and have presented a new model named transient storage model. Some investigators by considering Asymmetry in exit breakthrough curve have joined first order mass transfer equation with ADE equations and have extracted exact solutions with various primary and boundary conditions. The important criterion in this regard is to use them in similar primary and boundary conditions. Therefore in many cases the investigators are using from temporal and spatial moment technique according to experimental data series. By emphasis to above mentioned criteria and as regards to this fact that any coherent research in the investigation of behavior of suspended sediments through the large porous media were not accomplished yet therefore in this research tried to focus on it.
In this research by creating a laboratory model of large porous media and employing suspended sediment particles, tried to acquire an experimental data series in order to investigate longitudinal convection and dispersion phenomenon of suspended sediments through the large porous media. In this investigation by application of 2 media diameters, 4 inflow discharges and different hydraulic gradients over the media, the breakthrough curves of suspended sediments were extracted. The BC curves were extracted with water sampling from media end and then the samples have been passed from filter paper and dried. The concentration-time graphs were extracted after weighting of dried sediment particles. Also by using of parameter estimation technique for classical advection dispersion equation and temporal moments method, the longitudinal dispersion coefficients were extracted.
The results showed that due to the inherent properties of exit breakthrough curve, the temporal moments method has a better estimation accuracy rather than classical advection dispersion equation. Additionally by dimensional analysis method a relationship has been acquired for estimation of longitudinal dispersion coefficient with average relative error of 30% which is reliable in sediment transport studies. Furthermore, the results of analysis of BC curves exhibited that the curve has an Asymmetric limbs in rising and falling stages which this observation is because of temporary storage of sediments and gradual release of them through the downstream flow.