In transient flow velocity and pressure change with respect to time. Detection of leak location and size in water pipelines and networks is one of the important applications of transient flow analysis. The purpose of all transient-based leak detection methods is similar and it is to supply information about leak properties using transient flow data. Oil and water pipelines are usually expose to leakage problems. Insufficient fresh water resources especially due to recent droughts and also shortage oil resources is a clear reason for importance of pipeline monitoring. So, protecting and prevent from wasting of these resources is a social duty. Leakage from water pipeline can causes water pollution and Leakage from oil pipeline can contaminate the environment. Detecting the leak and repairing the pipeline can have effective environmental aspects. Therefore, a physical model established made up of PE – PN16 pipe with 158m length to study the effect of leakage on transient flow and then, using the Gene Expression algorithm, simple relations were obtained to determine the leakage characteristics, including the leakage location, the leakage size, and the amount of leakage generated by the leakage system through transient currents. Effect of leakage on hydraulic characteristics of transient flow, damping of pressure wave and different friction models with their coefficients were studied in numerical and experimental models. Studies show that sudden valve closer provide more accurate data for leak detection purposes in comparison to slow valve closure. The effect of leak on first peak of pressure wave is clear in all of experiments. Rate of pressure wave damping is greater for larger leak diameters. Increasing the leak diameter from 3mm to 8mm, headloss will raise up to 15-32 percent and also increasing the distance of leak from reservoir from 56.3m to 117.4m, headloss will decrease up to 10 percent. A formula is developed in this research that can calculate location and diameter of leak with 5.13% average of relative error and R2=0.94, using recorded pressure wave data that generated by sudden valve closer in pipeline with leak. The error rate calculated from the calculation of the leakage point of the water hammer valve is also 4.56%.

 Normally, for determining the coastal wave parameters, flow is considered one dimensional, and momentum and continuity equations (Saint Venant equation) is used. In order to calibrate these equations, the wave parameters need to be measured in the laboratory. As result of studying wave phenomena and wave fracture in a laboratory, momentarily recording wave characteristics is important. This urged design and construction of tools which can be more accurate for research. At present, because of being high value of the importing precision measuring equipment, major obstacle for research in many fields of hydraulic engineering in Iran was always a problem. According to prime cost and the proper performance of the system for measuring surface wave parameters in open channels (which has been tied up in real testing), there is a possible chance for all universities and research centers throughout Iran that can be equipped with reasonable & logical costs.
In the constructed device in this, the temperature sensor was used to calculate the sound speed and then measurement of the fluid's height by using ultrasonic sensors and pressure sensors. It is measured by sending pulses of ultrasonic waves and receiving reflection and calculating the amount of sweeping water for different times. These measurements are carried out in different sections using several sensors. A software was designed after the filtering of the information and omitting noise, they are determined by the wave characteristics.
The system for measuring surface wave characteristics in open channels has been registered in the form of an invention with the number 92727 dated on 2017-7-10, with the Industrial Property Office of the Iranian Patent Office.

 Abstract:
Depending on current condition in hydraulic structures of control, adjustment and measurement of the flow, porous and rigid media, would present different results which show the relevance advantages of each special condition compared to each other. Porous media gabion, is manmade and environmentally friendly which the application of this porous structure in using of required structures in water science will bring some advantages ; such as reducing of current expenses, and maintenance, speeding up the construction, preventing pollution due to waterlogging and also land harvesting in steep valleys. Depending on media conditions and basic needs in studies, the advantage of these structures is obvious compared to rigid structures. In this research, hydraulic parameters of broad crested weirs and Crested slope weirs including recharge coefficient, water surface profile, through discharge of porous media numerically were evaluated by Flow 3D software. In 42 different models including 14 different geometry of weir ( 6 broad crested and 8 Crested slope) with 3 kind of porous materials ( %46, 44 , 43) and 3 observed model, has been assessed.
The result shows that the increase in diameter of particles will enhance discharge coefficient, through flow ratio which will cause increasing of energy drop. In rectangle Weir in a constant grading, by increasing of p/lw, thorough discharge and discharge coefficient will increase. Regarding to Crested slope weir, similarly the increase in particles diameter, will simultaneously increase through discharge, flow discharge coefficient and as a result it will lead to increase of energy loss in fluid. Also with degree reduction, discharge coefficient and through flow in weir will decrease.
Slopes in upstream has higher discharge coefficient than downstream slope which demonstrate that with higher discharge coefficient, higher ratio of flow in weir cross section will pass. Also, in models with two directions, we observe that end point has more effect on surface water head than start point of it.

 During the recent years, Gabion weirs are taken into consideration due to their simple design and construction and also direct effect on river’s water quality. In this research, Hydraulic parameters of gabion crump and broad crested weirs including water surface profile, discharge coefficient and the ratio of through to total flow discharge were examined numerically using Flow-3D software. Overall, 13 geometries of weirs were examined including 7 broad crested weirs and 6 crump weirs all in 3 different porosities of (43%,44%and 46%). Results indicate that increasing in particles diameter will increases the discharge coefficient, through flow ratio and energy drop. In addition, increase in upstream and downstream slopes will decrease Cd and Qin/Qt. Also results showed that the effect of downstream slope on Cd and Qin/Qt is greater in comparison with upstream slope. Also, stream-wise and vertical velocity distribution around Gabion weirs were assessed along with the distribution of turbulence intensity. It has been showed that the turbulence intensity around weirs with smaller particles are greater in comparison with larger particles.

Coastal protection means the resistance against the waves and erosion. Since coastal areas are of the national capital and generally have strategic locations with high demographic density, protecting them from dangers of overflowing waves such as tsunamis is very important. The tsunami destructive process includes wave raising which leads to demolition, colliding with facilities and carrying items, and wave falling that drags items and people into the sea due to its high speed and is the main cause of death and heavy financial losses. There are several ways to protect the coast which are based generally on structural and non-structural methods. During different periods, due to the intrinsic advantages resulting from the use of natural protection methods, the approaches are altering from structural reinforcement to natural supporting of the shoreline. At the moment, coastal vegetation which fits in the current conservation trends is considered as a form of biological control, playing a major role in the development and protection of ecosystems. Traditional ways of protecting the coastline includes construction of firm structures such as blades, breakwaters and seawalls in order to dissipate energy and reflect waves. Coastal vegetation not only reduces tsunami overflow development, but also has further advantages such as environmental compatibility and economic efficiency. In the recent decades, there has been a growing attention on studying the effects of coastal vegetation on the sea streams, rivers, estuaries and bays. This kind of protection is a new approach in solving hydraulic and coastal engineering problems based on ecological balance of the environment. Among the important factors which controls the amount of the wave effects on coasts and coastal structures is the wave breaking condition in shallow water zones near the coast. Literature review about coastal forest operation against waves shows that the information about the exerted force on coast and direct measurement of this parameter in both with and without vegetation, especially in long waves condition is limited and requires more research to investigate the coastal vegetation effective parameters on reduction of waves destructive energy using direct measurements of trees drag force. To this purpose, the experiments were conducted in a rectangular flume located in the Physical and Hydraulic Models Laboratory of Water Structures Department of Shahid Chamran University of Ahwaz. The flume was 8.3m long, 0.8m wide and 0.55m high. The knife-edge part of the flume which can move freely in a limited range was used to measure the exerted force to the coast in presence of the vegetation by means of the installed load cell below the movable part of the flume. The knife-edge flume was 1m long which was located 4.1m away from the beginning and 3.2m away from the end of the flume. The experiments carried out on four coast slopes of zero percent (horizontal coast), 3 percent, 6 percent and 9 percent in three vegetation density of 30 percent, 50 percent and 100 percent and also in no vegetation (control test) condition, for 13 water depths on sloping coast and 9 water levels in the reservoir. 240 experiments conducted in four coast slope with three vegetation density and no vegetation condition. To be ensure about the obtained data, the experiments were repeated twice. Therefore, in this study the total number of experiments is 480. The results indicate that, by the increment of the incident wave height, the total absorbed force by the vegetation and the coast slope model in 30 percent, 50 percent and 100 percent vegetation density in different slopes in comparison to no vegetation condition increase 49 percent, 59 percent and 73 percent, respectively. Also the average increment of absorbed force by coastal trees in 30 percent, 50 percent and 100 percent vegetation density in comparison to no vegetation condition (control test) is 16 percent, 31 percent and 63 percent, respectively. In addition, in the presence of vegetation, the average increase of the absorbed force by vegetation on 3 percent, 6 percent and 9 percent coast slope in comparison to the horizontal slope, was 10 percent, 17 percent and 22 percent, respectively.

The discovery of governing lows on seas and oceans has been one of the most important issues due to the importance of the coastal areas. Waves are the most important factor in determining the geometry and composition of the coasts and also the most important factor of transfer of energy from seas and oceans to the coasts. One of the waves that compromises the security of coastal areas seriously and has brought a lot of human and financial catastrophes is tsunami that is called as one of the most divesting natural disasters. This phenomenon can be caused by earthquakes, severe volcanic eruptions, and hard bursts or even by encountering of a large body from sky to earth as a meteorite. In this study the effect of coastal green belt (tree cover) on absorbing force and its ability to dissipate wave energy is investigated. The effect of trees on wave attenuation was studied in a wave flume as length of 8.3m, 0.8m wide and 0.55m high made of Plexiglas and metal in water structure department of Shahid Chamran university of Ahvaz. To obtain the requirement data, 736 experiment conducted, with 14 water depths in front of the gate and 5 water depths behind the gate, on four slopes (horizontal slope, 3 percent slope, 6 percent and 9 percent ) with three density (30 percent, 50 percent and 100 percent). To be ensure about the measured data, the experiments were repeated twice that 144 experiments of non-breaking were related to no vegetation condition (control test) and 592 of non-breaking wave related to with vegetation condition. The high performance of vegetation is obviously clear in comparison to no vegetation condition (topography effect). For example, by increase of incoming wave height, the presence of vegetation in 100 percent, 50 percent and 30 percent density, dissipates the wave force 75.63 percent, 60.77 percent and 49.67 percent on average in comparison to no vegetation condition. Therefore, in general with increasing of incoming wave, the coast model is able to absorb 50 to 70 percent of wave force more than no vegetation condition (topography effect) that is rational justification for implementation of coastal areas, the range of absorbed force by density increment, is higher in 100 percent density in comparison with the others. The highest rate is in the 6 percent slope, where by changing the density from 50 percent to 100 percent the absorbed force increased 39.96 percent. In this case, by doubling the density the wave reduction factor increased 39.96 percent. Also by increase of density, the 100 percent, 50 percent and 30 percent density dissipate the wave force 53.56 percent, 30.78 percent and 18.65 percent respectively in comparison to no vegetation condition by increment of coast slope in presence of vegetation more wave force is absorbed, so that in 3 percent, 6 percent and 9 percent slope for all vegetation density the absorbed force increased 35.12 percent, 26.56 percent and 16.66 percent respectively on average.

 Dissipation of the kinetic energy generated at the base of a spillway is essential for bringing the flow into the downstream river to the normal condition in as short of a distance as possible. Stilling basins have various types including standard USBR basins, SAF basins and perforated basins. This research is performed in order to investigate the hydraulic performance and the effect of perforated sills in stilling basins on hydraulic jump’s characteristics. Simulations are performed using FLOW-3D software. Results of numerical simulation are calibrated with Laboratory data obtained from physical modelling. In this study, the feasability of the control of hydraulic jump in stilling basins at the presence of solid and 12%, 25%, 50% and 75% perforated sills was investigated in a rectangular fume of 2.5m length, 0.4m height and 0.15m width. In order to reach this purpose, numerical simulations were performed utilinizing the RNG turbulence model. Flow charcteristics in various status of sills compared to each other and various parameters investigated including Energy dissipation, secondary depth of hydraulic jump, the effective length of stilling basin, optimum height of perforated sill and the optimum distance of sill from the beginning of basin. Results were compared to laboratory data. Considering the numerical results, the 50% perforated sill had a better performance against other sills. Simulation errors were 11.58% for the relative height of sill, 16.3% for the optimum distance of placement from the jump’s toe, 8.36% for optimum length of basin and 8.14% for the relative energy dissipation. Velocity distribution profiles were compared in 3 sections of flow. Also the results o this study were compared to other researches and results of USBR study.

Nowadays, The importance of environmental issues, Ease in implementation, High durability, Convenient access and Economic optimization caused the Gabion Weirs to enjoy particular place compared with impermeable weirs. The physical and chemical substances such as sediments and suspended organic matter can pass Gabion weirs, downstream through the permeable body unlike general solid concrete type. Also from the viewpoint of water quality, generating turbulence in flow and promoting aeration through the air-water interface, contributes to the self purification in flow. In this study, the effect of changes in geometry and size of the materials on the hydraulic conductivity in broad crested gabion weirs is addressed. For this purpose, nine models were constructed. Eight of them represent the gabion weirs and the other one, for a solid broad crested weir similar in dimension to the gabion weir(Length:15, Heigth:15), is used to compare the results of the gabion weir with solid weir. The gabion weir was fabricated from steel rods rapped with a grid sheet with an opening less than the size of the filling material to form the gabion basket then filled with gravel material.
In free flow conditions the results show that, in all models, With increasing crest length, the discharge coefficient decreases. Also, with increasing the material size, the discharge coefficient increases and the water head decreases. For the same discharge, the water head over the gabion weirs is always less than the impermeable weirs.
Also in submerged flow conditions the results show that the submerged flow rate reduction factor (ѱ) (in compared with y2 / y1), depending on the increase of (y2 / y1), decreases in all gabion models. Also for a constant ratio of (y2 / y1), With increasing crest length, the rate reduction factor (ѱ) increases. Note that, in general, the material size have no significant effect on the rate reduction factor(ѱ).
In this study, according to conducted dimensional analysis of the results, the empirical equations are obtained for estimation of the free flow discharge coefficient and the discharge reduction factor(ѱ) due to submergence.
 

Weirs are among the important hydraulic structures to control the flow, regulate the water level in the upstream and measurement flow in channels, rivers and irrigation networks. Weirs are usually constructed by concrete and are impervious. Such an impervious barriers prevent normal convey of aquatic-life and suspended materials and hence has negative impact on eco-system. In order to overcome these negative impacts, researchers newly proposed to use cheap natural materials for construction of weirs. In this between, Gabion weirs with instinctive characteristics including stability, conductivity and economic justification are strongly advised. Gabion weirs in terms of materials, form and function more compatible with the surrounding nature, so they are valuable from an ecological point of view. This research investigated hydraulics effect of weir crest slope of gabion broad-crested weir. For this purpose 9 different Gabion weirs with different weir crest slopes models and one impermeable weirs model in a horizontal flume were examined, i.e., length, width and height equal to 15, 0.3, 0.5 m respectively. This test was utilized for wide range of parameters, including: discharge, upstream and downstream depth, material size and different crest slopes.in free flow condition Result shows, in all models, and changes in the upstream crest slope have greatest impact on the discharge coefficient. Also, with increasing the material size, discharge coefficient increase and water head decrease. In gabion weirs incipient submergence occurs between in proportion 0.42-0.75. The submerged flow rate reduction factor (φ) to y2 / y1 depends on the increase of y2 / y1 decreases. Finally, According to conducted dimensional analysis of the results provided empirical equations for estimation of free flow discharge coefficient, incipient submergence flow coefficient, and discharge reduction factor due to submergence.

 Weirs are usually constructed by concrete and are impervious so that the water can only flow above the crest. Such an impervious barriers prevent normal convey of aquatic-life and suspended materials and hence has negative impact on eco-system. In order to overcome these negative impacts, researchers newly proposed to use cheap natural materials for construction of weirs. In this between, Gabion weirs with instinctive characteristics including stability, conductivity and economic justification are strongly advised. This research investigated hydraulics of flow over crumps Gabion weirs. For this purpose, eight Gabion weirs and three impervious weirs have been set up in a 15m long, 0.3m wide and 0.5m deep channel. Experiments have been performed with variable discharge, downstream depth, upstream slope, downstream slope and rock materials. Results showed that discharge coefficient of crump Gabion weir is greater than impervious crump weir and flow coefficient increases as the rock diameter increases. In other word, for same discharge past the weir, water head on a Gabion weir is less than the head on an impervious weir. In a crump gabion weir, increase of rock diameter increases the flow, and increase of the weir slope upstream and downstream sides delay the incipient submergence. A non-linear regression analysis of the results provided empirical equations for estimation of free flow discharge coefficient, incipient submergence flow coefficient, and discharge reduction factor due to submergence.

Total inspectors to calculate the flow rate, velocity and flow depth in the natural channels and also estimation of flood and sediment evaluation of flow resistance is important and necessary.
Hydraulic resistance in open channels is an important characteristic of the surface flows. That properly is important for runoff modeling, flood routing, inundation and erosion.
Surface resistance can measured by number of hydraulic roughness coefficients such as Manning coefficient(n), Chezy resistance factor(c) and Darsy-Vysbakh resistance factor(f). In this study investigated the effect of hydraulic parameters such as depth and velocity on this coefficients in the mountain shallow waters.
As well as assumption that based and start of the study is significance of surface tension the simplified equations of Navyr-Astvks(N-V) to the equations of Saint-Venant(S-V) on the surface shallow waters. The experiment measured the depth, changes in physical modeling of 3 sloping 20, 30 and 35% , in the 4 roughness in smooth surface as control and roughnesses of 1, 1/5 and 2 mm, in 5 discharge with sizez 0/8, 1/6, 2/4, 3/2 and 4 liters per second, with a total of 60 tests were repeated 3 times to 180 tests were performed on a grid of 16 points.
After testing, according to available data, the results showed that the flow created with Reynolds numbers greater than 2500 flow resistance significantly affect the dimensionless Froude number. However in laminar flows with lower Reynolds numbers these effects are but in this range of Reynolds effect is more pronounced. Also with hydraulic parameters available such as depth and velocity are shown at a constant flow rate with increasing roughness size, depth increases and velocity decreases. Chezy resistance coefficient increases with increase in Froude number (increase rate), but the size of the roughness does not have a significant effect. Darsy-Vysbakh coefficient(f) decreased with increasing Froude number, and changes in the size of the roughness does not cause significant changes. Manning roughness coefficient(n) has an inverse relationship with Froude number and a direct relationship with the size of roughness. About the effect of slope, according to graph obtained with the increase in the slope speed increased which indirectly affects the flow resistance. According to one of the three original Novak theory can be said based on available data surface tension can be important in the equations however more studies are needed for more definitive result.
 

Limited water resources and Enormous costs of providing, Transmission and water distribution, will enhance the Optimal operation of reservoir systems in the country.In this context, An efficient management and Proper utilization of available resources is so important. In courses of water shortage in this study, the optimization of dez dam reservoir operation has been done with two purposes: first, minimizing the difference between release and water demand. Second, obtaining maximum energy to produce optimal rule curve.For this purpose, A computer program has been written in Visual Basic for deterministic dynamic programming.Due to the effects of removing surface and groundwater upstream on the rate of inflow to the dam, the historical time series will become natural, and then by subtracting the current removal, the Inflow to the Dez dam will be forecasted; the input file would be created, and at last the results would be shown for various positions.The result suggests that due to long-term changes in inflow to the dam as a parameter which is influencing and changing the needs of downstream, optimal rule curve of the dam is subject to change. Thus, through examining different modes of input flow rates for wet and dry years and also different needs of downstream, the results showed that, according to the reservoir volume change because of sediment and changes in the inflow , the original dam rule curve could be no more optimal.Also changes in downstream requirements, will result in changes in the operation of dam Optimal rule curve.