فصلنامه علوم و مهندسی آبیاری
سال سی و هشتم شماره 3 (پاییز 1394)

Groynes structures are among effective and common hydraulic structures for bank protection along bends. In the present paper, the effects of series of groynes along a 90 degree mild bend on flow characteristics such as flow and shear stresses distribution have been investigated. Tests were carried out in a bend flume having 0.7 m width, the R/B ratio for the channel bend is 4 and depth of flow for all test kept constant 0.14 m. Groynes were non-submerged and they have been used in three different lengths which are 15, 20 and 25% of channel width and three different angles including 60, 90 and 120 degrees. Also the distance between spurs was equal to 3 times of their length. The analysis of data showed that the high velocity zone moves toward center of channel and inner wall. The relative shear stresses were significantly increased by increasing the length of spure dikes and theirs elongation causes the relative shear stress multiplication up to 6 times. However, the length and angle of spurs have not had significant effect on the position of the maximum relative shear stresses along the bend. Nevertheless, the maximum relative shear stresses happened in a cross section between 70 to 80 degrees of the bend (almost end of the bend) for all experiments.

Water deficit is the prime limiting factor in soybean production in semi-arid regions. Therefore, increasing soybean seed yield requires the selection of resistant and adapted cultivars to dry or water deficit conditions of Iran. In order to evaluate the effect of irrigation regimes on seed yield and yield components of three soybean cultivars an experiment was conducted in Lorestan University of Technology Research farm during the growing season of 2010-2011. The experiment was arranged as split-plot in the form of completed block design. Irrigation regimes were the main plots and the subplots were three soybean cultivars (M7,M9 and TMS). Then, irrigation treatments were conducted as follow; CI: applied 100% of water requirements during the whole season and RDI80, RDI70 and RDI50 applied 80%, 70% and 50% of water requirements, respectively. Based on the findings of this study, deficit irrigation had significant effect on the number of nodes, plant height, number of pods per plant, 100 seeds weight, grain yield and biological yield. Severe stress conditions had maximum effect on reduction in nodes number (10.54), plant height (44.24 cm), number of pods per plant (24.5), grain yield (1259.9 kg.ha-1), biological yield (3013.2 kg.ha-1) and 100 seeds weight (11.77 g). M9 cultivar had the most yield, biological yield, number of pods per plant, number of nodes, 100 seeds weight and water productivity in the water stress condition and non-water stress condition among the studies cultivars.

Huge amount of drainwater is disposing of operating Irrigation and drainage networks in Khuzestan, SW Iran, that needs to manage. One of the low risk manners of reusing drainwater is use it for saline land reclamation. To investigate the effects of leaching methods and water quality on desalinization of clay soils of this area, leaching experiments were done in 1.5×1.5 meter Plots in “Salman Farsi” sugarcane agro industry, South Khuzestan. Complete combination of three different water qualities; 2.7 dS/m (fresh water from Karun River), 6.0 and 9.0 dS/m (mixture of agro industries drainwater and Karun River water) and tow leaching method; continuous (application of 120cm of water) and intermitting (application of four 30 cm of water with five days interruptions) in six treatments and three replications based on complete randomized blocks design were experimented. Results shown that using drainwater with the quality of 6.0 or 9.0 dS/m could reduce the use of fresh water for desalinization by intermitting leaching up to 72 or 51 percent, respectively. The difference between soil saturation extracts due to applying different water qualities were more in deeper soil layers, also the difference between continuous and intermittent leaching were increase by applying more saline water. In heavy soil, advantage of intermitting leaching method to continuous one is limited to low evaporation condition.

Triangular weirs (Triangular vanes) and footing are measures which causes to control the scour in outer bend and keep out scouring hole from the outer bend. In this study, the main purpose is to experimentally study the effect of using both footing and triangular weirs on sedimentation and erosion of a bed of flume bend under different flow conditions (Froude numbers 0.243, 0.262, 0.292 and 0.321). Tests were conducted using triangular weirs with distance of 8 times of the effective length installed at an angle of 30 degree from the upstream bank. Footing width and effective length of triangular weirs were selected one-fifth the width of the canal. The results showed that using footing combined with the triangular weirs caused to reduce maximum scour depth at the toe of weirs and prevent from its extension to outer bend. Using footing reduced 70 percent maximum scour depth at the toe of weirs. Moreover using footing combined with triangular weirs had a little effect on flow diversion from outer bank towards the center of flume. The results show that using footing along with triangular weirs increased 9 percent maximum scour depth of thalweg and did not change the thalweg distance from the outer bank.

One way to decreases the damage caused by cavitation in spillways is aeration flow using aerators. The required air flow of aerator is one of the most important factors in their design. In this study, to estimate the required air flow of spillway aerators four methods were applied including of stepwise regression, Pfister empirical method, neural network (based on Levenberg- Marquardt algorithm) and the combination of fuzzy-neural (ANFIS). In order to perform of modeling, 914 experimental data on physical model of Clyde Dam spillway and 12 data of Azad Dam related to conducted tests by Water Research Center on Azad dam hydraulic model were gathered. However, the performance and error of these methods were investigated after calculating the required air flow of aerators. The results showed that the combination of fuzzy-neural has the best performance with a root mean square error (RMSE) and correlation coefficient (R) about 0.0194 and 0.968, respectively. In addition, artificial neural network, stepwise regression and Pfister empirical methods had a root mean square error equal to 0.0538, 0.0596 and 1.98, respectively.

In this paper presented the evaluation of particle swarm optimization for solving complex optimization water resources problems. The main problem with PSO is it’s prematurity. Therefore a new adjustable PSO-GA hybrid algorithm which combines PSO with genetic operators was proposed. The basis behind this is that such a hybrid approach is expected to have merits of PSO with those of GA. The main idea of GA is due to its genetic operators crossover and mutation. By applying crossover operation, information can be swapped between two particles to have the ability of flying to the new search area. The purpose of applying mutation to PSO is to increase the diversity of the population. For evaluating of the proposed algorithm the optimization of the hydropower operation of ‘‘Dez” single reservoir has been studied. The results of HPSOGA compare to PSO and GA indicated the proposed algorithm increases the flexibility and capability of PSO to generate strong-developing individuals that can achieve faster convergence rate to optimum point and it is very useful in solving optimization operation water resources.

In order to study the chemical clogging and its effect on hydraulic performance of trickle irrigation system, four treatments includes compensating emitters (Netafim and Micro-Flapper), non-compensating emitters (Mehr and Goldani), three treatment of flow rates that includes 8, 4 and 2 lph (liters per hour) were selected and tested using Karoun river’s water in No. 1 research farm of Shahid Chamran University of Ahvaz. The experiment was conducted in a Completely Randomized Block Design (CRBD) and irrigation was performed in 31 times with irrigation frequency for two days, at pressure of 1.5 bar. The results showed that decreasing of flow rate of Micro-Flapper emitter with 8 and 4 LPH flows is higher than the other treatments and this decreasing is significante at the five percent. Also the Micro-Flapper emitter with 2 lph flows has the lowest decreasing of flow rate. Based on field observations, herniation of silicon diaphragm that used in Micro-Flapper emitters with 8 and 4 lph flows is the main reason for the reduction of flow rate and high values of CV, qvar and qd. So in this particular case the Chemical sediment did not impose a major effect. Turbulent regime of water at the outlet is the reason of resistance against the chemical clogging in the Micro-Flapper emitter with 2 lph flows. In Netafim emitter with 8 and 4 lph, despite having the significant clogging in five percent signification level have a minimal values of CV, qvar and qd and high values of EU and CU. In this experiments, the treatment which had the lowest coefficient of manufacturing Variation, was accounted to it the lowest coefficient of variation of flow rate and the highest Emission Uniformity of variation. In most treatments during the Irrigation, values of CV, qvar and qd increased and values of EU and CU decreased. According to the results presented, the Goldani emitter with 8 gph flows is rated and selected as the top emitter in both terms of resistance against the chemical clogging and hydraulic performance parameters than other emitters.

One of the natural disasters that annually causes a lot of damage to people and society, is flood.Timely flood warning system to ensure that final beneficiaries forecasting system, an appropriate warning is received at the appropriate time and the appropriate response to protect and minimize the damage done to their finances.In this regard, Gharanghoochay river catchment, causing massive floods in Mianeh city has been selected to implement a flood warning system. In this paper, hydrological modeling for the basin using HEC-HMS software was obtained and for the entire sub- basin, Muskingum dynamics equations have been used. The flood located in east Azerbaijan province, floods 2004.06.03 calibrate the model rainfall - runoff flood warning was used. Continuity check with showers and amount of time before the alarm warning signal for each station was calculated. After pre-determined according to abundance of caution showers Hashtrood station, flood warning systems for flooding areas within the mat-o-flood plan has been designed to suit the threshold. Under-taking damage riverbank villages and history of natural disasters in the region and assess the damages incurred to the Mianeh city, emergency action guidelines was prepared.

In order to estimate the amount of bacterial contamination in a soil (silty clay loam) treated with poultry manure, the mobility of E.coli bacteria was simulated using inverse modeling. The E.coli was selected for this study since it presents as a pathogenic bacteria in poultry manure. For this purpose, two equilibrium (CDE) and non-equilibrium equations (NECDE) were numerically solved using HYDRUS-1D code and inversely calibrated with a laboratory experiment data. The NECDE equation could predict E.Coli mobility through the soil with more accuracy both in calibration and testing steps than CDE equation. The coefficient of determinations for NECDE and CDE equations were 0.99 and 0.91 for calibration step, and 0.97 and 0.98 for validating step, respectively. Therefore, NECDE equation with using inverse modeling could be a reliable equation for simulating E.Coli transport through the soil.

Increasing population and demand for water resources caused to evaluation water quality and manage water resources unavoidable. In Urmia plain water quality and quantity is confronted with critical condition. The purpose of this research is to zone the groundwater quality in Urmia plain for potation consumptions by AHP model and GIS technique. To achieve these purposes, the data of 128 deep wells from 2011 to 2012 was used. In the beginning, raster maps of studied region were provided with different methods of interpolation. In attention to wells distribution in the plain the Kriging method was used to zone maps of Sodium, Chlorine, Sulfate, Total dissolved solids, total hardness and electrical conductivity. Based on Schuler diagram and using analytical hierarchy process, the most efficient weights for each hydro-chemical variables were selected. Finally with overlapping hydro-chemical layers and exerting definitive weights in geographic information system, groundwater qualitative potential map in the studied region for determining the suitable places for drinkingwater was provided. The results showed that among five defined potential region, 78.4% of studied region is in good up to acceptable range, 7.7% is in inappropriate range, 12.9% is in bad range and 1% is in potable in necessary times. Entirely, central, south, northeast and northwest parts of studied region have best quality of groundwater for drinking consumptions.

Runoff simulation is a challenging issue in ungagged basins with missing data. Therefore hydrological modeling involved with new automatic calibration methods should be considered seriously. Since adjusting the models with high parameters manually is a time-consuming and labor-intensive task, automatic calibration techniques are generally required to obtain reasonable estimates of the model parameters. Thus in this research we aim to compare and assess calibrating of a conceptual daily rainfall-runoff model (Hymod) with five global optimization methods (GOMs). As well, two case studies (Karaj and Leaf Rivers) were selected to assess and present the results adopted from runoff modeling with two forcing data, rainfall and evapotranspiration series. A new performance criteria, KGE as a new criterion is decomposition of the widely used Nash–Sutcliffe efficiency (NSE) was applied in this study to analyse the different components that constitute NSE. Results revealed that particle swarm optimization (PSO) and shuffle complex evolution (SCE) may be more efficient and robust significantly and will be able to simulate daily runoff with better performance criteria.

Determination of water distribution uniformity of coefficient of sprinkler irrigation based on data of a single sprinkler is time consuming due to overlapsprinkling by neighboring sprinklers and also different pressure heads, riser heads, sprinkler gaps on laterals and the distance between laterals. The best combination of the mentioned parameters to achieve maximum water distribution uniformity of coefficient, is still unknown question for applicators. In this research, water distribution uniformity of coefficient of ZB model sprinkler (made in Iran) were measured at Hashemabad cotton research station of Gorgan under 3 different pressure heads (2.5, 3 and 3.5 atm), two riser heads (60 and 100 cm) and seven sprinkler (Sl×Sm including 9×12, 9×15, 12×12, 15×12, 12×18, 15×15, 15×18m) arrangements. Two different algorithms namely PSO and GA were developed in MATLAB to determine water distribution uniformity of coefficient parameters with respect to mentioned parameters. based on statistical parameters such as coefficient of determination (R2), root mean square error (RMSE) and also standard deviation (SD) the performance of these algorithms were investigated. The results show that both of them can accurately predict water distribution uniformity of coefficient and therefore they can be used in determination of water distribution uniformity of coefficient.

Due to environmental considerations, using permeable control structures in rivers have been widely welcomed by engineers working on different aspects of rivers. Impermeable structures such as rockfill dams could provide more suitable hydraulic conditions for flow discharge within rivers by allowing sediments pass through their body so that the environmental impacts at structures downstream may be reduced to its lowest rate. Although there are a large number of researches carried out on the hydraulics behavior of the flow passing through fine and coarse materials, there is, however, a few studies on passing bed load through dam body of rockfill structures. In this experimental research, to provide suitable condition for bed load to pass through dam body, a coarser layer of materials has been used at the bottom of the dam. Using dimensional analysis and data provided from laboratory tests, a relationship to estimate the amount of bed load passing from coarse materials has been introduced, and in this regard, the available equations to estimate bed loads, are modified as well. The mean relative error of the new equation was estimated as 64.7% while it is estimated as 101% for Meyer- Peter and Muler modified relationship. Furthermore, it is found that at the range of the experiments carried out in this research, using coarser materials at the bottom of rockfill dams has no significant effects on the amount of bed load passing through dam body.

The aim of this study is the investigation of nitrate removal from aqueous solution using quartz sand – supported zero valent iron nano particles (Sa-Fe0). The synthesis of Sa-Fe0 was based on the reduction of ferrous iron with borohydride, in which quartz sand acted as a porous-based support material. The structure of adsorbent was characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Brunauer–Emmett–Teller (BET-N2) analysis. The SEM images revealed that nano zero valent iron particles (nZVI) immobilized on Sa-Fe0 were spherical and clearly discrete and uniformly dispersed on the surface of the stabilizer without any obvious aggregation. In the batch mode adsorption studies, the effects of the contact time, initial nitrate concentration of solution, sorbent dosage,temperature and initial pH on the nitrate adsorption by the Sa-Fe0 have been studied. The adsorption capacity decreased with increasing the Sa-Fe0 dosage and initial pH value of the solution but increased with the increase in the temperature and initial concentration of nitrate. Removal of nitrate using Sa-Fe0 was in accordance with the pseudo first order kinetic model. The initial phase with the rapid rise of the adsorption rate was about 8h and the removal efficincy in this time interval was about 85% for the initial nitrate concentrations of 100 mg/L. The equilibrium data fitted well to the Langmuir model. The maximum adsorption capacity of Sa-Fe0 for nitrate was 20.833.