Iranian Water Research Journal

Abstract Agricultural water productivity is an important concept for water and food managers on large scale, and caused to developing remote sensing technique on several last decades. This research was done on Qazvin irrigation network and was estimated evapotranspiration and dry biomass by using SEBAL algorithm on four MODIS and AVHRR cloudless images. Pre-processing and processing on images were done by ENVI and ILWIS models. The estimations of SEBAL were compared with lysimeter data which comparison results on MODIS and AVHRR showed correlation coefficient 0.92 and 0.81, respectively. Finally, SEBAL produced better evapotranspiration and water productivity estimations when MODIS has been used. Average of wheat water productivity amount measured 0.76 kg/m³ by lysimtere and this amount were estimated 1.03 kg/m³ by MODIS and 0.9 kg/m³ by AVHRR images.

Abstract Studying intra and inter variations of runoff and sediment on storm basis facilitates understanding problems in a watershed. However, such studies have been fortuitously conducted. Accordingly, this study was planned to evaluate intra and inter variations in runoff and sediment on storm event basis in plot scale with dimension of 50×50 cm in rangeland and reclaimed forest treatments with three replications at Kodir village in Alborz Central mountain range. For this study, a pumped rainfall simulator with 5 liters volume capacity, intensity of about 1 mm/min and drops diameter of 1 mm and similar to prevailing precipitation conditions in the study area for a period of about 22  min was used. The amount of runoff and sediment at the onset of starting runoff generation were collected at every 2 min from April 2009 to May 2010. The results of the study showed that the trend of runoff within events in both range and revived forest use was initially increasing and then decreasing. Sediment variation with further fluctuations was found similar to that of runoff. The amount of runoff and sediment in the rangeland use was 3.8 and 7.7 times more than those recorded for reclaimed forest use. Also, the highest and the least amount of runoff in both uses occurred in April 2009 and September 2010, respectively, while the highest and the least amount of sediment occurred in February

Abstract In this article, a numerical model has been developed for ?D numerical modeling of dam break flow. The model approximates the depth-averaged, shallow water equations with a finite volume, implicit, semi-Lagrangian representation and a semi-analytical method have been used to determine incipient motion of particles. To demonstrate the accuracy of proposed method, the results obtained by this model for a dam break problem of one-dimensional flow were compared with the corresponding analytical results, and the solutions obtained from two-dimensional flow with the experimental tests. the comparison showed that numerical model is stable, even for the Courant numbers higher than unit. Also a good agreement between experimental data and computed values (sum of normalized errors of model about 0.3) showed that for the Courant number below 1.4, even in range in which hypothesis of shallow water are not true, the developed model is validated.

Abstract There is a growing tendency to assess the safety levels of existing dams based on risk and uncertainty analysis using mathematical and statistical methods. This research presents the process and application of risk and uncertainty analysis to dam overtopping and applies a probability-based methodology to evaluate the probability of earth dam overtopping. A flood frequency analysis of 32-year annual maximum discharge was carried out by applying General Extreme Values (GEV) distribution for the Doroudzan reservoir in the south of Iran. The procedure includes univariate flood and wind speed frequency analysis, reservoir routing, and integration of wind set-up and run-up to calculate the reservoir water elevation. The highest water levels in the reservoir were computed by using the reservoir routing technique and considering the quantile of flood peak discharge, initial depth of water in the reservoir, and spillway discharge coefficient as uncertain variables. Afterward, the probability of overtopping due to flood and combination of flood and wind speed for return periods of 50, 20, 10, 2, 100 years and 4 different water levels were evaluation by applying Monte Carlo simulation and Latin hypercube sampling.

Abstract The present study investigates the climate change effect in future time periods in Kermanshah station in west of Iran. The daily precipitation and maximum and minimum temperature data were downscaled by LARS-WG downscaling model. Weather data were estimated based on NCCCSM global circulation model and by A1B, A2, and B1 scenarios in three time periods: 2011-2030, 2046-2065, and 2080-2099. The climate indices used in the study include Johansson Continentality Index, Kerner Oceanity Index, De Martonne Aridity Index, and Pinna Combinative Index. Comparing the results of the four indexes in the base time period and the future ones indicates that the area climate will approach aridity. The aridity of the area is more severe in A2 scenario than the other two scenarios. According to the precipitation-temperature diagram of the area May will get dry gradually, and April also, will approach dry conditions.

Abstract Regarding the poor performance of distribution canals in irrigation networks, offering effective methods to improve performance and optimal operation is considered necessary. Water distribution and delivery scheduling is a complex, multi- objective, multi- variable, and multi- constraint problem, which requires powerful optimization methods to be solved. In this study, ACS Algorithm is used for solving water delivery problem in AMX canal of Varamin irrigation network with 11 intakes. Three irrigation blocks were considered for temporal distribution of water delivery intakes. Intake classification in the blocks and scheduling of water delivery was determined so that intake demand water in irrigation duration is delivered by minimum of canal capacity. Based on research results, the maximum canal capacity achieved 1.15 m³/s. compared to PSO, the canal capacity was 490 l/s less than ACS. Also, the number of upstream gate regulations obtained 1 regulation less than PSO method. Results indicates the preferably of ACS method to PSO method.

Abstract Water is a key index for development of a region. Due to limitation of financial resources and opportunities, ranking of projects is essential and multi criteria subjects. In this study the optimal ranking of nine projects of dam establishment in Chaharmahal and Bakhtiari province was carried out and the eleven qualitative and quantitative criteria were considered. For this purpose, two softwares, ELECTRE III and Expert choice, were applied. Since quantitative of qualitative results of the sensitivity analysis of the decision making methods has not been considered till now the use of changes Percentage parameter came to account.In this study the sensitivity analysis of the methods used to determine changes in decision making matrix and parameters for each method were quantified. The results showed that the most appropriate of the methods is ELECTRE III because it has less sensitivity to changes in ranking. Also the results showed that the model is very sensitive to eliminate the economic criteria(B/C: about 7.07%), meanwhile it is not sensitive to eliminate the dam height, employment and population concentration criteria.

Abstract Determining future water consumption of cities and planning proper capacity for municipal water supply system (transfer network and purification complexes) revealed the importance of applying behavioral models and forecasting water consumptions in cities. Establishment of public and private administrations and big industries in Tehran's and encompassing trade and political centers beside population growth, showed the necessity of reconstructing municipal water infrastructures. Present study applied SARIMA model for modeling and forecasting municipal water consumption of Tehran city. Hence, using monthly time series of Tehran municipal water consumption during April 1998 till March 2010, seasonal unit root test was applied. Results showed all non-seasonal and seasonal unit roots exist in mentioned monthly time series. Therefore by choosing proper filter, fitting SARIMA models was considered. Considering the mean error of 2.32 percentages and high forecasting power of this model, forecasting municipal water consumption of Tehran city for 2011 could provide constructive results for municipal managers.

Abstract The most important indicators of environmental changes are meanders. For the first times, this study was carried out investigation of sealing degree and morphology changes of meander in Karoon River using TM and ETM+ instruments images of Landsat satellite and remote sensing in 1989 and 2005. In this research, morphological parameters of 20 meanders were determined at 128 km of Karoon River in two mentioned years. The results of t student test showed that sealing degrees have a significant difference at 1% level in years 1989 and 2005. The multiple linear regressions were used for the sealing degree changes and some meander parameters changes. The modeling results showed that the meander length (L) have reduces, if sealing degree changed. Also, the results of Spearman correlation showed that sealing degree and meander shape correlated strongly. Therefore, there are significant correlations between changes of sealing degree and meander shape in the level of 1 percent. By increasing the sealing degree, the meander shape changed to U and Ω shapes and meander tended to be closed.

Abstract In this study, the characteristics of hydraulic jump in a rectangular flume with sill on horizontal and adverse slope were investigated. Totally 84 experiments were performed using three different values of sill heights (s) and two adverse bed slopes of 1 and 1.5% at Froude numbers ranging from 4.6 to 7.4 The results indicated that, sill decreases the length of the hydraulic jump 6.3 percent on horizontal bed slope and 46.6 percent on adverse bed slope of 1.5percent. Totally, Presence of a sill in stilling basin stabilizes the jump on adverse slope and improves hydraulic jump characteristics

Abstract Random variables are the major reasons for uncertainty in flood modeling. Storm pattern is the most important random variable among the other variables in modeling of flood variability. Storm pattern include duration, depth and time distribution in a storm event. Accurate identification and uncertainty analysis of the effective variables on storm pattern and uncertainty analysis of storm pattern is useful for uncertainty analysis of flood modeling. In this study, combination of the rain data processor model (RDP) and the rain pattern generator model (RPG) models were used for identification and evaluation the variables affecting the rainfall patterns. Furthermore, random properties of storm pattern are evaluated in Seymareh catchment and various storm patterns were generated with acceptable accuracy. The results indicated that the RPG model has a good accuracy in hyetograph generation. Moreover, the comparison of sharpness index of Seymareh data revealed that rainfalls with less rainfall depth and long duration had less uncertainty.

Abstract Optimal allocation of water resources by using mathematical programming models has been considered in the recent years. Uncertainty is one of the important and fundamental factors in the modeling of these type of problems. The present study develops a model for optimal allocation of water in Nekooabad irrigation network in Esfahan province established in 2012- 2014. In order to considering the uncertainty, the Interval- Parameter Programming (IPP) and Two- Step Infinite ∝- Cuts Fuzzy Linear Programming (TSIFP) were used. The results showed that as increasing degree of conservatism against uncertainty (used of TSIFP instead of IPP), the middle bound of gross margin benefit reduced from 3724.5 to 3565 billion Rials (4.3 percent) for delivering water in the years of planning horizon. Finally, using the allocation model presented in TSIFP to approach the more protection of the system against losses, due to the lake of uncertainty for water availability, is recommended. To compensate loss of gross benefit of farmers in this recommended pattern, efficiency enhancement policies emphasized. Also, benefit of old structures of Nekooabad irrigation network in the area of Falavarjan and Najafabad, with the highest value of allocation of water, to reduce waste water in this network is recommended.

Abstract Nowadays, mathematical modeling is increasingly used in order to evaluate the spatial and temporal changes of the concentrations of water quality parameters in rivers and reservoirs. In this research, the FASTER model was used for water quality modeling. For simulation of the hydrodynamic conditions of flow, continuity and momentum equations (known as Saint-Venant equations), are numerically solved using the Crank-Nicholson central scheme with a staggered method and varying grid size. The Advection Dispersion Equation (ADE) has been solved using the finite volume technique. According to the available data, the parameters of nitrogen and dissolved oxygen (DO) for a reach of Karkheh River between Paye-Pole and Hamidiyeh stations were analyzed and simulated and Abdel khan hydrometric station was selected as a survey station. For solving the hydrodynamics of flow, it is necessary that Manning roughness coefficient (n) be calibrated in FASTER model. With adjusting of this factor, value of 0.028 was chosen. In this study 4 Dispersion Coefficients (DL), including Fischer et al, Seo and cheong, Kashefipour and Kashefipour and Falconer equations were used. Comparison of the measured nitrogen and dissolved oxygen concentrations and the corresponding model results showed that the Fischer dispersion model and Kashefipour-Falconer dispersion model performed relatively well for nitrogen and dissolved oxygen, respectively. Also according to the concentrations of water quality parameters that have been evaluated in this specified reach of Karkheh River, the concentration

Abstract The behavior of transport and deposition of cohesive sediments due to electromagnetic and physico- chemical properties of the sediment particles study on is too complexed. One of the important parameters involve in the processes of the cohesive sediments transport is threshold of flow shear stress for deposition. In this research a kind of clay- silty sediment obtained from an embankment dam reservoir near Shahrekord was used. All experiments were carried out in rotating flume model and for this purpose, flow velocity and shear stress in the flume was measured using Acoustic Doppler Velocimeter (ADV). The results showed that the threshold of the shear stress for fully starting of cohesive sediment deposition and critical shear stress obtained to be 1.01 N/m² and 0.038 N/m², respectively. Finally relationships were derived for calculate the shear stress threshold, equilibrium concentration of sediments and the deposition rate.

Abstract Advancement of technology in construction of structure caused to design modern type of bridge piers including inclined bridge piers group. Due to importance of identifying effective mechanisms of scour around this type of bridge piers, in this research the effect of flow parameter and level of bridge foundation on the scour depth was investigated. Bridge piers group included two inclined rectangular piers of 2.5cm width and 3.5cm length which installed at the angle of 28 degree on the top of rectangular foundation of 10cm width and 16cm length. Experiments were performed for various relative velocities, depth of flow and relative top level of the foundation from the channel bed (Z/D*) -1 up to 1. The results showed that the velocity of flow has more effect on the local scour depth in comparison of the flow depth. Comparison of results for different levels of the foundation showed that level of the foundation has significant effect on the scour depth. A maximum and a minimum scour occurred for relative foundation level 1 and -0.5. Furthermore, except of relative foundation -0.5, the scour at the inclined bridge level is more than individual pier.

Abstract Many devices and methods are available for the measurement and control of flow rate in open irrigation channels. Among, these devices, sharp crested weirs and sluice gates are commonly used. In order to minimize the disadvantages of weir and gate, they can be combined together in one device yielding a simultaneous flow over the weir and below the gate. In this study the hydraulic characteristics of combined device of weir-gate such as coefficient of discharge and effective parameter on simultaneous discharge were investigated. The relationship between the experimental and theoretical results of the geometric and hydraulic parameters in the function of the flow statistically was analyzed and a coefficient discharge for combinational flow was presented. The error from the application of equation for 95% of data was ±2.5 percent.

Abstract In this paper, the status of groundwater hydrology and hydrogeology plain of Varzaneh was studied. In the hydrology section, the annual average of Zayandehrood river flow in stations of Varzaneh and Cham was investigated. The unit hydrograph of the plain was also illustrated. In hydrogeology section, the software of RockWorks Ver.15 was used and log of wells and also the geological model of Varzaneh plain were prepared according to the logs and material of their layers. The contours lines of underground water level in unconfined and confined aquifer in the Varzaneh plain were drawn using Surfer Ver.10 software. Also the hydraulic gradient for groundwater flow in the plain area was found. The maximum value of hydraulic gradient was 0.008 from center of plain to the South East. In the past decade, the ten-years unit hydrograph of plain showed that the amount of underground water level was dropped by 1.3 meters, i.e. which the mean of annual loss was 13 centimeters.

Abstract The Muskingum model is a hydrologic flood routing method in which the accuracy of its parameter estimation affects the routed hydrograph, especially in the value of the peak flow flood. Meta-heuristic algorithms are good candidates to determine optimal/near-optimal parameters in the Muskingum model. In this paper, shuffled frog leaping algorithm (SFLA) was applied and compared in two benchmark and real case studies.The sum of the squared deviation (SSQ) between observed and routed outflows and the sum of the absolute value of deviation (SAD) between observed and routed outflow as the objective functions (DPO) as an important parameter on the routed flood hydrograph. Results show were considered that the SFLA improves (decreases) the SSQ and SAD by 0.03 and 0.40 percent in the benchmark problem, and by 3.67 and 0.27 percent in the real case study, respectively, compared to reported results using various optimization algorithms. In addition, the SFLA improves (decreases) the DPO of the routed hydrograph in the benchmark and real problem by 17.65 and 3.67 percent compared to the best (minimum) reported result.

Abstract Drought is a natural phenomenon that starts slowly and spread equanimity and traces severily on all human activities. Therefore, complete recognition and exact monitoring of drought can provide appropriate tools for dealing with it and decreasing damaging effects. One of the strategic areas that are very important in terms of agriculture is Khuzestan province. This province is very remarkable due to its permanent rivers, flood-prone rivers also various reservoirs. The main objective of this study is to improve drought monitoring by finding dependencies between drought and several oceanic and climatic parameters in different approach in comparison with statistical correlations. In this research used Data Mining Techniques of Association Rules. Drought events were determined according to Standard Precipitation Index (SPI) and its Dependencies were surveyed using oceanic- climatic indices such as Southern Oscillation Index (SOI), Pacific/North American (PNA) Index, Multivariate ENSO Index (MEI), Pacific Decadal Oscillation (PDO) Index and North Atlantic Oscillation (NAO). Results showed that the classes of selected patterns which are dominant on drought are similar in different time delays. It means that drought events are compeer with normal status of indices and are predictable with maximum and minimum accuracy 74.24 and 44.86 percent, respectively. Therefore, these rules can use as a supplement to existing approaches for drought monitoring.

Abstract The lip angle of submerged roller bucket as the main design parameter, has an effective role in energy dissipation and scour downstream of this structure. The purpose of this study is the investigation of bucket lip angle influence on the scour process and determining the best lip angle and presentation non-linear regression equations to estimate the scour dimensions downstream of submerged roller bucket. Therefore, 64 tests were conducted in different hydraulic conditions on four experimental models with different lip angles 30, 35, 40, 45 degree. The results showed that with increasing the lip angle from 30 to 45 degree, the maximum depth of scour hole, the lengthwise hole expanse, the height of upstream and downstream berms and the relative surge height, increased in average to 150%, 27%, 110%, 24% and 213% respectively. Based on the results of this study, 30° bucket is an appropriate option to reduce the maximum depth of scour, volume of scouring, height of berms and height of ripples in tailwater to the minimum possible and 40° bucket is also a suitable option to further the beginning and the deepest point of scour hole and the surge peak to the maximum extent possible. Both angles have advantages to reduce bed scour, bucket abrasion (Due to the trapped material in unsymmetrical spillway operation) and negative effects of turbulent rippling tailwater on outlets operation and riverbank.

Abstract Increasing of water scarcity on the one hand and increasing of water contamination, lead us to find a way for removing the heavy metals (HM) from the resources. In this research, Amberlite (IR-120) were used as sorbents of HM. Experiments were done with one diameter of Amberlite. A randomize experimental design was employed with 15 treatments and three replications. The treatment inclouding five different concentrations of NI, Pb and Cd. The concentration for Pd was: 40, 250, 500, 1000 and 1250 mg L^-1 and 4, 6, 15, 20 and 40 mg L^-1 for Ni and Cd. The removing efficiency of the Amberlite was measured for Pb and Cd. The results showed that the effect of concentration was statistically significant for Amberlite. It was also observed that the absorption of HM by Amberlite increases linearly. Maximum Pb, Ni and Cd absorption occurred at 1250, 40 and 40 mg L^-1 with a value of 62.35, 1.98 and 1.99 mg for 1 grams of Amberlite, respectively. The minimum Pb, Ni and Cd absorption occurred at 40, 4 and 4 mg L^-1 with a value of 1.98, 0.19 and 0.19 mg for 1 grams of Amberlite, respectively

Abstract Watershed flood hydrograph derivation is one of the most important hydrologic for hydraulic structures design. One of the most widely used experimental models in this context, is the SCS dimensionless unit hydrograph. Also the Geomorphologic Instantaneous Unit Hydrograph (GIUH) model presented by Rodrigoes-Iturb etal. (1979). Simulates the watershed rainfall runoff process based on quantitive geomorphologic parameters and design rain. In this study the performance of above mention methods wasn investigated over one of the Karoon river sub basin so called Jooneghan basin located in Chaharmahal and Bakhtiari province. Geomorphologic parameters were computed by preparing DEM maps and after simulation, the relative performances of the models were compared. The RME in peak flow calculated by GIUH model, was (11%) while the RME residuat mean squane error in SCS method was (22%). The results also revealed that the GIUH model has performed better than SCS model in estimating flood peakato and time b peak.

Abstract For precipitation regionalization of Kurdistan province and access to a suitable pattern in this context, annual precipitation of 83 stations are collected for a period of 30 years (1979-2008) from Applied Meteorological Research Centre of Kurdistan Province. Using rotated PCA approach by Varimax method showed that approximates 86.75 percent of annual precipitation variations of Kurdistan province can be explained by 7 components. The result of PCA used as an entrance of cluster analysis with Ward’s technique and it was distinguished that Kurdistan province has ? different precipitation regions called west region with high precipitation, central region medium precipitation and east region with low precipitation region. Region East with it,s low precipitation is the biggest precipitation one in the Kurdistan province that Annual mean precipitations is about 368.7 mm. The central region with medium precipitation region is the second large region of precipitation. Annual mean precipitation of this region is about 537.7 mm. Western high precipitation region is the smallest region of precipitation and at the same time it is the wettest region of precipitation in Kurdistan province. The annual mean precipitation of this region is about 706 mm.

Abstract One of the major objective of adsorption studies is the determination of required time for optimal adsorption in the solid-liquid. system In addition to research on the effect of sorbent dose, balance time, the efficiency of adsorption and adsorption kinetics models were evaluated. Fitness of measured data with the predicted value by lagergren and Avrami model showed the model not only gives a good estimation of equilibriuim value of absorption but also describes absorption data well.One of the major objective of adsorption studies is the determination of required time for optimal adsorption in the solid-liquid. system In addition to research on t