Journal of Irrigation and Water Engineering
Year:2015 | Volume:6 | Issue:21|Papers Count:13

Morphology of rivers constantly changes due to their dynamic features, and these changes can negatively affect the structures in riversides, agricultural lands, etc. Meanders are considered as important indicators of environmental change. This study examines the changes of the sealing degree and meander shapes of the Kashafroud river using 1966 aerial photography, 1987 Landsat TM sensing images, and 2013 Google Earth images. In this study, morphological parameters of 16 meanders in a range of 11 kilometers along the Kashafroud river was determined for each period. The results of the paired t mean comparison showed that changes in the sealing degree ranging from 1966 to 2013 have a significant difference at level of one percent. To determine the effects of changes in some meanders parameters on sealing degree, multivariate linear regression model was used. The results showed that in case of change in the sealing degree, meanders reduce along the river. In addition, Spearman correlation analysis showed that changes in the parameters of sealing level and meander shape are strongly interdependent, so that there is a significant correlation between changes in sealing degree and meander shape at level of one percent. With increasing degree of sealing, meander shapes convert into U and  W shapes, and meanders tend to close. In meanders with reduced sealing degree, such as meanders number 2, 3, 11, and 12, the path will mainly change into a strait one, and a part of the river will be separated as bovine horn ponds.

The accuracy of the classical methods to calculate evapotranspiration of plants for use in large areas may not be sufficient and therefore less useful. Thus, the choice of high-precision approaches, despite of restrictions ahead seems necessary. The purpose of this study is calculation of sugarcane evapotranspiration in Ahvaz, Khuzestan province using two methods. In method one, soil evaporation and crop transpiration were separately calculated using NDVI index extracted from MODIS images in. In the second approach, evapotranspiration was estimated using single crop coefficient approach known as FAO 56 method using available coefficients. Besides, crop coefficient values were calculated using SimDualKc software during entire growing season and FAO Penman-Monteith equation was worked out accordingly. The results were also compared to a lysimetric dataset. Correlation coefficient of ET estimations using single and dual crop coefficient approaches with lysimetric measurements were 0.954 and 0.885, respectively. A. On the other hand, the standard error for single coefficient approach was 67.29 and 29.34 dual approach. The results showed that the remote sensing-based dual coefficient approach provides acceptable estimations of sugar cane in the region. More studies are recommended for further scrutiny.

Currently, agriculture is a crucial support for the national food security as well as economic sustainability. Among all factors, water is the most important and limited production factor. The simulation models of yield response to the water and irrigation water salinity are expected to play an increasingly important role in the optimization of water productivity (WP) in agriculture. AquaCrop model is a powerful and valuable tool for improvement of water management in the field and calculating water productivity. In this study, canopy cover, yield, biomass and evapotranspiration of cotton were simulated by using AquaCrop model under different levels of water salinity and deficit irrigation condition. The treatments included three levels of irrigation water salinity and three levels of irrigation depth. The experiment design was laid out with split-split plot in a factorial design with three replications. Results showed that the model can simulate different parameters with high accuracy (d>0.95). By reducing the amount of irrigation water and increasing of irrigation water salinity, simulation error was increased, but simulation results were in the acceptable range. For low levels of water and salinity stress, there was no very difference in the simulation results. AquaCrop model can be valuable tool in water and salinity management.

Employment of hydroelectric power plants is considered as one of the strategies to overcome the water shortages in the world. On the other hand, increasing the generated electricity by using of water energy is of importance. Regarding to the high cost of construction of dam and supplying the required hydraulic head of hydro power stations, the optimum design of these stations has been considered. Penstock, among the components of these stations, has a special place. The importance of penstock is due to its high manufacturing, installation and maintenance costs which assign nearly thirty percent of theplant’s expenditures to itself. Therefore, optimal design of this hydraulic structure will play a significant role in lowering the construction costs of hydro power stations. The use of meta-heuristic optimization algorithms for optimization of different structures has been one of the most important issues in designing of these structures. Among the meta-heuristic algorithms Particle Swarm Optimization has been considered as a powerful method in many fields. The purpose of this research is to present an optima sketch to maximize the power of jet streams reaching the turbines and also reduction the pressure losses through penstocks for controlling the transient flows. The results show that the energy losses have totally been decreased from 29.11 meters to 11.92 meters. This reduction lead to increasing the efficiency and performance of high pressure pipes. The pressure losses due to sudden changes in flow condition (before optimization) are 315.9kpa which by optimization of the penstocks decreased to 116.7kpa. This reveals that by reduction in pressure losses, the damages caused by transient flows are greatly decreased. Also, the power of flow increased from 25MW to 28MW, which equals 11%.

As a crucial issue in aqua sciences, optimizing dam reservoirs exploitation has been studied with a variety of optimization techniques. One of these methods is using Meta-Heuristic algorithms such as Firefly and Ants Algorithms. Using the firefly algorithm, this study studies the exploitation optimization of Doroudzan reservoir in a 99-month period. The most sensitive parameter in sensitivity analysis of Firefly Algorithm, α, is known as the mutation rate. Selecting its appropriate value by Firefly worms leads to an appropriate solution and increases the efficiency of the Firefly Algorithm dramatically. To determine the efficiency of this algorithm in optimizing the utilization of the dam reservoir, the obtained results were compared with the results of Continuous Ant System and Ranking Ant System. The findings indicated that FACC algorithm with objective function rate of 4.196 had a satisfactory performance. ACOrCC and ACOrankCC algorithms with the values of 17.004 and 26.156 followed it respectively. In addition, FACC algorithm with a value of 0.959 had the highest reliability coefficient. The results indicated that regarding Chain constraints, all program performances led to feasible solutions; however, ignoring chain constraints, the Continuous Ant System algorithm was unable to find a feasible solution. Hence, applying these constraints in the main structure of this algorithm would enhance its efficiency significantly.

From ancient times, flood and its mitigation methods have been important to human in order to reduce damages threatening people and nature. Detention rockfill dams which are from the structural methods can control the flood risks in downstream by decreasing the maximum discharge of the flood and increasing the total time of its hydrograph. In order to have an efficient design of these dams, the important conditions of sediment transportation through dam body and also the optimum thickness of the dam should be known. The optimum thickness of detention rockfill dam leads into the maximum reduction in flood peak discharge and also causes the increment of flood duration to get minimized. To find this optimum thickness, some experiments were done on a simulated porous media in a lab. Then, the experimental results were utilized in Monte Carlo probabilistic method in order to find the percentage of sediment transportation probability. Results depict that by using mixed sediment with non-cohesive mean diameter of 0.6 mm within the water flow, optimum thickness would be 7 to 8 times greater than the rockfills with mean diameter of 2 cm in the dam body; while using non-cohesive sediment with mean diameter of 0.2 mm in the flow causes the optimum thickness of the detention rockfill dam to be 7 times greater than body rockfills with diameter of 5 cm.

In recent decades, Evolutionary algorithms have been applied successfully in various water resource engineering and management issue especially in optimal operation of reservoirs. In this research, a metaheuristic algorithm called Wolf Search Algorithm (WSA), has been developed in MATLAB software, with the purpose of optimal allocation strategies of a Multi-reservoirs system (Golestan and Voshmgir dams) located at Gorganrood Basin (North of Iran), for a five year period (from 2007-2008 to 2011-2012). At first, the performance of the developed model was investigated through several standard test functions. Next, the developed model is applied for monthly allocation of Golestan and Voshmgir reservoirs system. The results of the developed model were compared with Genetic Algorithm (GA). The objective function was defined as the “minimization of the total deficit for the study period”. In order to performance evaluation of the investigated Algorithms, two criteria of reliability (temporal and volume) and vulnerability have been used. The WSA and GA were capable to supply 95.37 and 87.07 percent of Golestan dam water demand, respectively. For the Voshmgir dam, the mentioned models could supply 93.8 and 87.59 percent of water demand, in same order. The temporal reliability (a=0.9) for WSA and GA models, was obtained 81.67 and 26.67 percent for Golestan dam and 83.33 and 38.33 percent for Voshmgir dam, respectively, revealed that the WSA was superior in optimal allocation of Multi-reservoirs system.

In order to evaluate the effect of organic fertilizers and irrigation thyme and experimental performance during 90-1388Dr Agriculture and Natural Resources Research and Education Center in Kerman province was conducted. The experiment was a split plot in a randomized complete block design with three replications. Major irrigation treatments on two levels five and 10 days of treatment and use of green manure green manures five sub-levels of control, clover, vetch, alfalfa and manure 30 tons per hectare. Studied the characteristics of fresh and dry weight, dry weight, dry weight of leaves and plant height. The results of the experiment years were tested using the combined analysis. The mean characteristics were compared using Duncan's multiple range test. The results showed the effects of the all studied traits in the plant age and were a significant percentage of the dry weight per unit area was added. The dry weight of the third year and respectively 48 and 101 grams per square meter by Md. tymar irrigation had significant effect on all traits. By reducing irrigation in dry weight was added. The fresh and dry weight, respectively 316 and 90 grams per square meter of irrigation was 5 days. The effect of green manure compared to the control group were statistically significant on all traits. The maximum weight of 30 tons of manure treatment plants, respectively hectares (424 square Rmtr g), clover (291 g square Rmtr), alfalfa (267 sq meter heated), vetch (245 g square Rmtr), control (no use of animal Kv.d) (225 g square Rmtr) is obtained. The results showed the highest fresh thyme daenensis of the third year and the 5-day irrigation and using 30 tons of manure per hectare, equivalent to 581 grams per square meter, respectively. However, the maximum weight of 30 tons per hectare of manure treatment, but the use of green fertilizers were compared to control fresh weight.

Groundwater drought occurs when groundwater as a source of water supply, are affected by prolonged Meteorological drought. In groundwater drought process, at first groundwater recharge, later groundwater levels and finally groundwater discharge are decreased by other Droughts effects. In this Condition, An integrated water resource management based on awareness of spatial and temporal distribution of this type of drought will be essential. in this research, standardized water level index (SWI) and Groundwater Resource Index (GRI) have been used to assess detail of spatial and temporal of groundwater drought occurrence in Marvdasht Kharameh study areas aquifer. Thus, Groundwater level data of 67 Piezometric wells has been used for 2001 to 2011. Drought Index maps generated in Geographic Information Systems (GIS) environment with Inverse Distance Weight (IDW) method. Analysis and interpretation maps and result of calculations of two indexes reveal that the Groundwater Drought began from 2007. And three characteristics of drought include: Duration, Severity and Frerequency are increasing with increasing time scales. The spatial coverage of this type of drought gradually shifts from northern of case study to middle and finally shifts to southern part during the time study.

Because the lack of precipitation in arid and semi-arid regions and therefore limitation of surface water resources in theirs, water usage in agriculture, industry and drinking heavily dependent on groundwater. For this reason, the study and evaluation of the quality of these resources is more important. The present study was done in order to classify groundwater quality of Ghir plain using statistical techniques, including factor analysis (FA) and Hierarchical clustering techniques (HCA) (Based on K-means/K-medians cluster analysis (KCA) method), on qualitative data (14 parameters) in a 10-years period (1391-1381) and SYSTAT13, SPSS 18 and PcOrd softwares. Factor analysis results showed that the variables of SAR, Cl, Na, PH, SO4 and HCO3 with the highest factor loading respectively are the most important parameters to performing clustering analysis. In order to determine the optimum number of clusters used from Davis- Boldin index and according to this index, five clusters were determined for classification of wells. The Results revealed that the KCA and HCA methods have jointed 100% in order to classification. According to the classification results, amount of the parameters of groundwater samples increasing from first to fifth groups. However the wells are placed in Group 1, have the best water quality.