Journal of Irrigation and Water Engineering
Year:2019 | Volume:9 | Issue:34 |Papers Count:17

Protecting and preventing pollution of groundwater resources is an essential element. In this research, two methods of DRASTIC and SINTACS were used to identify vulnerable areas of Aleshtar aquifer. In this research, the sensitivity map of the plain was developed for each of these models in a GIS environment. The correlation coefficient was calculated by Pearson method. By comparing this coefficient and the inherent vulnerability index of the above models, the DRASTIC model was chosen due to having a greater correlation coefficient (0. 67) compared to the SINTACS model (0. 50) and modify of the weight of its parameters performed. To ensure the performance of the models, the Pearson method was calculated based on the nitrate layer of the wells and vulnerability maps. Due to the high correlation coefficient between the model of the DRASTIC and nitrate layers and because of the non-matching of the parameters assigned to the parameters in the model with the results of the sensitivity analysis, the AHP ranking method was used. According to the results, the weight of the topographic parameter was 1 to 2 and the unsaturated vadoze zone parameters weight was changed from 5 to 2. 8, and net recharge parameters and soil environment due to negative correlation with the zoning map nitrate were omitted. The modified model (DATIC) categorized the area into three different vulnerability classes, of which 67 percent were negligible, 24 percent were very vulnerable and 9 percent were classified as vulnerable, Based on the results, the Pearson correlation coefficient jumped to 79 percent in the revised version that can be verified by definition Drastic modification is in the Aleshtar Aquifer.

Stilling basin plays an important role in the energy dissipation of hydraulic structures. In this study, five hydraulic jump models that have shown good results in certain laboratory conditions, are compared. 32 tests in Froude numbers ranging from 1. 02-9. 19 with three roughness and three slopes and minimum three discharges are done. Selected beds include a smooth bed, a bed with 1. 6 mm roughness and bed with a roughness of 3. 6 mm. The results showed that reviewed models have errors in hydraulic jump length prediction at different flow regimes. In hydraulically smooth flow, minimum error is 16 percent for the Parsamehr et al model. All models have high error in hydraulically transitional flow but if needed, can be used the model of Mohseni movahhed et al. with an error 53. 7 percent. In hydraulically rough flow rough, none of the models have low error but mohseni movahed model with 57 percent error is more usable.

One of the main goals of diverting water from bend of river is diversion the maximum flow discharge with the minimum rate of sediment to the intake mouth. Therefore, the position and diversion angle of lateral intakes in river bend with sediment control structures, are the major parameters that must be considered. In this study by experimental investigation in a U-shaped channel using compound structures of sill and 10° skimming wall in three diverted flow percentages of 17, 21 and 26, the effect of diversion angle on rate of sediment entering the intake, was investigated. The results showed that with decreasing of the angle of intake, the inflow Froud number decreases. Also with increasing the angle of intake from 45 to 75 degrees, the rate of sediment entry to intake increases, so that by combining of sill and skimming wall 10ᵒ , the sediment transportation into intake mouth decreases more in comparison with basic state. By increasing the angle of flow diversion in all percentages of flow diversion, the width of separation zone at water surface decreases. By investigation of power of secondary flow along the intake mouth it was found that in all experimental states, decreasing the angle of flow diversion from 75 to 45 degrees, causes less decreased power of secondary flow and consequently less sediment entry into the intake mouth.

Water balance analysis is the base of streams management. Because the results like changes in surface water reserve can be used efficiently in decisions and water resources optimum usage. One of the models that is used widely to simulate catchment hydrological ingredients, around the world recently quantitatively and qualitatively, is SWAT hydrological model. This model operates continuously on a daily scale. In this study, surface water balance parameters were evaluated using the SWAT model over the Agh Chai basin. The algorithm SUFI-2 by the SWAT-CUP software package for calibration and validation based on monthly river discharge and uncertainty analysis was used. The results showed that due to the calibration period Nash coefficient is 0. 86 in very good level. The p-factor in the calibration period, equivalent to 17% and the r-factor is equal to 0. 1. These low values, indicating high uncertainty in runoff prediction and good calibration in the basin. The values for validation period are 0. 52, 29% and 0. 14 respectively when considering Nash coefficient was obtained in a satisfactory level. Other values confirm the results obtained in the calibration period also.

Watershed management structures affect the hydrological outflow hydrograph components such as peak discharge, time to peak, base time and runoff volume. The unit hydrograph approach can be used to evaluate the effects of watershed management practices on hydrologic response, through comparison of unit hydrograph derived from recorded observed events before and after the management practices in the watershed. The hydrologic evaluation reports of watershed measures can be helpful in design improvement and implementation of flood control structures. The aim of this study was to evaluate the effect of small detention dams on watershed unit hydrograph response in Jafar-abad watershed (with an area of 10900 ha), Golestan Province. The 43 recorded rainfall-runoff events were analyzed before and after the mechanical measures and the Tc-duration unit hydrograph were derived. In this regard, the D-hr hydrographs were converted to Tc-hr hydrographs using S-curve method. Then the unit hydrograph components were obtained for pre and post construction of structural measures and hydrograph components were analyzed using t-test analysis and Box-and-whisker plots. The results showed an increase in the peak flow and base time of index unit hydrograph and also the time to peak of the unit response decreased due to constructed measures. While, the statistical analysis showed a significant difference (p-value<0. 05) due to the effect of structural measures on unit hydrograph base-time component and increasing it up to 6 hours (on average) in the post construction period. Although the mean value of time to peak has reduced from 15. 9 to 14. 8 hrs, which was not statistically significant. In general, the watershed response and resultant hydrograph component of the watershed are affected due to the implementation and allocation of detention structures in the watershed.

In this study allocation of water resources Choghakhor dam after the operation of the water transfer project Sabzkouh to Choghakhor using system dynamics approach is discussed. For this purpose, the inputs discharg to the reservoir and evaporation rates using SARIMA model to forecast for period 2014-2019 and The best model fitted to the data for input to reservoir and evaporation has been respectively SARIMA (1, 0, 3)(1, 1, 1) and SARIMA (1, 0, 1)(1, 0, 1). In this way all the factors affecting the volume of water in the dam as well as the interaction of supply and demand for drinking water, industry, agriculture and environmental was modeling in programming VENSIM. Then 9 scenarios was defined for the future allocation of water resources. The results showed that the optimal scenario of the dam is able to provide 4, 300 hectares of agricultural land in the state percentage water supply, drinking, industry, agriculture and the environment demands, respectively, 98, 90, 87 and 94. In addition, by changing of the irrigation system from surface irrigation to pressurized system and increasing irrigation efficiency by 30% the cultivated area, can be developed up to 3900 hectares.

The lack of rainfall in arid and semi-arid areas result in the limited availability of surface water resources in these areas, hence water consumption in the agricultural, industrial and drinking industries relies heavily on groundwater. In field surveys, such as sampling from deep wells, determining the critical points for sampling is very important in terms of reducing sample size and saving costs and time. In this paper, the principal component analysis (PCA) and the hierarchical clustering have been used to select the effective wells for measuring the static level of groundwater in the Minab plain in Hormozgan province. For this purpose, 38 piezometric wells were considered and the relative importance of each well was computed using the PCA by allocating the values between 0 and 1. The study showed that by removing the wells with the relative importance less than 0. 7, the coefficient of variation of groundwater doesn’ t increases significantly compared to the case of using all wells. Based hierarchical cluster analysis, the piezometers were divided well into three clusters, which the 3rd cluster with 12 piezometers is the best representative with the lowest error. Finally, the cluster analysis with the lower error compared to the PCA was used as the criterion of conclusion.

Ajabshir plain is one of the most important agricultural areas in East Azarbaijan province, which groundwater resources were applied more than half the water requirement of Agricultural productions in this plain. Continuous utilization of groundwater caused a decline of 5. 5 m from since 1984. Therefore, optimal and sustainable exploitation of groundwater resources in this plain is a management necessity. Consequently, modeling and prediction of the exploitation process could be accomplished by an appropriate technique. This research was conducted with the aim of analyzing the groundwater level variations in Ajabshir plain with time series statistical models due to the ability of time series techniques to model and predict the behavior of temporal variation in water engineering. Also, in this study, the groundwater level decline was modeled for 16 years with 16 models. A Seasonal Autoregressive Integrated Moving Average (SARIMA) was recognized as the most appropriate pattern. Modeling, testing and prediction model was as follows: about 50% of the data for modeling (from 1984 to 2006), 25% for the test (from 2006 to 2017) and 25% (from 2017 to 2028) was used for prediction. Results showed that the average volume of groundwater drop in the 11th year of the forecast (2028) is equal to 26. 5×106 m3 under continued exploitation with the current conditions for agricultural production in the plain. Different saving scenarios, including 0, 10, 15, 20, 25 and 30 percent savings starting from 2018 were considered for optimal management of groundwater application. In the eleventh year, about ×106 m3 of groundwater will be saved with savings of only 10% from 2018.

The climate change and global warming is one of the important environmental humanity issues. For climate change impacts assessment, GCM models are used. In order to use the GCM outputs in the catchment scale, downscaling is required. The SDSM are used to assess the climate change impacts studies extensively, while the scope of SDSM has been evaluatedless. In this research, performance of the SDSM investigated using precipitation, Tmax and Tmin data of Yasouj station, and NCEP large-scale atmospheric variables. Then climate change impats in 2067-93 period was assessed using CGCM3 outputs underA2 scenario. To assess the strengths and weaknesses points of SDSM, precise evaluation was performed at daily, monthly and annual levels. The results showed that the model performance on daily level is good, but not acceptable in annual maximum daily precipitation distributions; on monthly level and reproduction of annual precipitation distributions is acceptable at 90% confidence level; not acceptable on reproduction of annual temperature distributions. In assessing the climate change impacts, it was concluded that monthly mean of Tmax and Tmin in all months will increase relatively the same, the mean precipitation decrease in spring and increase in autumn. It is forecasted that increasing of mean annual precipitation and temperature are 52% and 2. 76 respectively

Rainfall as an input factor for flood modeling and design of hydraulic structures has great importance. Rainfall frequency analysis is a major task for water resources planners and hydrologists. Considering this fact that hydrological phenomena including rainfall are multivariate (intensity-depth-duration) terms, joint modeling of several random variables would be required. Considering the importance of two rainfall characteristics including intensity and depth in flood management and design of hydraulic structures, in this research, copula function was used for the analysis of dependency structure of these two variables. For this purpose, 40 years recorded rainfall data in Minoodasht hydrometry station located on Chehelchay River in Gorganrood watershed was used. In order to determine the allowable risk of structure failure against rainfall, its univariate return period was compared with estimated joint return period through selected copula. In this study, Frank copula led to the best results in bivariate modeling of rainfall intensity and depth, according to goodness of fit tests. Associated return period was estimated by Frank copula to improve allowable structural risk estimation in comparison to univariate return period. For example, an incident with the intensity of rainfall equal to 45. 43 mm/h and its depth of 168. 61 mm for 100 years’ univariate return period is 53 years in "or" case and 954 years in "and" case for bivariate joint return period. Comparison of bivariate analysis with univariate analysis indicates the difference the outcome of these tow methods. As due to the lack of consideration of all effective features in the phenomenon, the univariate analysis of hydrological events would not be a comprehensive analysis, therefore, the multivariate analysis of hydrological events is recommended.

In this research, by presenting a new method using the generalized linear model, the long term effects of climate change on rainfall changes in the Shoor basin under B1, A2 and A1B scenarios were investigated in three periods of 30 years up to 2090 horizons Using the data of daily precipitation and monthly temperature in the base period (1971-2000) in 13 synoptic stations, using generalized linear models, the incident model and the amount of precipitation simulated and used for fine Exponential scale of GCM model data was used. Of the 20 models provided by the CCCSN database, a wide range of climate change changes were introduced. The generalized linear models, by linking the climate and rainfall variables, provide a fine-scale scaling-up of the outputs of the GCM models. The results of the implementation of the generalized linear model show that only two models of INGV-SXG, BCM2. 0 are suitable for producing future scenario scenarios. The results also indicate a decrease in rainfall and a rise in temperature in the coming periods. The highest percentage of monthly rainfall reduction has taken place in the summer season than the base period. Accordingly, the maximum average monthly precipitation during the period 2030-2001, 25. 22%, during the 2031-2060 period, 37. 5% and 2061-2061, between 35. 58% and the base period of the forecast It will be.

Today, due to population growth, supply of drinking water and energy is one of the most important issues in managing water resources. Environmental protection and limitation of fossil resources have caused human attention to be focused on alternative and clean sources, such as hydroelectric power stations are concerned. Therefore, in this study, the evaluation hydro potential of the Sarab Talkh Reservoir Dam in Lorestan province with the aim of supplying part of drinking water and industrial industry in Khorramabad, which is 55 and 5 million cubic meters per year, using the WIP model in a statistical period of 45-Year-old (1965-2010) were investigated. First, Man-Kendall nonparametric test method was used to study the data process. Then, to simulate the hydroelectric potential of the Sarab bakh reservoir, 6 dead level, 6 normal level and 3 different function factors were selected. The results of the trend analysis showed that the discharge rate did not follow a particular trend and was random. Also, the results of Simulation of hydroelectric potential of Sarab balkh dam, with the aim of providing drinking water and industry and economic analysis of operating costs, showed that normal level in comparison with dead level have had a greater impact on energy production and dead level 1424 and normal level 1449 meters of sea level were selected as the optimal number.

In recent years, researchers have considered new methods such as dry drainage, to control the soil water and salinity of the irrigated area of the fields in the arid and semi-arid regions because traditional drainage methods are expensive and need more water. Investigation of water and salts transport in these systems is essential for studying their function. In this study, effect of dry drainage on the soil water content, salinity, nitrate and chloride ion concentrations in a loamy soil was investigated using a physical model under the barley cultivation. Based on the results, dry drainage led to transport a significant part of the salts entering in the irrigated area to the non-irrigated area that accumulated on its soil surface, in addition to controlling soil moisture in the irrigated area. Based on the results, at the end of the experiment, maximum increase of salinity, nitrate and chloride concentrations on the soil surface of the irrigated area were 145, 384 and 135%, respectively, and for the soil surface of the non-irrigated area were 270, 1070 and 160 %, more than of initial values at the start of the experiment. Therefore, dry drainage system was able to control the soil salinity of the irrigated area by transporting the salutes to the non-irrigated area for proper barley growth.

Clogging of emitters is one of the problems of trickle irrigation with saline water. This study was carried out with the purpose of investigating emitters clogging in trickle irrigation using magnetized water under different salinity level. In this study two treatments of magnetized water and non-magnetized water considered were as main factors (variables) and three levels of saline water including waters with saline of 0. 57, 5 and 10 dS/m and three distance including the first of lateral, middle and the end of lateral were as sub-factors. The experiment was laid out with split-split plot in a complete randomized block design with three replications at Babolsar city in 2016. In order to assess the clogging of emitters, the variations of emitter discharges and chemical analysis of water was measured and analyzed. The results showed that the effect of magnetized water on average discharge of emitters and uniformity coefficient was significant (at P≤ 0. 05). At the end of the irrigation season, the average discharge of emitters used for the magnetized water was 7. 3% higher than the non-magnetized water. Also, the uniformity coefficient of emitters used for magnetized water was 7. 9% higher than non-magnetized water. For saline water of 10 dS/m, the average discharge of emitters was 4. 02 L/hr at the first irrigation period and reached 3. 69 L/hr at the final irrigation period, while for magnetized water, it was 4. 05 L/hr at the first irrigation period and reached 3. 85 L/hr at the final irrigation period. According to this research, the using magnetized water is recommended in order to decrease the emitter clogging and increase the water uniformity in the field.

According to decline in water resources availability and quality and also increases population growth, one of the most important strategic policies for food security is agricultural vertical development which can be achieved by improvement of water productivity. Deficit irrigation by employing alternate furrow irrigation is one of the methods of water management in the field that its application increases water productivity and yield per each irrigation water unit. This study was conducted to evaluate and simulate the alternate furrow irrigation for wheat using SIRMOD model. To reach these aim, some experimental data for Kerman Zenderooh agricultural and environmental research center during 2005-2007 were used. This research was based on randomized complete block statistical design with four treatments normal and alternate furrow irrigation method with two planting distances 50 and 60 cm (T50, T100, T60 and T120) in three replications. Evaluation results by model showed that efficiency of application, irrigation and distribution of water can be improved 2 times in alternate furrow method as compared to normal method. There were 4, 10, 27, 43 minutes difference between observed and computed data of water time advances in treatments T60, T120, T100 and T50, respectively. In total, observations showed that alternate furrow irrigation with a spacing of 60 cm (T120) is suitable for wheat, even in sandy loam soils. This increases the efficiency of application, irrigation and distribution.

Present research has been executed in Kerman Province during 5 years in order to hillside orchards development by using rainwater harvesting catchments. Towards this attempt, in a rangeland of 5 percent slope, microcatchments were made with 5 different treatments including removed surface with gravelly filter, removed surface without gravelly filter, isolated surface with gravelly filter, isolated surface without gravelly filter and natural surface, with 5 replicates and 3 cultivars of almond (Botter Almond, Sweet Almond and Hamedani). Vegetation parameters (diameter, height, covering crown, existing and crop yield) were measured After cultivation of twigs in down part of microcatchments. The results showed that the means of variables are the lowest value in natural surface treatment and be increased in removed surface without gravelly filter, removed surface with gravelly filter, isolated surface without gravelly filter and isolated surface with gravelly filter respectively. So that in fifth year, mean values of diameter, height, covering crown, existing and crop yield in isolated surface with gravelly filter are 58. 5 mm, 258 cm, 2. 5 square meters, 1. 2 kg for each tree and 100 pecent. Also between 75 almond trees with 3 cultivars, Shahrood 21 had better growth than others. So utilization of isolated surfaces with gravelly filter can be recommended in supplying water for hillside orchards in watersheds using rainwater harvesting systems.