مجله مدیریت آب و آبیاری
سال دهم شماره 2 (پاییز 1399)

The study was conducted at the experimental farm of college of Aburayhan of University of Tehran located in Karaj. The aim of this study was to investigate the effect of using superabsorbent polymer on flow hydraulic parameters of the flow and water infiltration in furrow irrigation. For this purpose, two types of superabsorbent A200 and Stockosorb with two values of 16 and 30 g/m2 of soil under two different flow rates (0.3 and 0.6 L/s) were used. The experiment was carried out in five irrigation regimes and in non-cultivated conditions in the summer of 2018. The results showed that both superabsorbents increased the time of the advance and recession and increased their amount by increasing the amount of superabsorbent. Also, the results showed that the addition of super adsorbent to soil decreased the runoff and increased the amount of infiltration, and with the increase of the flow rate to the furrows, the effect of superabsorbent was reduced. Stockosorb superabsorbent had a greater effect on the increase in advance and Recession times and enhance of water penetration in the soil.

Water restriction is one of the main inhibitors of crop production. Therefore, choosing a superior and superior strategy is essential for making water in its design. For this purpose, an experiment was conducted in a split plot in a randomized complete block design with three replications at the Semi-drainage Research Farm on roselle. Treatments included four levels of irrigation water (120, 100, 75 and 50% of plant water requirement) and three levels of potassium fertilizer (100, 75, 50 and 25% potassium). The purpose of this research is to estimate the production capacity, index calculations, and water intake. The best sour tea production function was selected from four production functions (linear, logarithmic, quadratic, and transcendental) based on the lowest error statistics. In order to investigate the separate and combined effects of potassium fertilizer and irrigation water depth from end production to depth of irrigation water (MPI), end production to potassium fertilizer (MPk), final ratio of technical alternative rate to potassium fertilizer and irrigation depth (MRTSI, k), final production value for irrigation water depth (VMPI) and final production value for potassium fertilizer (VMPk) were used. Final production index was 1.4 for water depth at minimum depth of irrigation water (MPI) and its value for maximum irrigation depth was -0.86 kg/cm depth. It was water. The final production index for minimum and maximum potassium fertilizer consumption was 3.92 kg and 3.77 kg, respectively. The results also showed that by applying irrigation under water limitation conditions, the optimum depth of water consumption compared to the maximum depth of water use at levels of 75, 121.5 and 150 kg potassium fertilizer were 13.29, 14.34 and 1.1, respectively. It has reduced water consumption by 13 cm. As can be seen, increasing the potassium fertilizer up to 75% resulted in more water savings. The use of potassium fertilizer can reduce the damage caused by drought stress in roselle.

One way to balance the environment is to study and manage aquifer vulnerabilities. In order to decide and manage the aquifer, the need for planning to identify vulnerable areas is very important. Several methods and indicators to assess the vulnerability of the aquifer are presented in each of these indicators is based on a set of factors used. In this study, 5 vulnerability indicators have been used in the coastal region to investigate and compare these methods. The characteristics of DRASTIC, SINTACS, SI, GALDIT and GODS were investigated to assess the sensitivity of the aquifer inherently. The results of these 5 indicators were different according to the nature of each of them and in order to increase the accuracy of the results and practical use of these results in coastal areas, weight and rankings were performed using hierarchical and entropy analysis method. For this purpose, the correlation between the vulnerability index concentrations of TDS, nitrate and chloride and weights of each indicator was calibrated. Sensitivity analysis of various parameters in vulnerability indicators showed that GALDIT index reflects this sensitivity in the results, considering the effect of sea salt water progress. Depth parameter to static level in other indicators and distance parameter from the sea is a sensitive and important criterion in GALDIT index and after model calibration, it was found that 30% of aquifers are exposed to the saline fronts of sea water infiltration.

About 90 percent of the water used in greenhouses is allocated to the two processes of evapotranspiration and cooling of the environment. A large amount of water used in greenhouses is driven out useless in the form of humid air by the fan, which is recyclable and can be reused in the greenhouse water inlet cycle by condensation. Therefore, the purpose of this study is to investigate the possibility of water production from humid air exiting the greenhouse. In the next step, the effects of heat exchanger length and inlet air velocity were investigated on the amount of recycled water. This study was conducted in 9 experimental treatments with three lengths (0.5, 1 and 1.5 m) and three inlet air velocities (0.5, 0.8 and 1.2 m/s) inside a greenhouse model with dimensions of 2x1.5 x 2 m3. The measurements were done with dimensions of 1.5 × 1 × 2 m3. The results showed that increasing the heat exchanger length and inlet air velocity increase the water production and the highest condensed water achieved at heat exchanger length of 1.5 m and an air velocity of 1.2 m/s. Also, the amount of water produced was about three times higher than normal condition without condensation, up to a maximum of 60 liters at a length of 1.5 m and velocity of 1.2 m/s. The results showed that about 10 to 30 percent of the water used for irrigation and cooling (fan and pad) the greenhouse can be recovered by using a heat exchanger.

One of the most important issues in water resources management is the preparation and development of appropriate models in order to predict the streamflow more accurately. For this purpose, in the present study, linear time series models (ARMA), intelligent Bayesian network (BN) and BN-ARMA hybrid model have been developed for forecasting the monthly river flow of Bakhtiari River in 1955-2016. The performance of the developed models was evaluated based on statistical indices such as root mean square error (RMSE), correlation coefficient (CC) and Kling-Gupta index (KGE). Among the time series models fitted to the data, the AR (3) model was selected as the appropriate model for monthly stream flow series, with the lowest value of the modified Akaike information criterion equal to 1089.3. The results showed that the AR (3) model with an error of 47.786 (m3/s) has acceptable performance. The monthly river flow from the previous month, two months and five months ago was used to model the monthly river flow using the BN model. The results indicated that with three months intervals, the model performance is optimized and its performance is weakened by increasing the number of inputs. The correlation coefficient, root mean square error and KGE in the best case of BN model in the test stage are 0.826, 45.303 and 0.789 (m3/s), respectively. Next, the combination of BN and ARMA(3.0) models was performed. The results showed that the BN-ARMA hybrid model significantly increases the accuracy of the modeling and reduces the prediction error from 45.303 (m3/s) to 15.021 (m3/s).

Modern irrigation systems are one of the most important factors affecting crop production, water consumption and productivity, but the performance of these systems requires careful consideration. For this purpose, a study on the effect of surface and subsurface drip irrigation systems with different levels of deficit irrigation on yield, yield components, and water productivity in SC 704 maize, a factorial split design based on randomized complete block design was conducted in the field of Deputy of Soil and Water, Ministry of Agriculture (Karaj) in summer of 2018. The treatments were included %100, %75 and %50 of water requirement in each type of surface and subsurface drip irrigation. A total of 54 irrigation drips were tested. Based on the results, the interaction of stress and irrigation method for plant length was non-significant, and dry plant weight and harvest index were significant at 1% probability level and other traits at 5% probability level. The results also showed that the highest grain yield 22.33 ton/ha and 22.31 ton/ha, were obtained from DI=%100 IR and SDI=%100 IR treatments, respectively, which were not significantly different between these treatments. The lowest grain yield was obtained from DI=%50 IR treatment which had a 33% decrease in yield compared to non-stress treatment in surface drip irrigation. The SDI=%50 IR treatment had the highest irrigation water productivity (2.75 kg/m3) among the other treatments. The water productivity of this treatment increased by %53.6 compared to the non-stress treatment in subsurface irrigation.

Forecasting stream flow is very important for planning and managing water resources systems and its precision has a significant role in accurately implementing the planned objectives. Besides, soft computing has a significant ability in modelling hydrologic processes. Therefore, in the present study, the Hybrid Wavelet-Gene Expression Programming model has been developed in comparison with its singular approach so that it forecasts the daily streamflow of Khoshkroud river located in Guilan province. For this purpose, in addition to the process of pre-processing hydrometric data, the effect of meteorological parameters on the model’s performance and efficiency has been studied. Also, pre-processing was performed with different properties and for four durations of one, two, three and six days. Correlation coefficient (R), index of agreement (Ig), Nash-Sutcliffe coefficient (NSE), mean absolute error (MAE), root-mean-square error (RMSE) and peak flow criteria(PFC) statistical indices were used to assess the models’ performances. The results show that using wavelet transform to pre-process hydrometric data will significantly improve the efficiency of the hybrid model in comparison with the singular model, such that the correlation coefficient of the validation data for three days has increased from 0.27 to 0.80 and similarly, the mean absolute error has decreased from 1.4 to 0.80 m3/Sec. On the other hand, meteorological parameters have caused the extreme values in the river’s flow rate time series to be well modelled and their efficiency in the extreme values to be significantly increased. The results obtained from this research express that the hybrid model alongside the meteorological parameters can be successfully and efficiently used in flow forecasting.

The quantitative and qualitative degradation of groundwater resources has become a serious crisis due to high consumption in agriculture, population growth and urbanization, and the industrialization of communities. Rehabilitating groundwater aquifers is one of the main requirements in aquifer management. In this study, the effect of improving the performance of irrigation district and, of course, reducing waste in the process of transfer, distribution and delivery of agricultural water, balancing and rehabilitating aquifers were examined. For this purpose, in the first step, the numerical model of Qazvin aquifer, with the code MODFLOW, was developed for spatial equilibrium analysis of aquifer. Then, the hydraulic simulator model of agricultural water distribution system flow in MATLAB software was developed, calibrated and verified and the automatic control system of the distribution system was linked with the automatic control model. Finally, by linking the developed models, the effect of using the method of improving the operation of the irrigation district, in the form of a scenario for balancing the aquifer, was examined. The results showed that with the improvement of the performance of the agricultural water distribution system, even in low water conditions, the average efficiency index of agricultural water distribution in agricultural areas in the decentralized automatic control system has been about 32.7%. Accordingly, the rate of decline in aquifer harvest was 45.3% in the decentralized automatic operation method. The results of numerical modeling of aquifer for spatial analysis of aquifer balancing showed that in the usual method of groundwater level operation, the increasing trend continues to decrease. The results show an annual drop of about 150 cm under the usual method of operation. By using a decentralized automatic control system and increasing the adequacy of water delivery in this method, this increased the level in the observation wells located in the irrigation district. The equilibrium solution for aquifers presented in this study can be developed for all agricultural areas (irrigation district) whose water supply sources are a combination of surface and groundwater resources.

Water insecurity is a growing concern worldwide, especially for developing countries, where a wide range of activities, including agriculture, depend on water supply systems. Iran is no exception. For example, the increasing use of surface and groundwater resources in the Mashhad plain as a result of the development of agriculture and related industries in this plain has led to an intensification of the declining trend of its aquifer level. Therefore, the resilience of Mashhad plain is very important in reducing groundwater resources. In this research, it has been tried to analyze the priority of these variables after determining the basic variables affecting the model, according to the opinion of experts and using the two best-worst business methods and the process of hierarchical analysis. In the future, knowledge will define the basic strategies for increasing the resilience of these resources in this plain. According to the literature review, this research is the first attempt to apply the best-worst business method in this field of research. The results of this study showed that the discharge rate of groundwater in agriculture with a final weight of 0.18103 in the BWM section and 0.21216 in the AHP section, respectively, the existing agricultural groundwater resources with a final weight of 0.0444 in the BWM section and 0.174165 in the AHP section, the amount of surface and groundwater losses in the agricultural sector with a final weight of 0.10248 in the BWM section and 0.884 in the AHP section, with different order in the two methods, are of the highest importance.

Construction of weirs in river bends results in the non-uniformity of water flow across the channel bend and the poor performance of intake structures on both sides of the river. The main hypothesis for enhancing the uniformity is the change of the weir-crest profile from horizontal to sloping crest. The aim of the present study was to test the performance of horizontal and sloping broad-crested weirs in a channel bend under clear flow conditions, using both experimental and numerical models. The FLOW-3D model was calibrated and verified with the use of the experimental data. The numerical model was then applied for the simulation of different scenarios to test the effects of such parameters as the location of the weir at the bend; slope of the weir’s crest; geometries of bilateral intakes including alignment, width and sills; and upstream flow conditions. The results indicate that the sloping crest weir provides an enhance performance by reducing transverse gradients of water surface at upstream control section, and thereby increasing the flow rates towards the two bilateral intakes. It is concluded that a weir with sloping crest (in the range of 2º to 5º toward the outer bank of the bend), at the position of 30 to 60 degrees along the bend, with the intake angle in the range of zero and 60 degrees (respect to the main channel flow), the ratio of intake to main channel width of (1:10), and with the use of entrance sill satisfies the requirements for a better performance. The intake angle of zero is the best choice. In the case of normal intakes, the weir is recommended to be placed at 30 degrees downstream of the bend entrance.

Irregular withdrawals from water resources followed by the increase of the area of under cultivation lands and the construction of Marun and Jarahi Dams on upstream rivers of the Shadegan Wetland have led to severe hydrological changes as well as increased salinity of the wetland inflow in some periods. The aim of this study is to develop a simulator-optimizer coupling model for proper planning and management of resource allocation to the upstream of Shadegan Wetland. In addition to maximizing the supply of basin demands during the operation period, this model tries to decrease the salinity of inflow to Shadegan Wetland. Due to the importance of the wetland as a seasonal habitat for birds and also one of the important tourist attractions and Importance of Protecting the Ecosystem, the development of a quantitative-qualitative optimization model for optimal use of available water resources is the aim of this study. First, based on current conditions, the prepared model is developed as a reference scenario for a future 30-year period (2021 to 2050). To achieve the best system efficiency in terms of quality and quantity, the optimization is performed by means of the NSGA-II algorithm. The results indicate that the optimizer model performs appropriately in supplying various demands and also decreasing the salinity of the inflow to Shadegan Wetland compared to the reference scenario so that in addition to supplying the demands with more than 92% reliability in the whole system, it is expected that the salinity of the river at the entrance to Shadegan Wetland to be reduced by about 50%., especially in low water months. The coupling model proposed in this research is applicable for other study areas with quantitative-qualitative exploitation approach and is able to detect critical points of rivers in terms of quantity and quality. This model has also the capability of providing optimal solutions for improving river conditions as well as downstream ecosystems.

Lack of water resources is one of the most important challenges in water management in the country, which is becoming more important due to increasing demand due to population growth and agricultural development. Considering water as a valuable and real-price commodity can provide a good way of consumption and incentives to store and protect it. The purpose of this article is to investigate the role of the market in the optimal allocation of water in the Shazand plain. Changes in the area under cultivation of irrigated crops, yield in two cases (existence of water market and absence of water market) in the crop year 2018-2019 were calculated and compared using Gamz software and positive mathematical programming method. Requirements have been prepared as a library from the Regional Water Organization, Agricultural Jihad and the Management and Planning Organization of Markazi Province. The results show that the establishment of a water market will have a positive effect of 4.33% on the gross profit of farmers in the region. Also, growing crops such as wheat, barley, pinto beans, chickpeas, white beans and lentils are more profitable and can take up more cultivation area. Based on the results, it is suggested that in order to optimally manage water demand in Shazand lands, the necessary basis should be provided for the formation of water market and farmers in the region should export and trade products such as pinto beans, white beans, chickpeas and lentils, etc. To replace more profitable products with high water consumption and low profit.