مجله آبیاری و زهکشی ایران
سال هفدهم شماره 2 (خرداد و تیر 1402)

In this research, considering the issue of rethinking the design of different parts of the open overflow system based on the multi-level risk method in the implementation of the Qezal Dash overflow project, the statistical community of the research, in addition to the opinions of all managers and stakeholders of the Qezal Dash dam, including the opinions of experts He has also been an expert in the subject of research.In this section, expert opinions regarding the issue of multi-level risk method of each of the processes and executive departments in the field of support and elimination of safety risks of Qezal Dash Dam have been investigated. Examining the opinions of experts has shown that reducing the safety risks and risks of Qezal Dash dam in terms of time and money in the implementation stages in the field of support and elimination of safety risks of Qezal Dash Dam can greatly reduce both the time of doing the work and the risks. to reduce the safety and anticipated risks of Qezel Dash Dam.The investigation showed that the risk of errors in the control structure has the highest risk (47.167 times) and rethinking in this part has the highest degree of importance. The investigation has shown that the risk of cavitation phenomenon (37.668 times) has the highest risk after the risk of defects in the control structure, and rethinking in this section has the highest degree of importance. The investigation showed that the risk of imbalance in the discharge channel (30.666 times) compared to the existing capacity after the risk of defects in the control structure and the risk of cavitation phenomenon has the highest risk and rethinking in this part has the highest degree of importance.

The most important method for monitoring hydrological drought is the use of drought indices based on river flow. These indices are generally based on the assumption that the river flow volume data series follows the gamma distribution and the principle of equal probability transfer. Therefore, in this research, the aim is to investigate the suitable distribution of monthly flow data and its effect on the characteristics and classes of drought using the standardized runoff index (SRI) in different climates of the country. For this purpose, monthly data of precipitation, temperature, evaporation and transpiration and runoff were collected from 40 synoptic stations across the country during the period of 1979-2020. Then, from the reanalyzed ERA5 model of the ECMWF datasets with a spatial resolution of 0.5 x 0.5, the mentioned data and runoff during the selected period have been extracted. Statistics such as correlation coefficient (R), standardized mean square error (NRMSE) and mean skew error (MBE) are used to compare model data with observational data. In the following, the SRI index was calculated for two time scales of 3 and 12 months based on the fitted Gamma distribution and the best distribution, and drought characteristics including intensity, duration and frequency were calculated for them. The results of ERA5 model data evaluation indicate more accuracy of temperature variables, evapotranspiration potential and precipitation with average NRMSE equal to 0.09, 0.62 and 1.02 respectively. Considering the change of drought classes by changing the distribution used in the index, the results of this research show the necessity of fitting and choosing the best distribution in the calculation of hydrological drought indices.

Today, the role of mathematical models in investigating the state of water resources is more prominent than other methods. Therefore, building a mathematical model of the groundwater table and applying management scenarios to it can provide a better view of the future conditions of that aquifer for better management. This research was conducted with the aim of building a conceptual model of the Babol-Amol plain aquifer and investigating the water balance, over-harvesting, the amount of water entering and leaving the study area, and management measures for the sustainability of the current and future situation based on the data of 1985-2021. The results of the water balance investigations of the Babol-Amol alluvial aquifer show that the recharge volume of this aquifer is equal to 312.01 and its discharge volume is 313.41 million cubic meters, which represents the deficit of the volume of the aquifer by 1.4 million cubic meters. It can be seen that the balance of the groundwater table of the Babol-Amol aquifer and accordingly its groundwater level is in relative harmony, but in recent years, on the one hand, due to the increase in the area under rice cultivation in two cropping seasons in the summer, the water level of the aquifer has decreased, and on the other hand, the use of fertilizers and poisons for rice fields has increased significantly. Fertilizers are also drained from the rice fields and seep into the lower layers, and in the rainy season, the rise of the aquifer water level causes the pollution of the groundwater. To prevent these problems from becoming critical, this aquifer needs strategic management in order to maintain the balance of the aquifer and not be polluted in terms of quality, so well drainage in rice fields is one of the solutions recommended for further investigation.

In order to investigate the effect of different water managements on yield and yield components of Quinoa (c.v. Titicaca), a factorial experiment based on a complete randomized block design was conducted with three replications at Neyshabur city in 2018. Five irrigation water management (furrow irrigation (SI), low-pressure drip irrigation by Tape in the middle of furrow ridge (TI), low-pressure drip irrigation by Tape on both sides of the furrow ridge in alternate every other furrow (ATI), low-pressure drip irrigation by Tape at 75% full irrigation on both sides of the furrow ridge in alternate every other furrow (0.75 ATI), low-pressure drip irrigation by Tape in the middle of furrow ridge at 75% full irrigation (0.75 TI) were employed. The results of comparing the averages showed that the highest amounts of Quinoa grain yield and 1000 kernel weights were 1805 Kg ha-1 and 2.35 gr, respectively, for SI while the lowest ones were 1352.7 Kg ha-1 and 1.69 gr, respectively, for 0.75 TI. The TI, ATI, 0.75 ATI, and 0.75 TI treatments lead to a decrease in the Quinoa grain yield of 12.4, 11.6, 18.7, and 25.1%, respectively, as compared to the SI treatment. The best production function of yield-irrigation water was a linear function (Y=1014 +0.13 I).

Rapeseed (Brassica napus L.) containes 40 – 46 percent oil and rich in unsaturated fatty acids such as oleic and linoleic and has a high nutritional value. The abiotic stresses such as drought stress causes to decline the quantitative and qualitative yield of many field crops in developing countries. In order to evaluate the foliar application effects of Zn and Fe micronutrients on growth and yiels of rapeseed under deficite irrigation condition, this experiment was carried out as factorial based on complete block design with three replications in two regions of Qazvin and Karaj, Iran 2019 cropping season. Three levels of irrigation regims including whole irrigation, cutoff irrigation from flowering stage and cutoff irrigation from silique stage and four levels of micronutrients including zero (as check), foliar application of Zn, Fe and Zn + Fe as 3×4 factorial as main plot and two varieties of rapeseed as sub plot comprised experimental treatments. Results showed that seed yield, relative water content and some fatty acids such as linoleic, palmitic and stearic deccreased in response to drought stress caused by cutoff irrigation from flowering stage and micronutrients deficiency and foliar spraying of Zn + Fe enhanced them equal 136.13, 8.20, 7.72, 12.87 and 22.55 percent, respectively. Some evaluated traits such as stomatal resistance, prolin, soluble carbohydrates and oleic, linolenic and erucic fatty acids increased under cutoff irrigation condition from flowerin stage compared to whole irrigation. Result showed that integrated application of Zn and Fe as foliar spraying through increasing of stomatal resistance and increasing of stomatal conductivity and relative water content caused to enhance seed yield of rapeseed under drought stress condition.

Evaluating the relationship between drought events and greenhouse gas emissions from agricultural activities is of particular importance due to their wide-ranging effects on the environment and economy. The purpose of this study is to investigate the relationship between the emission of GHGs resulting from the production of 18 main crops in the form of five dominant categories including; cereals (wheat, barley, rice and maize), legumes (alfalfa, bean, pea and lentil), oil seeds (soybean, sunflower, canola, safflower, castor, sesame and peanut), tubers (potato and sugar beet) and fiber (cotton) with drought indices including; Standard Precipitation Index (SPI), Standard Precipitation Evaporationtranspiration Index (SPEI), Standard Soil Moisture Index of the two upper soil layers (SSI1 and SSI2), Standard multivariable Drought Index including; MSDI1 based on precipitation and reference evapotranspiration (P&ETref), MSDI2 based on precipitation and soil moisture in the first soil layer (P&SM1) and MSDI3 based on precipitation and soil moisture in the second soil layer (P&SM2) in different climates of Iran (coastal wet, mountain, semi mountain, semi desert, desert and coastal desert) during the years 1980-2020. The results showed that the climatic variables of precipitation have no significant relationship with the increase in GHG emissions in different climates of Iran. If the ETref values during the years investigated in this study showed a significant trend. Also, the highest GHG emissions in 2019 were reported as equal to 443 million tons, and the highest GHG emissions were related to electric energy (47.1%) and nitrogen fertilizer (25.75%), respectively. Also, the evaluation of the effectiveness of drought indices for monitoring the effect of climate on GHG emissions showed a better display of SPI, SPEI and MSDI1 indices. The ability to calculate these indices in different time scales makes the effects of drought to be defined more accurately than using indices without this feature.

Improving water productivity in agricultural productions is one of the fundamental plans in food security in Iran. Because of the importance and vast cultivation of bean in Ahar plain; and the necessity of improving water productivity in the saline soil and water conditions, the current study was conducted with the objective of the evaluation of the effects of irrigation systems and leaching ratio scenarios on bean water productivity in this plain. Bean yields with consumed water under two irrigation systems of surface and sprinkle were directly measured in several farms under farmers' management without any irrigation scheduling. For irrigation systems, five leaching ratio scenarios of 0, 5%, 10%, 15% and 20% of net water were applied in this study. Results revealed that irrigation systems treatments caused different yields and water applied in bean farms. Bean yield averaged 1189±395 kg ha-1 with sprinkle system (probably with deficit irrigation), while averaged 2396±180 kg ha-1 with surface irrigation system. Water applied averaged 4717±747 and 7297±1276 m3 ha-1 with sprinkle and surface irrigation systems, respectively. Water productivity was acquired to be 0.29 kg m-3. Also, we found that leaching ratio scenarios of 0 and 5% had a similar productivity (= 0.47 kg m-3), 10% and 15% produced a similar productivity (= 0.35 kg m-3) and leaching ratio scenarios of 20% had a productivity of 0.22 kg m-3. In addition to these findings, some suggestions were made to continue research and study to improve water productivity in bean production.

Due to the limited water resources of the country and the drought in the past years, the use of modern irrigation systems in order to optimal use of applied water and increase of water productivity has grown significantly and Extensive research has been done in this regard. Therefore, the results of the studies conducted in relation to different irrigation systems of wheat cultivation were collected and analyzed by using of meta-analysis method. OpenMEE software was used for data analysis. The effect size of water consumption in drip and sprinkler irrigation systems compared to surface irrigation system was determined as -3.498 and -3.458, respectively, which according to Cohen's classification, have high effectiveness. Also, the results of meta-analysis showed that the use of drip and sprinkler irrigation systems compared to surface irrigation method has reduced the amount of water consumption by 21.9% and 23.1%, respectively. Although there was no significant difference in the amount of water used in both drip and sprinkler irrigation systems, but drip irrigation increased the crop yield compared to the surface irrigation system. Drip irrigation system was more effective on crop yield (0.914) compared to surface irrigation system. But the effect of the rain irrigation system compared to the surface irrigation system on the yield increase was insignificant. The results of meta-analysis showed that drip (Tape) irrigation method and sprinkler irrigation method increased 39.4% and 31.1% in water productivity compared to surface irrigation system in wheat crop, respectively.

In this study, the groundwater level of Aspas Plain, located in the northwest of the catchment area of Tashk and Bakhtegan Lakes in Fars province, was simulated using the data of 39 piezometers in the aquifer plain in the period of 2001-2017. In this regard, K-Star and ANN models with 1, 2 and 3 lags were used in two phases of training and testing. ANN model in this study was also investigated with the number of hidden layers and different neurons in addition to the mentioned lags. According to the drop and fluctuations of the groundwater level in the mentioned statistical period, the studied aquifer was divided into 4 regions a, b, c and d. The results of the simulation of the groundwater level in area “a” showed that the K-Star model with 2 lags performed better than the ANN model in different lags. But in the other three regions, the ANN model with a lag-1 has provided the best performance. ANN model with 2 hidden layers and 4 neurons in region b, with 2 hidden layers and 6 neurons in region c, and with 4 hidden layers and 5 neurons in region d were introduced as the best model for simulating groundwater level values. On average, the best models introduced in regions b, c and d were able to improve the error rate by 57, 42 and 81%, respectively, compared to the K-Star model. The poor performance of the K-Star model in two regions b and d is also clearly visible. In general, the results showed that lag-1 of the ANN model had the best performance in simulating the values of the groundwater level in the three regions b, c and d with the number of hidden layers and different neurons.

The optimal and sustainable application of groundwater resources in east the Urmia Lake is essential and important from the view point of water resource management. Quantifying the current and projecting consumption are the first step for the initiation of sustainable utilization of groundwater. Due to the potential of modeling and projecting behavior of phenomena in water engineering, this study aimed to analyze the fluctuation of groundwater level in the east of the Urmia Lake. In this study, groundwater levels for 45 years with methods of genetic expression programming (GEP) and time series (TS) were modeled and evaluated. Groundwater level data during 1986-2021 was applied for modeling and testing; during 2022-2031 applied for future study, respectively. Then, the model of GEP with three genes was recognized as the most appropriate model. Evaluation criterion for optimum model were as RMSE= 0.26, MSE= 0.07, RAE= 0.58, RSE=0.26, RRSE=0.52, r=0.87 and R2= 0.76. Results showed that since 1986, the groundwater level was reduced about 11.2 m. Several scenarios for groundwater balancing scenarios starting from 2021 were considered to reduce the effects of the decreasing trend of water level and optimal management of groundwater consumption. Relative to the 1986, the cumulative reduction of the water levels at the end of year 1410 will be 12.6 m in case of current trend of consumption; and 11.4m, 10.7 m, 10.1 m in case of water balancing as 10%, 15% and 20%, respectively. Improving cultivation patterns with crops having relatively low water requirement, leveling of lands and suitable deficit-irrigation scheduling are the solutions that could balance the water levels in the region.

In current study, effect of model WLH (Wide low head) and NLH (Narrow low head) fusegate’s location on hydraulic characteristics of flow were investigated. scale models of standard WLH and NLH type fusegates were made respectively in 16.7 and 25 cm height with five different inlet wells heights and located in the middle and end of the laboratory flume and it was tested and the values of different flow discharge and corresponding upstream heads were recorded and the discharge coefficients value were calculated. Results showed that in a certain model of fusegate, the discharge coefficient is a function of the ratio h/H (the ratio of the water height on the fusegate to the height of the fusegate) and with the increase of the water height above the fusegate, the value of the discharge coefficient decreases exponentially. Discharge coefficient of fusegate located in the end of channel is more than located in middle of channel (Due to the reduction of the limiting effect of the channel wall), and difference in the value of the discharge coefficient in WLH fusegate is more. Using 80% of the data, appropriate relationships were proposed for estimating the discharge coefficient. This relationships were validated using the remaining 20% of the data. The statistical parameters show the high accuracy of this relationships in estimating the discharge coefficient.

The main difference between compound sections and simple sections in channels is due to the velocity difference between the floodplain and the main channel. This velocity change ultimately causes changes in the shear stress distribution of the bed canal. The structure of flow turbulence in compound channels is complex due to the combination of boundary shear stress and Reynolds stress near the interface of the floodplain and the main channel .Due to the fact that the flow hydraulics in rivers, which are considered to be a type of compound channel, depends on their shape and the changes in canal shape are dependent on bed shear stress, determining the distribution of bed shear stress in rivers is also of great importance. In this study, the boundary shear stress distribution in compound channels has been simulated with 2 numerical models of Fluent and Flow-3D software and compared with real experimental data (Wallingford, England), as well as a comparison between the output results of the shear stress distribution in the compound section is also performed based on the YLM method. To verify the accuracy of the simulation results, 3 methods of determining the convergence (error parameter) have been used to compare the computational results with the experimental results. The results showed that there was a very good match between the results of the numerical models and the experimental data, and as a result, both software could calculate the shear stress distribution appropriately. Generally, the numerical results of fluent software were closer to the experimental data compared to Flow 3D software.

The lack of water and food supply makes deficit irrigation will be an unavoidable and widespread action in all aspects of agriculture, especially in high density orchard which aims to increase the quantity and quality of the product, it increases the consumption of water and other inputs. Water productivity is an indicator that shows the product produced per irrigation water consumption. Apple is considered as one of the most important garden and agricultural export products of the country. Recently, apple gardeners are increasingly using shade nets to deal with weather hazards, so this study was conducted to investigate the effect of deficit irrigation and shade nets on water productivity and the quantity and quality of apple fruit.The present research was conducted in the high density apple orchard (cv. Golden Delicious) of Astan Quds Razavi sample farm during during 2021, which was set up as a split plot experiment based on a randomized complete block design (the main plot of irrigation treatments: Full Irrigation treatment (FI),Regular Deficit Irrigation treatment(RDI) and Sustained Deficit Irrigation (SDI) and sub plot: presence (S) and absence(N) of shade net) with four replications.According to the results obtained from this research, (RDI) reduced water consumption by 15% ,7% yield and 3% fruit growth. While the water productivity, firmness, maturity index, total sugar, antioxidant and total phenol increased compared to the control treatment and did not change the fruit juice, also the presence(S) of shade net reduced water consumption by 14% and It has increased yield by 9%. Despite reducing irrigation water consumption by 40%, having the highest amount of water productivity and improving some physicochemical characteristics, sustained deficit irrigation (SDI) severely reduced fruit weight, fruit growth and yield.

Mulberry leaves are the only nutrition of silkworms and the quality and quantity of mulberry leaves can directly affect the resulting silk. A study was conducted from June to September 2020 to investigate the effect of surface and sprinkle irrigation methods in comparison with rainfed on the quantity and quality of mulberry leaves and silkworm cocoons in the National Silk Research Center located in Pasikhan, Rasht. Four irrigation treatments including manual sprinkle irrigation (I2), smart sprinkle irrigation (I3), and surface irrigation (I4) versus rainfed cultivation (I1) were compared. The results of variance analysis showed that there was a significant difference between treatments. Mean comparison showed that the highest number of leaves per branch, leaf weight, leaf moisture content, and the ratio of number of leaves to branch length were 87.86, 84.6 gr, 45.67%, and 0.461, respectively, obtained in manual sprinkle irrigation. Manual sprinkle irrigation had the highest yield as compared to other treatments (766.7 gr/tree and 6314.3 kg/ha). The highest branch length was obtained in surface irrigation treatment with 202.7 cm. Statistically, at the level of 5%, smart sprinkle irrigation treatment was not significantly different from manual sprinkle irrigation. The amount of water used in smart sprinkle irrigation treatment was less than that of manual sprinkle irrigation, and therefore water productivity and electricity energy efficiency (kg/kWh) were higher, being 7.24 kg/m3 and 47.1 kg/kWh, respectively. The results showed that irrigation of mulberry orchard can save the plant from water stress and increase yield. Manual sprinkle irrigation has the highest positive effect on the quantity and quality of mulberry leaves and using a smart system can increase water productivity and play an important role in reducing water consumption.

Soybean is considered as one of the valuable crops in terms of providing food, which has high amounts of protein and oil. This crop is sensitive to the amount of irrigation water. For this reason, it is suggested to determine the appropriate irrigation period along with the use of superabsorbent. To optimize these factors, the response-surface method was used in the present study. For this purpose, the soybean data collected from a research farm located in the Research Institute of Agricultural Engineering, in Iran, in 2018, was used. Two factors of irrigation period (with high and low levels of 4 and 7 days, respectively) and amount of superabsorbent (with high and low levels of 300 and 0 kg.ha-1, respectively) were applied. The results showed that the response surface method had an overestimation error (MBE>0) for predicting oil yield, and an underestimation error (MBE<0) for predicting other yield and yield components. The accuracy of this model for predicting all parameters were excellent (NRMSE<0.1) and its error was acceptable (RMSE<3%). The optimization results showed that seed yield, oil yield, protein yield, number of pods, plant height and water productivity were 169, 228, 227, 89, 34 and 131% higher than the average observed values of these parameters. In order to achieve optimal values, it is necessary to reduce the irrigation period to three days and use the amount of superabsorbent up to 50 kg.ha-1. Therefore, compliance with this issue is suggested for soybean cultivation.