نشریه فناوری های پیشرفته در بهره وری آب
سال سوم شماره 1 (بهار 1402)

Currently oilseeds are of particular importance among crops and constitute the second food reserve in the world after cereals. Camelina is a new oil plant with a short growth period and good resistance to drought stress, pests and plant diseases and cold, which can play a role in oil production. This study was conducted to investigate the effect of sowing date and nitrogen fertilizer on growth and yield of Camelina in irrigated farms conditions under Kermanshah city climate in 2019-2020. A split plots experiment was conducted based on randomized complete blocks design with three replications at the experimental field of Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran. The main factor was sowing dates (early November, mid-November and late November) and the sub factor was nitrogen fertilizer application (0, 100, 200, 300 kg ha-1). The results showed sowing date treatment had no significant effect on most of evaluated characteristics. The highest water use efficiency of grain (0.96 kg/mm) and grain oil (0.15 kg/mm) in treatment of 100 kg of urea he-1 and the highest water use efficiency of grain protein (0.23 kg/mm) and total protein (0.53 kg/mm) was observed in treatment of 300 kg of urea he-1. In general, the results showed that sowing date had no effect on water productivity of evaluated traits, however, use of 100 kg of urea he-1 due to higher water efficiency, along with the benefits of preventing environmental hazards, due to the improvement of most of the examined characteristics, it is recommended.

Pressure management and reduction of high pressures are necessary to reduce leakage and extend the life of water distribution network equipment. There is a need for a benchmark and indicator to compare the distribution network pressure management. Investigation of the presented indicators shows that the reliability index is a suitable criterion for evaluating pressure management. In this research, using optimization methods, pressure reducing valves and changing the diameter of the pipe, the possibility of increasing the reliability of Javanrood water distribution network was investigated. In this study, using single-objective and two-objective optimization algorithms, the position and settings of pressure relief valves were determined for this network. In the single-objective Harmony Search algorithm, network reliability was considered, and in the two-objective algorithm, pressure and velocity reliability were considered as the objective functions. The results showed that the single-objective algorithm has increased the reliability of the network by 17% and the two-objective algorithm by 14% compared to the current situation. Examining the changes of network reliability in 24 hours of the day shows that the network reliability values obtained from the two-objective algorithm had very little fluctuations compared to the single-objective algorithm. In other words, the reliability of the network has been almost constant throughout the day.

The study was conducted to simulate the effects of climate change on maize growth, production and water productivity. The evaluated factors included solar radiation, temperature, water consumption and evapotranspiration. The CERES-Maize model was used to simulate the evaluated characteristics. The results of GCM showed according to RCP4.5 and RCP8.5 scenarios, total radiation from 3418 under baseline conditions, will reach to 3983 and 3984 for near future period and 4006 and 4023 MJ/m2 for far future period, respectively. Under basal condition, average temperature was 22°C which based on RCP4.5 and RCP8.5, it will increase 2.3% and 4.3% in near future, and 8.5% and 17.2% in far future, respectively. Water consumed, water use efficiency and evapotranspiration in near climate change in RCP4.5 varied as 9.1, -5.4 and 7.7 -0.18 % and in RCP8.5 varied as, 9.2, -11.6 and 6.7% compared to baseline conditions, respectively. These values for RCP4.5 in far climate change were 9.7, -23.7 and 6.9% and for RCP8.5 were 10.1, -50.7 and 5.7%, respectively. Regarding to effect of sowing date, in climate change condition, by sowing the studied cultivars at late dates compared to the early dates and common date, water use efficiency was improved. Among the studied cultivars, Simon cultivar had the highest water use efficiency. In general, according to results, sowing of Simon cultivar in May 25 which had the highest water use efficiency, it can suggest as a suitable strategy to reduce the negative effects of climate change on maize production in Kermanshah region.

Considering that pontoon breakwaters are among the most common floating breakwaters, which have many advantages over other types of fixed breakwaters, therefore, in the present study, the performance of the rectangular section of this structure under the conditions of Caspian Sea waves has been studied. In this study, ANSYS AQWA software was used, and the analyzes were carried out in the form of hydrostatic analysis and time history analysis by applying the 20-year average wave conditions of the region and time history analysis under the conditions of regional limit waves. In order to validate and calibrate the model, McCartney's 1985 laboratory data has been used. The results of the research show that in the conditions of hydrostatic analysis, the highest amount of displacement occurred in the Heave movement and the lowest amount of displacement occurred in the Surge movement, which is very insignificant. The displacement in Heave movement under the wave period of 6 seconds has the highest value (1.6142 m) and the lowest value in the period of 2 seconds. Also, in the same condition, the analysis of the amount of rotation around the Z and Y axes is very small compared to the rotation around the X axis. Even the maximum values of the rotation around the Y and Z axes are less than the minimum rotation around the X axis with a value of 6.7504e-05 (°/m) which occurs in a period of 2 seconds.

The measurement of the permeable water pressure, the flow rate of leakage and drainage from the beginning of the construction of the rockfill dam are the most important characteristics needed in analysis these dams. Failure to control the above parameters can cause the waste of water stored in the reservoir, threaten the safety of the dam, and also reduce the stability of the dam through piping or liquefaction. Rockfil1 dams are used to prevent seepage, store water, control floods and delay floods. The problem of leakage should be controlled and limited in such a way as to prevent the creation of adverse effects such as: loss of water stored behind the earthen structure, creation of pore pressure in the porous medium, reduction of the effective stress between soil particles and, as a result, reduction prevent its shear resistance. In many cases, rockfill dam meets the needs of the project, because gravel is far more stable than soil and its ability to be washed is less. The slopes of the gravel dam body are steeper than many other soils, which saves money. In the present research, gravel materials were first prepared from the river mines of Khuzestan province to conduct experiments. These materials were used in three sizes with an average diameter of 10, 20 and 30 mm respectively to make the model. In this research, it was tried to study the leakage parameters in the gravel dam by building a physical model. A physical model of a gravel dam was built in a laboratory flume with three gravel samples and three slopes with the aim of investigating and determining the amount of leakage from the dam body. Pore pressure was measured with piezometers installed in the flume body. The results of the research showed that in a constant slope, the flow-field angle increases as the flow depth increases. Also, with the increase of the flow rate and the increase of the diameter of the particles, the depth of the outlet flow is reduced and these changes are not clear at low flow rates, but are clearly visible at high flow rates. In constant diameter and flow rate, with the increase of the slope of the model, the depth of the outlet flow decreases, and in the constant flow rate, with the increase of the ratio (Bc/H), the value of the outlet height of the flow decreases. Based on the experiments, the following results are presented. In the ratio of Bc/H = 1, with the increase of upstream depth, the depth of outflow has increased. Considering that the depth of the outlet flow downstream can be determined using the concept of the flow-field angle, it can be said that the depth of the outlet flow increases with the increase of the flow-field angle. In the ratio Bc/H=2, with the increase in the width of the model, the depth of the outlet flow has decreased compared to Bc/H=1. In addition, it can be concluded that in a constant slope, with the increase in flow depth, flow-field angle increases. Also, with the increase in the diameter of the particles, the depth of the outflow decreases. These changes are not clear at low flow rates but are clearly visible at high flow rates.

In recent years, one of the most suitable options for saving water resources is the recycling of urban and industrial wastewater for irrigation which is common practice in different parts of the world, but if the use of wastewater Sewage can not be managed properly for irrigation, which may cause environmental problems. the purpose of this study was to investigate the effects of long-term irrigation with municipal treated wastewater (TWW) compared to well water (WEW) as a control treatment on soil chemical in three layer with three replications in a two-year split plot trial design was performed. in three It has been repeated. due to the availability of this source and the possibility of leaching, the risk of saltinification of this land has been somewhat overcome. the risk of sodiumization of this land has led to the fact that, due to the high clay content of this land, its future consequences include traps and reduced permeability. Irrigation with TWW resulted in a significant increase of 0.3 units of pH in irrigated soils with wastewater compared to WEW. The TN content varied between %11.30 and %25, which indicates the variable percentages of this parameter at the region of the study area. Also, the results of soil organic carbon (OC) changes as a result of irrigation with TWW showed that this irrigation effect was significant and increased by 55% for irrigation compared to treatments irrigation with WEW due to Organic contents in the wastewater.