نشریه پژوهش های نوین در مهندسی آب پایدار
سال دوم شماره 1 (پیاپی 3، بهار و تابستان 1402)

Obtaining appropriate and accurate methods in predicting the sediment load of rivers is of particular importance due to its negative effects on water quality indicators, reducing the capacity of reservoirs and changing the morphology of rivers. Also, the suspended sediment load in rivers is usually determined by hydrological methods. The aim of the present research is to link the suspended sediment load to the hydraulic-hydrological-morphological parameters of the river. To achieve this goal, dimensional analysis method was used. The measured data from two hydrometric stations on the Barandoz River-Urmia Lake basin were used to extract non-linear relationships in predicting the suspended sediment load. The evaluation of the estimated values of the new relationship revealed that the final presented equation has a 25% error in estimating the suspended sediment load compared to measured data, which indicates the appropriate accuracy in estimating the sediment load in rivers.

In the discussion of flood management, the use of embankment plug fuses and dams is considered very important. The embankment plug fuse prevents the sudden overtopping of dams against sudden floods and allows the discharge of excess flows during floods. Gives. In this research, with the experimental modeling of a homogeneous embankment fuse plug, with the aim of investigating the destruction of the embankment plug fuse structure and how the breach in it expands due to the current passing through as a result of the change in the dimensions of the pilot channel, the rate of increase of the water height behind the structure and the change in height. A total of 36 tests were conducted and their degradation characteristics were analyzed. 3D analysis of the breach in embankment plug after passing water through it was done, and these analyzes include the crack expansion rate, the shape of the breach, and the way the breach expands. The results obtained from the gap analysis showed that the plug fuse destruction process takes place in 3 stages. Also, the duration of complete splitting between 40 and 55 seconds was measured in different modes. The results of the examination of the breach-opening rate showed that in about 20 seconds, a turning point can be seen in the graphs, which indicates a decrease in the opening rate in the second stage due to the undermining process around the pilot channel.

Animal manure is used to increase the productivity of agricultural products and improve soil properties. Pathogenic microorganisms present in animal manure cause environmental pollution. Therefore, it is necessary to investigate the effect of cattle manure granulation on physical characteristics such as hydraulic conductivity and hydrophobicity of manure in order to be a basis for other researches on water and soil pollution. The aim of this research is to investigate the effect of cow manure size on saturation hydraulic conductivity and hydrophobicity of cow manure. For this purpose, four granulation treatments were prepared (D1-1-2, D2-0.5-1, D3-0.25-0.5 and D4>0.25 mm smaller). Saturated hydraulic conductivity was done by constant load method and water repellency test was done by water drop penetration time method. The obtained results showed that by reducing the size of cow dung particles, saturated hydraulic conductivity decreases significantly at a statistical level of 1%. Respectively, the highest and lowest saturation hydraulic conductivity was related to treatment D4 with hydraulic conductivity of 1.6 cm/min and D1 with hydraulic conductivity of 0.063 cm/min. The reason for this is to reduce the pore size in small grains. Reducing the particle size of cow dung increases water repellency. The highest and lowest degree of water repellency is related to treatment D1 and treatment D4, respectively. The reason for this is the presence of microbial particles rich in fatty acids in smaller granulation treatments. It seems that the use of coarse-grained cow manure in agriculture is a more appropriate option than fine-grained cow manure due to its higher hydraulic conductivity and lack of hydrophobicity.

Drought is a natural and reversible feature of climate and can affect almost all climate zones with any climate. The aim of this research is to investigate the upcoming obstacles in the formation of water harvesting organizations as a solution for the optimal use of existing water resources in order to prevent excessive water consumption with the participation of stakeholders. Water catchment organizations are the first form of cooperative management approach in the irrigation sector and their key role in the optimal management of agricultural water consumption is undeniable. In this study, three established pilot organizations in the area of ​​Sefidroud irrigation network were used to investigate the upcoming obstacles in the formation of water harvesting organizations. The statistical population of the members of water bodies in Sefidroud basin was defined, and the formation process of the organizations was investigated using a questionnaire with a Cronbach's alpha coefficient of 0.9, 62 items, through the active questioning method. The results showed that the formation of organizations can create a positive trend in improving the conditions of the aquifers. According to the obtained results, the most effective index is related to social indicators with a weight of 0.312, sustainability index with a weight of 0.298 and communication with a weight of 0.211, and the least effective indicators are related to the definition of tasks index with a weight of 0.13 and time index. showed with a weight of 0.14. It is also possible to use organizations as a pilot in areas that have the capacity and conditions to accept the plan, and by having a successful example, encourage other farmers to participate in the formation of organizations.

Banana growing areas are located in subtropical climates between 20 and 30 degrees north or south of the equator. Considering that Sistan and Baluchistan province is located in the latitude of 25 to 31 degrees north, it can be suitable for banana cultivation. In this regard, the main goal of this research is to identify the climatic potential of Sistan and Baluchistan province for banana tree cultivation using agroclimatic indices. In this study, two methods of AHP and Boolean logic of the province's climate were used to evaluate the agroclimatic indices including growing degree days (GDD), biologically effective degree days (BEDD), sum of active temperatures (SAM), cumulative temperature difference (TD), water vapour pressure deficit (WVPD), and potential evapotranspiration (PET). The results of the research showed that with the AHP method, 17% of the area of the province (Dashtiari, Chabahar, Konarak and Zarabad cities and parts of the south of Rask, Qasrqand and Nikshahr cities) is very suitable for banana cultivation and 8% is suitable for banana cultivation (northern half of Sarbaz, Rask and Nikshahr counties). Also, the results of this research showed that in Bolin logic, 10% of the studied area (Dashtiari, Chabahar, Konarak and Zarabad cities and parts of the south of Rask, Qasrqand and Nikshahr cities) are suitable for banana tree cultivation in the province. Currently, banana cultivation areas are less than 1% of the area of the province, which is not consistent with the results of this research. Therefore, based on the results of this research, the areas under banana cultivation in the province can be increased.

Reference evapotranspiration (ET0) is the maximum amount of water transpiration for a particular vegetation cover (such as grass, alfalfa, or a standard crop area). FAO 56 report emphasis, is on measuring meteorological parameters at a height of two meters above green grass. Cultivation around the station should be on a wide area and there is no shortage of water. Agricultural meteorological stations covering a certain territory around them record the same meteorological conditions as the surrounding plants. The Penman-Monteith-FAO (PMFAO) equation was proposed to calculate ET0 and the use of alternative method was not recommended. In the present research, the Hargreaves-Samani (HS) method and the PMFAO method were evaluated on daily, Monthly and yearly time steps in the ZayandehRud basin over a period of 25 years from 1995 to 2019. The results showed that in the daily time step, the difference between the two methods is large (Nash coefficient from 0.63 to 0.87). In the monthly time step, the difference is generally negligible (Nash coefficient from 0.8 to 0.96). In annual time step (Nash coefficient above 0.8), the results are very close to each other. But in different stations, the same behavior was not seen, for example, in Kabutrabad station, in contrast to East Isfahan station, almost always, ET0 by HS method is higher than PMFAO. Therefore, in practice, to use ET0 by HS method, it is recommended to verify and evaluate at least with the nearest synoptic station and PMFAO method and then use it.

Groundwater resources are considered as the second largest fresh water resource of earth after glaciers. Water shortage and lack of proper management of groundwater resources result in droughts and consequent severe water crises around the world as well as Iran. Excessive withdrawal of groundwater from the Minab Aquifer caused that the inlet of the aquifer could not cope with the withdrawal and, as a result, the groundwater level was dropped. Prediction of groundwater flow behavior for optimal management of groundwater resources is one of the objectives of hydrological studies. Thus, the present study considered quantitative and qualitative modeling of the Minab aquifer by using GMS 7.1 which has a special importance in water management. Quantitative modeling of groundwater flow was carried out in MODFLOW code for steady state in October 2002 and for unsteady state during the year of 2002-2003. By calibrating the models, the RMSE and MAE values for determining groundwater levels were estimated as 0.268 and 0.25 meters, respectively. The average annual drop of groundwater level in Minab aquifer was estimated as 0.02 m during a year. The qualitative model of groundwater flow was run for a year period to determine TDS value by using MT3DMS code. After Model calibration, the RMSE and MAE values were estimated as 4.345 ppm and 2.357 ppm. It can be concluded that the current trend of groundwater flow will decrease the groundwater level and increase the aquifer pollution level.

The exploitation system of irrigation and drainage networks can be effective in choosing the type of measurement tool and its exploitation. The selection of flow measurement tools depends on factors such as required accuracy, cost, protection and maintenance requirements, hydraulic considerations, adaptation to operating conditions, etc. The purpose of this research is to compare the practical methods of measuring the hydraulic parameters of flow in irrigation networks in operation in order to determine the most suitable tool for measuring flow. In this research, the flow meter mechanical device (MO), an electronic portable ultrasonic flow meter device equipped with an pressure altimeter (CC) and electronic radar flow meter device equipped with ultrasonic altimeter (OFR) an common and fixed point in the left bank channel of the irrigation and drainage network Mahabad (LMC) were evaluated at three water levels of 0.6, 1 and 1.2 meters. The results showed that the average flow rate changes of MO, CC and OFR measuring instruments at 0.6 and 1 meter levels were about 23%. At the level of 1.2 meters due to the increase in flow volume, the formation of surface waves and the proper flow pattern; the flow rate changes of OFR and CC devices are less than 5%, which shows the acceptable accuracy of both devices based on the nature of the measurement equipment. In addition, it can be acknowledged that the OFR device with periodic calibration by the CC device can be used as a useful tool in measuring the parameters of flow, velocity and water level height.