نشریه رویکردهای نوین در مهندسی آب و محیط زیست
پیاپی 1 (بهار و تابستان 1401)

The combination of phytoremediation and porous concrete is a new technology used as a natural purification of porous concrete and resistant plants to remove or reduce the concentration of pollutants. In this study, the performance of porous concrete as a bed and plant on reduction of urban effluent pollution has been investigated. A channel with dimensions of 9 meters length, 30 cm wide and 20 cm height was constructed along with the wastewater treatment lagoon of Isfahan University of Technology. Then, blocks were made of porous concrete with dimensions of 30 × 30 × 15 cm, and placed in the channel. The vetiver grass with two different densities (12 and 27 plants) were placed between the porous concrete blocks. After 5, 7 and 9 hours, the wastewater samples were taken from the inlet and outlet basins. The reduction of BOD, COD, TSS and total coliform during the 5 hours retention time, were 16.1, 27.5, 20.6, and 19.1 percent, respectively. In the retention time of 7 hours, reduction were equal to 20.5, 33, 26.1 and 25.3 percent, respectively. The reduction of BOD, COD, TSS and total coliform during the 9 hours retention time, were 25.9, 38.5, 31.9 and 30.5 percent, respectively. In general, this research showed the performance of system was optimistic in reduction of BOD, COD, TSS and Total coliform

In rivers and especially in river bends, the variation of stream-wise flow velocity in width and depth directions is non-uniform and is affected by many factors including secondary flows, bed and bank roughness, and flow hydraulic characteristics. For calculation of two-dimensional flow velocity distributions in straight rivers many approaches have been presented by researchers, while in meandering rivers, due to the complex mechanism of flow pattern, the solution of velocity field is carried out by computational fluid dynamics software packages. In this research, the Chiu's probabilistic theory was used for solution of the flow velocity field in a river bend on the Gorganrood located in Goletsan province. Considering the lack of measured point velocity data in river bends, 6 field measurement series were collected in one of bends located about 200 m upstream of Aghghala hydrometric station. Among these measurements, 4 series are selected for the model calibration and 2 remaining series for the model validation. The results showed that the Chiu's method has an acceptable accuracy in simulation of flow velocity fields for river bend. The statistical measures for the obtained point velocities indicated that the mean errors of this method are 4.9 and 3.5% in the calibration and validation phases, respectively. The mean errors for the calculation of total flow discharges are 5.9 and 6.0% respectively.

In recent years, unnecessary exploitation of water resources, especially groundwater resources, droughts, lack of protection in the use of water resources, population growth, etc. has led to water input as one of the most important. The most limiting factors of development should play a role in the agricultural sector. One of the ways that can some extent solve this problem is comprehensive water management, which is an important economic method and values can be balanced between supply and water demand. In this study, the production function method was used to determine the economic value of water in the production of wheat and barley products. EXCEL and SPSS software were used to analyze the data. The obtained results showed that the average amount of final production of irrigation water input for wheat and barley crop is equal to 0.240 and 0.268, respectively, with economic value of 3223.3 and 2813 Rials per cubic meter. Also, the highest water consumption in wheat and barley production was equal to 5200 cubic meters and 3100 cubic meters, respectively, and the average water consumption was equal to 4604.56 and 2793.7 cubic meters, respectively. Due to the fact that the final value of water production is more than the cost of irrigation water supply, if the price of agricultural water is not corrected, it will lead to improper harvesting and use of water resources. To prevent this, it is better to set the price of agricultural water based on the final value of production.

The Center pivot system is one of the most advanced sprinkler irrigation systems that recently has been used in Iran. According to this research on the compatibility of the system with the cultural, economic, climate and optimization performance of the system is essential. The importance of this matter on one side and the lack of information on the other hand, it highlights the need for an investigation. In this regard, the evaluation of the Center pivot system in two speeds 10 and 60 percent took a radial and vertical. The uniformity coefficient (CU) in the radial arrangement of cans and in two speeds 10 and 60 % was 80.3 and 76.4%, respectively and the uniformity of water distribution (DU) was 72.6 and 65.5 respectively. Also the uniformity coefficient (CU) in the vertical arrangement of cans and in the same speed was 61.1 and 59.3 % respectively. Uniform distribution of moisture in the soil after irrigation with rate of 60% was 86.37 percent. So the amount of Uniform distribution of moisture in the soil was higher than the uniformity coefficient in the Surface Soil (CU). The main reason is the horizontal flow and water transfer in the soil and its influencing factors (Mass flow, Diffusion and Hydrodynamic dispersion). According to this and given the lack of available water resources in arid and semi-arid area, maybe there is no need to increase water of irrigation in order to increase the uniformity of water distribution to more than 70 percent

The crop evapotranspiration (ET) has spatial and temporal variations within the region due to changes in meteorological parameters, phenological stage, and farm management conditions. The main objective of the present study was to compare the trend of temporal and spatial variations of grain maize evapotranspiration in Mahidasht using satellite images with available resources (due to lack of Lysimeteric data). In this study, the daily evapotranspiration for the four maize farms in the different parts of the plain was calculated using Landsat 8 satellite images and the SEBAL algorithm on six dates during the growing period of maize in the year 2014. Since there was no field measurement of ET to verify the results of estimated ET based on the SEBAL algorithm, the final results (evapotranspiration) and intermediate results (Land surface temperature, Albedo, and NDVI) calculated by the SEBAL algorithm were compared with acceptable values in the literature. Results showed a similar trend of estimated evapotranspiration by the SEBAL algorithm and AGWAT software. The trend of increasing and decreasing land surface temperature was rational. The average of NDVI during the growth period in the studied farms was between 0.47 and 0.53 which was acceptable. Albedo with an average of 0.17-0.18 had slight variations between the selected farms. Results showed rising in land surface temperature, evapotranspiration, and NDVI to the middle of the growth period and then reducing of these parameters. The average estimated maize evapotranspiration based on the SEBAL algorithm was between 3.35 to 8.53 mm/day for the six imagery dates.

It is so vital to note the cultivation of rice because of its high irrigation water consumption. This crop is the most important food source in the Iran, hence, it is necessary to know how much irrigation water must be used to grow different rice cultivars under various cultivation types. On the other hand, applying farm tests to achieve the goal need high costs and waste much time. Regarding that, it is necessary to use crop modeling. In this study, AquaCrop was used to simulate yield, biomass and water use efficiency of rice. The research was conducted at Khuzistan Agricultrual Research Station. In this study, three types of cultivation (D1: transplanting, D2: current directs seeding consorted seeding, and D3: dry bed seeding) and rice cultivars (V1: Red-Anbori, V2: Champa, V3: Danial) were considered to simulate abovementioned parameters. MBE, RMSE and NRMSE values for seed yield were 0.25 ton.ha-1, 1.0 ton.ha-1 and 0.1, respectively. Those values for biomass were 0.3 ton.ha-1, 1.15 ton.ha-1 and 0.05, respectively, and for water use efficiency were 0.07 kg.m-3, 0.24 kg.m-3 and 0.03, respectively. EF values for seed yield, biomass and water use efficiency were 0.87, 0.56 and 0.65, respectively, and d values for all parameters were equal to 0.99. Regarding the results, AquaCrop had good accuracy for simulation of rice yield, biomass and water use efficiency.

Today, the effects of climate change and global warming have been proven due to the increase in greenhouse gases in the world. In this research, the monthly values of temperature, precipitation and discharge of Jamishan Dam in the years 1988-2017 have been considered as the base period. Simulation of resources and uses of the jamishan Dam catchment area was investigated using the WEAP model with different cultivation patterns in the area. To evaluate the effect of climate change on precipitation and temperature parameters in this region, RCP8.5 scenario outputs of HADGEM2_ES and MIROC5 models and a series of CMIP5 reporting models were used and the output of these models was downscaled for the region. In this research, change factor method used for downscaling and the monthly temperature and precipitation parameters of Jamishan Dam were produced for the period 2021-2050. In order to study the runoff of the region due to climate change, the SVR model was studied. The results of the climate model show an average temperature increase of 0.5 to 1 ° C. The simulated rainfall results show that the average monthly rainfall under the RCP8.5 scenario in the future period in HADGEM2_ES model increased by 1.3% and in MIROC5 model decreased by 6% compared to the base period. Examination of the results of discharge forecast in SVR method indicates that runoff is associated with a decrease compared to the base period.Simulation of different cultivation patterns in WEAP shows that the average supply is 70% in the SVR method.

The devastating flood of Karkheh River in 2019 besides changes of morphology and conditions of the river bed after operation of the dam warn the experts to double check stability of Karkheh (Hamidieh) Diversion Dam to assure that the dam is in good conditions. Great accuracy and simplicity of mathematical models, besides the easy access they provide to the results and data analyses, makes them a suitable alternative for the empirical methods. The present study is an attempt to use HES-RAS and SAP software to analyze the effect of upstream morphological changes on stability of Karkheh Diversion Dam. The results suggest that structure of Hamidieh Regulatory-Diversion Dam is conveniently stable and the models are indicative of proper stability factors. According to the results, safety factors of the stability of Hamidieh Dam against sliding of the middle pier under normal and special loads are 1.51 and 6.93 respectively. Considering the age of Hamidieh Dam and wears and damages observed on its hydraulic structures, further studies on curing and repair of this dam are recommended. The results suggest that stresses applied to the lower parts of the weir are slightly larger than the allowable rang.

Flood assessment and forecasting its potential volume is one of the main problems of catchment managers, which needs more cooperation from flood forecasters, users, managers and water users in the region to prevent financial and human losses. The purpose of this study is to provide an appropriate solution to establish a flood forecasting system based on the cooperation of model developers, users and managers in order to improve management and reduce flood damage. In this study, to predict the flow in 5 basins of Karun 4 Dam, Seymareh Dam, Rudbar Dam, Sardasht Dam and Azad during seven years, meteorological maps of two models, COLA and WRF, were used to predict precipitation. The developed NAM simulation model led to forecasting floods in the coming days of the basin and reducing financial and human losses. The results of the reports indicate that 70% of the forecasts are in the observational flood range.

Predicting the extent of local scouring downstream of hydraulic structures has been one of the topics of interest to researchers in recent years. In this research, downstream scouring of a trapezoidal piano key weir under changes in the hydraulic conditions of the flow and the height of the flow drop passing through the weir in a channel with a length of 10 meters and a width and height of 0.75 and 0.80 meters in the hydraulic laboratory of Water Engineering Group. And hydraulic structures of Tarbiat Modares University of Tehran have been studied. Uniform and non-sticky sediments with an average diameter of 2 mm in length and width of 3 and 0.75 m downstream of the piano key weir were used. All experiments were performed under free flow conditions. The results showed that the maximum occurrence of scour depth with increasing flow drop height is farther away from the weir. The maximum scour depth increases with increasing flow drop height. Scouring in the transverse middle of the bed is less than its walls. Increasing the height of the flow drop is accompanied by more changes in the topography of the bed.

The water infiltration into the soil is one of the main components of the hydrological cycle, which is very important in various topics. Therefore, it is necessary to evaluate different methods of estimating it. In this study, 11 points in different regions of Lorestan province were selected and the methods of Kastyakov, modified Kastyakov, Philip and SCS were evaluated. also, Infiltration measured using a dual loop at these points. The results showed that the Kastyakov model for the regions: Sarnaveh, Kuhdasht, Poldakhtar, Jojeh Heydar and Doroud, the SCS model for the regions: Azna, Dehpahlavan, Sarnamak and Aznasagvand and the Philip model for the Khayan and Kioreh regions have the most accurate compared to the observational data. Based on the analysis of variance, the amount of infiltration estimated by all 4 methods was not significantly different from the amount of field infiltration. In general, it can be said that in most of the studied areas, the performance of the Kastyakov model was acceptable and the performance of the SCS model was poor.

It is important to know about the deserts of Iran because the geographical and climatic conditions of the desert have never been expanding by themselves. What expands deserts is the relationship that desert areas have with their surrounding environment. Climate change during the last few decades has caused climatic hazards in desert areas to cause a lot of human and financial losses. The purpose of this research is the spatial planning of climatic hazards in order to reduce their damages in desert areas. This research is descriptive-analytical in terms of applied method. At first, the most important climate hazards in desert areas were identified. Then, using the opinion of experts and interviewing them, the most important criteria and strategies to reduce the damages of climate hazards in desert areas were identified. The results showed that drought, increase in temperature intensity, heavy and short-term rainfall, frost, dust storms, and floods were identified as the most important climatic hazards during the past few years. In this research, cost-benefit, people's participation, technological and scientific tools available, political and social pressures, appropriateness and compatibility with the environment, traditional management and indigenous knowledge, government oil revenues, temporary managements, problems related to innovation and changing methods, The convenience of government administrative systems is a factor, and time, the beauty of the landscape, expert human resources, and emergency issues caused by climate hazards are considered as handicaps. The results show that the approval of a new and comprehensive law related to climate risks is the most important