Showing 2384 results for Type of Study: Research
M. Farzamnia, M. Akbari, M. Heidarisoltanabadi,
Volume 27, Issue 4 (12-2023)
Abstract
The agricultural sector depends largely upon water and energy resources to fulfill sufficient water for producing adequate food for the rapidly growing world’s population. It requires great effort to improve water and energy productivity for agricultural products to provide consumers’ health as well as environmental protection. In this study, the volume of irrigated water, crop yield, water productivity, and the consumed energy for onion crops irrigated with sprinkler or surface irrigation methods under farmer management were measured and compared. The measurements were recorded from 2020 to 2021, on 17 farms across Esfahan Province where onion was a main crop in the region. The measured data from the foregoing two irrigation methods were statistically analyzed using t-test and Pearson correlation coefficients. The outcomes revealed that the volume of irrigated water as well as crop yield was greater for surface irrigation method compared to sprinkler irrigation, and the differences were statistically significant. Moreover, water productivity for onions irrigated with a sprinkler irrigation system was significantly higher (p<0.01) in comparison with onions irrigated with the surface method. In addition, the results indicated a significantly direct correlation between the volume of irrigated water and onion yield, whereas a significantly indirect correlation was observed between the volume of irrigated water and water productivity. A significantly inverse correlation was found between the productivity of energy for irrigation and energy consumption; so, an increase in the energy for irrigation resulted in a decrease in energy productivity. Based on the results of this study, the sprinkler method is more effective than the surface for irrigation of onion.
M. R. Taghizadeh, A. Motamedi, M. Galoie, F. Kilanehei,
Volume 27, Issue 4 (12-2023)
Abstract
Understanding flow behavior over bedforms is one of the most complex topics in sedimentary engineering. Despite numerous studies that have been conducted on river beds, the understanding of the interaction between flow and bed in turbid and clear waters is still impoverished. The present study mainly focused on simulating clear and turbid flows using SSIIM software. This study modeled the flow through a 12-meter channel with nine consecutive dunes of 1-meter length and 4 cm height. Nine simulations were performed to investigate the effects of flow velocity and flow separation zone in clear and turbid water. Finally, the results were compared with the experimental results of previous researchers using the PIV. The modeling results showed that the length of the flow separation zone increases with increasing velocity, and the highest probability of flow separation occurs at the highest velocity. In turbid flow, flow separation is less than the same flow condition in clear flow, and as fluid density increases, the length of the flow separation zone decreases. This study demonstrates the acceptable functionality of the SSIIM software and its accuracy in estimating flow behavior with and without sediment.
A. Barikloo, S. Rezapour, P. Alamdari, R. Taghizadeh Mehrjardi,
Volume 27, Issue 4 (12-2023)
Abstract
Soil quality is one of the most crucial factors determining crop productivity and production stability. The soil's physical, chemical, biological, and ecological characteristics affect its quality. Numerous researchers have concentrated the evaluation on a small number of soil quality indicators because measuring all soil quality indicators would be time-consuming and expensive. This study looked at the spatial autocorrelation of soil quality in the southwest areas of the Urmia Plain to establish the minimal data set for quantitative assessment. To accomplish this, 120 composite soil samples were collected from a depth of 0 to 60 cm, and the soil quality index was then calculated using the IQI method in 4 modes: Total-Linear (IQIwL-TDS), Total-Nonlinear (IQIwNL-TDS), Minimum-Linear (IQIwL-MDS), and Minimum nonlinearity (IQIwNL-MDS). 22 physical and chemical characteristics were used to choose the data set. The characteristics of sand percentage, sodium absorption ratio, cation exchange capacity, Available phosphorus, active calcium carbonate, and nickel concentration were chosen as the minimum data set (MDS) using the decomposition method into principal components. The linear IQIMDS mode produced the greatest soil quality index result, whereas the non-linear IQIMDS mode produced the lowest. The non-linear mode of the IQI index has a greater correlation coefficient (R2=0.85) than the linear mode of the IQI index (R2=0.73), according to an analysis of the linear and non-linear correlation coefficient between the soil quality index with the total category and minimum data. The findings of computing the global Moran's index for study sets of IQI soil quality index data revealed that the soil quality data are not independent of each other and are spatially autocorrelated, distributed in clusters, and have spatial autocorrelation. Getis-ord GI statistics indicated that the eastern and southeastern parts of the research region comprise clusters with poor soil quality, salt marshes produced by Lake Urmia's drying up, and surrounding arid plains.
B. Akbari, H. Khademi,
Volume 27, Issue 4 (12-2023)
Abstract
Street dust enters the urban environments due to the resuspension of particles smaller than 100 micrometers. The magnetic properties of street dust and their relationship with the concentration of heavy metals have received less attention from researchers worldwide, and not much study has been performed on this issue in Iran. The objectives of this study were: (i) to investigate the spatial and seasonal changes in street dust, and (ii) to determine their relationships with the concentration of selected heavy metals in several cities in the Isfahan province. Sampling was carried out in the first half of the second month of each season including 20 samples from Isfahan city and 10 samples from Natanz, Shahreza, Falavarjan, Khomeinishahr, and Najafabad. The concentration of selected heavy metals was measured using an atomic absorption spectrometer. Also, the magnetic susceptibility values of the samples at low and high frequencies were determined and frequency-dependent magnetic susceptibility was calculated. The results showed that the presence of ferromagnesian minerals in the parent materials could be the reason for the high values of magnetic receptivity in Natanz City. However, the high level of this characteristic in the street dust of other cities could be due to human activities, especially in Isfahan city. Based on the results of principal component analysis, the high correlation of the first component with magnetic susceptibility and the concentration of zinc, copper, and chromium elements most likely indicates the absorption of these elements by particles close to superparamagnetic (SP). The high correlation of the second component with frequency-dependent magnetic susceptibility and concentration of nickel and cobalt is most likely related to the adsorption of magnetic elements and heavy metals into coarse polyhedral particles that remained on the street floor after the re-deposition of street dust particles. Also, the high correlations between magnetic parameters and the concentration of copper and zinc confirm their anthropogenic origin. On the other hand, low or negative correlations of Pb, Ni, Cr, and Co concentrations with magnetic susceptibility might confirm their natural or non-anthropogenic origin. The higher values of magnetic parameters of street dust in the spring season reflect the significant contribution of magnetic minerals in this season, compared to autumn and winter, and indicate the higher influence of human activities.
M. Naderi, V. Sheikh, A. Bahrehmand, C.b. Komaki, A. Ghangermeh,
Volume 27, Issue 4 (12-2023)
Abstract
Greenhouse gases and the occurrence of climate change have occurred with the development of technology and the industrialization of human societies. long-term forecasting of climate parameters has always been interesting due to the importance of climate change for the earth and its inhabitants. General Circulation Models (GCMs) are one of the most widely used methods for evaluating future climate conditions. In the present study, the results of three general circulation models including the American model of GFDL-CM3, the Canadian model of CanESM2, and the Russian model of inmcm4ncml for the study area were evaluated and the CanESM2 model was selected as the superior model. The RCP scenarios 2.6, 4.5, and RCP 8.5 were used with the CanESM2 model to assess climate change conditions across the Hablehroud River basin for the period 2020-2051. According to the results, the total monthly precipitation shows an increasing trend in the coming decades 2020-2051 period compared to the period 1986-2017. The results of the study of temperature changes in the period 2020-2051 in the Hablehroud River basin also indicate an increase in the monthly average of maximum and minimum temperatures in the coming decades. The consequences of these conditions are of great hydrological importance in the study area, this condition necessitates the adoption of climate change adaptation policies in this watershed.
A.s. Hosseini Khezrabad, A.a. Vali, A.h. Halabian, M.h. Mokhtari,
Volume 27, Issue 4 (12-2023)
Abstract
Desertification is one of the most serious ecological environmental problems in the arid regions. Quantitative assessment of the desertification process is important for the prevention and control of desertification. In this research, the IMDPA model was used to evaluate the quantitative and qualitative desertification situation in the northwest of Yazd. Three criteria of soil, vegetation, and wind erosion were considered in this model. Several indicators were defined for each criterion with a weight of 0 (low) to 4 (very severe). The geometric mean of all three criteria was used to prepare a map of sensitive areas to desertification in ArcGIS. The results indicated that more than 92% of the research area was in the extreme class of desertification, and only the dunes work unit was in a very intense class. Finally, the whole of the research area with a final score of 3.04 was placed in the extreme class of desertification intensity. Also, the soil criterion with the highest weight score of 3.26 has had the greatest impact on the desertification of the northwest region of Yazd. Therefore, it is necessary to implement remedial and revitalization operations in this region according to the expansion of the phenomenon of desertification and the high influence of the soil criteria. The results of the research showed the intensity of desertification, the potential, and the sensitivity of the region to the phenomenon of desertification can be referred to as a departure from the natural functioning of the system.
S. Koohi, B. Bahmanabadi, Z. Partovi, F. Safari, M. Khajevand Sas, H. Ramezani Etedali, B. Ghiasi,
Volume 27, Issue 4 (12-2023)
Abstract
Water supply remains a significant challenge in arid and semi-arid regions, and in addressing this concern, unconventional water sources have gained prominence. Notably, the extraction of water from air humidity, classified as an unconventional water source has seen increased adoption. Diverse techniques have been developed to achieve this goal, with the utilization of mesh networks being particularly prevalent. Consequently, this study assesses the evaluation of the performance of the ERA5 dataset in the simulation of atmospheric variables that influence the ability to assess water harvesting from air humidity (including temperature, wind speed, and water vapor pressure). Also, the possibility of water harvesting from air humidity was investigated in Qazvin Province. The outcomes demonstrated the benefit of incorporating adjustment coefficients in estimating temperature and wind speed using the ERA5 dataset. Based on these findings, the northwestern and southern regions of the province (Kuhin and Takestan) exhibit notable potential during spring and summer for water harvesting from the atmosphere. The peak water harvesting for these stations in the summer is estimated at 10.2 and 9.7 l/day.m2, respectively. Using the ERA5 reanalysis dataset, the annual average potential for water harvesting in the stations was evaluated at 7.9 and 4.6 l/day.m2, respectively. Notably, the minimum water harvesting capacity during the summer season recorded in Qazvin is equal to 3.39 l/day.m2, which can be planned for use in irrigation requirements of green spaces, fields, or gardens.
M. Majedi Asl, T. Omidpour Alavian3, M. Kouhdaragh,
Volume 27, Issue 4 (12-2023)
Abstract
Weirs of the labyrinth have some advantages including the high coefficient of the irrigation of weir and the low fluctuation of water when the flow passes over the crest of the weir. In this research, the flow rate coefficient has been investigated by changing the weir geometry in terms of wall slope, arc cycle angle, and nose length change in the upstream and downstream of each cycle of the trapezoidal arc labyrinth weir. A total of 240 tests have been performed on 16 different physical models in a channel with a width of 120 cm and a narrowing of 20 cm from each wall. All models have been compared with the control model (normal labyrinth weir) (80A). The results showed that the 80B weir with an arc cycle angle of 20 degrees and without wall slope has a better performance than other weirs. Also, the weir with an arc cycle angle and a wall slope of 20 degrees in a divergent form (D20B) in the area (Ht/P) <0.31 has a better performance than other weirs with an arc cycle angle of 20 degrees, and after this area, the weir with a wall slope of 10 degrees has performed better in divergent form (D10B). In weirs with different cycles at an arc cycle angle of 20 degrees, the labyrinth weir with 5 cycles (N5) has performed better up to the point (Ht/P)=0.36. Also, at the maximum point, the difference is 13 and 17%, respectively, compared to the 4-cycle and 3-cycle weirs.
R. Sargholi, A. Bordbar, A. Asareh, M. Heidarnejad,
Volume 28, Issue 1 (5-2024)
Abstract
In the past, various methods have been proposed to control beach heel scouring. For shallow rivers (such as mountain rivers), various types of overflows are used. Therefore, the development of scour in cross-vane and w-weir structures for coastal protection was investigated in this study. The results showed that by installing a w-weir structure in a 90-degree position compared to a 30 and 60-degree position, a 37.9% and 19.7% reduction of scouring was observed, respectively. Also, by installing the cross vane structure in the 90-degree position compared to the 30 and 60-degree position, a 35.4% and 21.2% reduction of scouring was observed, respectively. With increasing width (L / B) (ratio of the width of structure to the width of flume), the w-weir structure decreased from 1.5 to 2, scour rate of 7.9%. Also, with increasing width (L / B) (ratio of the width of structure to the width of flume), the cross-vane structure has decreased from 1.3 to 1.7, and the scour rate has decreased by 4.7%. The w-weir structure had an average of 7.3% less scouring than the cross-vane structure.
M. Baki, J. Abedi Koupai,
Volume 28, Issue 1 (5-2024)
Abstract
The improvement of water consumption efficiency is very significant, especially in arid and semi-arid regions. In this research, the effects of three hydrogel rates (0, 10, and 50 Mg ha-1) and three irrigation regimes (50%, 70%, and 100% of water requirement) on growth, yield, and oil production of Thymus daenensis were studied in a lysimetric experiment. The process of hydrogel synthesis was performed with sodium alginate as the main bone of the polymer and acrylic acid and acrylamide as monomers with the rapeseed meal biochar was made at 300 ºC. The results showed that the essential oil content produced by the plant was impressed by the hydrogel application. The essential oil content increased with an increase in water deficit, but the essential oil yield decreased in the lysimeters with water deficit compared to the ones without water stress. Besides, the application of 50 Mg ha-1 hydrogel caused a 17% increase in the dry matter and a 12% increase in the plant's height. According to the results of this experiment, the application of hydrogel caused the improvement in most characteristics of the Thymus daenensis in water stress conditions.
Z. Naderizadeh, H. Khademi, A. Shamsollah,
Volume 28, Issue 1 (5-2024)
Abstract
Although several reports are available on the distribution of Palygorskite in the soils of arid regions of Iran, there is not much information about the presence and abundance of this important fibrous clay mineral in the soils of Bushehr Province. This research was carried out: (1) to investigate the distribution of Palygorskite and other major associated clay minerals, and (2) to evaluate the relationship between the relative quantity of Palygorskite in clay-sized fraction and the most important soil properties in Dashtestan County, Bushehr Province. Five geomorphic surfaces including eroded rock outcrop, rock outcrop, dissected hill, alluvial fan, and alluvial plain were identified in the study area using Google Earth images and field observations. After sampling representative pedons, the clay mineralogy of two horizons from each pedon was determined. X-ray diffractograms and SEM images showed that in the studied soils, which were classified as either Aridisols or Entisols, Palygorskite was present in different quantities on all geomorphic surfaces. Moreover, Illite, Chlorite, Smectite, irregularly interstratified Chlorite/Illite, and Kaolinite were the other clay minerals that existed in the soils studied. The relative quantity of Palygorskite and Smectite was variable on different geomorphic surfaces. Regardless of the type of geomorphic surface, petrogypsic and gypsic horizons showed the highest quantity of Palygorskite as compared to other horizons which seems to be due to the suitable geochemical conditions of these horizons for the formation and stability of Palygorskite mineral. The higher correlation of Palygorskite content with gypsum, as compared to that with the carbonates, indicates the importance of gypsum in Palygorskite distribution in the soils of the study area. The findings also indicated that the amount of Palygorskite was positively correlated with soluble Mg/Ca ratio, pH, gypsum, and soluble Mg. These parameters appear to control the genesis and distribution of Palygorskite in the soils studied. In general, it is necessary to pay special attention to their clay mineralogy, especially the significant amount of Palygorskite to manage the soils of the study area and to reasonably predict their behavior.
S. Ghasemi Pirbaloti, S. Soodaee Moshaee,
Volume 28, Issue 1 (5-2024)
Abstract
Since the long-term sustainability of garden ecosystems is dependent on maintaining the soil quality, knowing the condition of the soils and investigating the effects of the activities on the soil properties is very important and effective in ecosystem management. To investigate the soil quality index of almond (Prunus dulcis) orchards under different managed methods in ChaharMahal va Bakhtiari province, soil samples were collected from three points in each orchard and finally classified into 6 groups (Saman, Ben, Shahrekord, Kiar, Ardel, and Farsan). To determine the soil quality index, soil characteristics including pH, EC, total and water-soluble organic carbon, basal and substrate-derived respiration, rhizosphere microbial population, and available soil P and K were analyzed. The results showed that almond orchard management in different regions affected the soil characteristics and the processes evaluated in this study. The monitoring of soil properties showed that pH 7.05 - 8.48, EC 0.23 - 2.91 dS/m, microbial respiration 0.44 - 8.57 mg CO2.100 g-1.day-1, organic carbon 2.09 - 44.79 g/kg, available phosphorus 1.5 - 122.3 mg/kg, and available potassium were between 91.2 - 3038 mg/kg. Soil quality index components including chemical components, microbial activity, microbial population, and soil organic carbon were determined. The contribution of soil salinity to soil quality obtained using factorial analysis was the highest (31%), followed by microbial carbon mineralization coefficient (27%), rhizosphere microbial population (24%), and water-soluble organic carbon (18%). The soil quality index values for Saman, Ben, Shahrekord, Kiar, Ardal, and Farsan almond orchards were 0.46, 0.40, 0.51, 0.67, 0.54, and 0.37, respectively. These values showed that the evaluated soils are suitable for almond production in Shahrekord, Kiar, and Ardal, and for Saman, Ben, and Farsan, there is a need for serious management measures to improve soil quality and increase the sustainability of these agricultural ecosystems.
F. Gholamzadeh, H. Asgarzadeh, H. Khodaverdiloo, M.r. Mosaddeghi,
Volume 28, Issue 1 (5-2024)
Abstract
This study was conducted in the summer of 2021 to evaluate and validate the gravimetric soil water content measurements using a field oven. Ten soil types with a salinity of saturated paste (ECe) less than 4 dS m-1 and three saline soils were studied around Urmia Lake. Plots with dimensions of 1 m × 2 m were prepared for the selected soils to measure gravimetric soil water content and soil physical and chemical properties. The gravimetric water content (θm) values measured using the field oven (i.e., θmFO), were compared with those measured by a standard lab oven (i.e., θmLO). The soil water content values measured in the lab, regarded as a benchmark, were measured at 105 °C for 24 h. Temperatures of 120, 140, and 160 °C with three durations of 10, 15, and 20 min were used to dry the soil samples in the field oven. There was very good compatibility between the values of θmFO and θmLO when the soil samples were dried in the field oven for 15 or 20 min at all three temperatures. Significant linear relations were obtained between the θmFO and θmLO values as the slopes of linear relations were close to 1, the intercepts of relations were negligible and the distributions of measured data around the line 1 to 1 were unbiased. The minimal effects of soil organic matter content, clay content, salinity, and bulk density on water content measurements by the field oven indicate an important advantage of this method. These results confirm the high efficiency of the field oven for fast and reliable measurements of water content in different soils.
A. Zare Garizi, K. Shahedi, A. Matboo,
Volume 28, Issue 1 (5-2024)
Abstract
Water quality characteristics play a crucial role in water resources management, watershed health assessment, and implementing effective management strategies. The objective of this research was to present an overall assessment of the surface water quality in the Gorganrood River Basin to be utilized for developing effective watershed management plans and programs. Various physicochemical water quality data including main anions and cations, Total Dissolved Solids (TDS), Electrical Conductivity (EC), Sodium Absorption Ratio (SAR), pH, and total hardness recorded at 25 hydrometric stations across the basin were analyzed and assessed with the Canadian (CCME) Water Quality Index. The mean water quality index for drinking, agriculture, and industrial purposes indicated that headwaters and higher areas generally exhibited better water quality compared to the downstream areas of the basin. Geochemical processes and the introduction of various pollutants during water flow from the headwaters to the basin outlet contribute to a decline in water quality. The highest water quality was observed in the Kabudval and Shirabad stations, whereas the Baghesalian station exhibited the lowest. For drinking water use, hardness, bicarbonate, and chloride were identified as variables contributing to water quality decline in the headwaters and upstream areas. However, these areas predominantly maintained a moderate to good quality for drinking purposes. Conversely, downstream areas experienced a significant deterioration in water quality with higher pollutant levels such as total dissolved solids (TDS), sulfate, and sodium, resulting in relatively poor to poor conditions. Approximately 60% of the stations in the basin had excellent water quality for agricultural use, with no limiting factors. Only three stations near the basin's outlet exhibited relatively poor to poor water quality due to elevated chloride levels, sodium adsorption ratio (SAR), and electrical conductivity. only 28% of hydrometric stations demonstrated good water quality for industrial use. Hardness, pH, and TDS are the main variables contributing to water quality decline for industrial use in the upstream, while downstream areas are impacted by chloride and sulfate. The outcomes of this study hold significant implications for effective water resources management, watershed preservation, and natural resource conservation in the Gorganrood basin. From industry and especially health aspects, however, more detailed investigations are needed, taking into account some other important variables of water quality (including nitrate, total coliform, fecal coliform, etc.).
S. Abdollahi, A. Masjedi, M. Haidarnejad, A. Afros, M. Asadilor,
Volume 28, Issue 1 (5-2024)
Abstract
The use of structures has economic and safety advantages compared to other energy-consuming structures. In this research, to investigate the effect of the length of the sill of the flip bucket spillway on the scour downstream, experiments were conducted in a rectangular laboratory flume made of Plexiglas. The scouring downstream of the flip bucket spillway was investigated using a flip bucket spillway with four relative sill lengths and four threshold angles at four current intensities in the channel in this research. The results of this research showed that by the increase in the length of the sill in the flip bucket spillway, the energy consumption in the spillway increased and the scour depth downstream decreased. Also, increasing the relative length of the sill by 70% at the sill angle of 45 degrees, the scouring depth is reduced by about 88%. Also, a relationship was presented to determine the maximum depth of relative scour, and the correlation coefficient of the results obtained from this equation with the laboratory results is about 0.92.
M. Karamdokht Bahbahani, M. Sajjadi, J. Ahadiyan, A. Parsaie,
Volume 28, Issue 1 (5-2024)
Abstract
One of the structures for regulating the water level in the irrigation and drainage ducts is the lopac gates, which are proposed as a structure for regulating and controlling the flow level. In this study, a new design of this type of structure has been proposed in which the gates are placed next to each other in pairs, and they are called multiple lopac gates. The objective of this research is to investigate the effective hydraulic parameters of the proposed structure and compare it in a case where a gate is used under the same conditions. All the simulations were modeled with 3 amounts of opening 30, 45, and 60 degrees and at 3 flow rates of 20, 40, and 60 liters per second and using Flow3d software, in these simulations, the number of mesh cells is 1000000 and RNG turbulence model is used. The results showed that the maximum shear stress was reduced by an average of 38% compared to the single gate mode in most tests at different openings and flow rates using multiple lopac gates, and the largest amount of this reduction was related to the opening of 45 degrees, and the flow rate is 40 liters per second with a value of 76%. Also, the forces acting on the gate at different flow rates and openings will be reduced by 150% on average. In the qualitative investigation of flow vortices, the investigations also showed that vortex range, length, and strength are reduced compared to the single gate mode when two gates are used, and the number of vortices increases compared to when a single valve.
E. Karamian, M. Navabian, M.h. Biglouei, M. Rabiei,
Volume 28, Issue 1 (5-2024)
Abstract
Cultivation of rapeseed as the second crop requires drainage systems in most of the paddy fields of the Guilan province. Mole drainage, as a low-cost and shallow drainage method that is suitable for rice cultivation conditions and easier to implement than pipe drainage, can be a solution in the development of second-crop cultivation. The present study was conducted to evaluate the drainage of mole drainage and nitrogen fertilizer management on the quantity and quality of drainage at Guilan University. In this regard, an experiment was conducted under two treatments including drainage and nitrogen fertilizer (i.e. traditional mole drainage and sand-filled mole drainage), and 180 and 240 kg of nitrogen fertilizer per hectare in three replications. After each rainfall during the plant growth period, water samples were taken from the drains, and parameters of electrical conductivity, pH, total suspended solids, total phosphorus, turbidity, concentrations of ammonium, chloride, nitrite, nitrate, and phosphate were measured. Also, the outflow from the drains and the water table level were measured by piezometers during the rain and after that. The results of the mean comparison of pH and total suspended solids showed that most of them were obtained with 7.49 and 281.25 mg/liter, respectively, in the mole drain filled with sand and the traditional mole drainage and 180 fertilizer treatment. The highest mean of electrical conductivity and turbidity was observed as 651 micro mohs/cm in the traditional mole drainage and 240 fertilizer treatment and with 67.76 NTU in the traditional mole drainage and 180 fertilizer treatment. The statistical analysis showed that the effect of drainage treatment on the amounts of ammonium, nitrite, nitrate, phosphate, and total phosphorus was not significant. The outflow from the traditional mole drainage was 49% lower than the sand-filled mole drainage. The traditional and sand-filled mole drains were able to drain excess water with average reaction coefficients of 0.8 and 0.83 per day during the growth period, respectively. Considering the speed of water discharge, drain discharge, and the main non-significance of qualitative parameters among drainage treatments, mole drainage filled with sand is recommended for the development of rapeseed cultivation in paddy fields.
M. Saeidi Nia, H. Mousavi, S. Rahimi Moghadam,
Volume 28, Issue 1 (5-2024)
Abstract
Due to the lack of water resources and excessive evaporation in the country, it is necessary to have a detailed irrigation program and a suitable management method. The present research was conducted to investigate the effect of superabsorbent and mulch in Khorramabad in July 2022 in a factorial combination with a completely randomized design in three replications. The first experimental factor was irrigation water treatment in 4 levels including irrigation that provided 100% water requirement (I100), 80% of crop water requirement (I80), 60% of crop water requirement (I60), and 40% of crop water requirement (I40). The second factor included different corrective materials including plant mulch (M), superabsorbent (S), and control treatment (I). The results showed the maximum amount of wet and dry yield and crop height was related to I100-M treatment, i.e. 100 percent water requirement and compost corrective material, which were 89.52 tons per hectare, 29.42 tons per hectare, and 2.27 meters. The maximum wet and biological productivity for I40-S was calculated as 14.24 kg of wet matter per cubic meter of water and 4.75 kg of dry matter per cubic meter of water. The lowest wet and dry yields were related to I40-M, which decreased the yield of the control treatment by 6.5 percent and 0.9 percent. The lowest productivity was related to the I100-S treatment, which was calculated as 3.13 kilograms per cubic meter of water for biological productivity and 9.14 kilograms per cubic meter of water for wet weight productivity. In general, mulch had a better performance in the treatments where the water stress was low, but when the water stress increased, the performance of the mulch treatments decreased. In the superabsorbent matter, the treatments with complete irrigation or with less stress, yield decreased, but the treatments with increased stress showed better results than most of the corrective materials and the control treatment.
M. Kashi, S. Alizadeh Ajirlo, N. Najafi,
Volume 28, Issue 1 (5-2024)
Abstract
The reduction of water resources due to the issue of global climate change and population growth is one of the most critical issues facing the designers and planners of the development of green spaces in cities. Against these challenges, there is an urgent need to improve the efficiency of water consumption and chain use of water resources with suitable options. Due to the significant volume of urban wastewater Effluent, its reuse in green space irrigation is important from the point of view of water resource management from an ecological and economic point of view. The effect of the Parand city wastewater treatment plant on the chemical properties of soil under the cultivation of three types of cover crops (Frankinia (FR), Festuca (FE), Dichondra (DI)) in a bed with sandy loam soil is investigated. This study was conducted as a factorial experiment based on a completely randomized design using mixing of water and Effluent at 4 levels with irrigation treatments of zero (control), 50, 75, and 100% compared to fresh water and 3 replications, and then the soil chemistry characteristics such as pH, EC, OC, Na, Cl, Ca, and Mg were evaluated. The results obtained from the soil chemical analysis parameters showed that the pH value decreased in all the treatments with effluent compared to the control, and this decrease was not significant in any treatment. The values of EC and Cl have increased in all plants, and these values were significant in the FR100 treatments with an increase of about 195 and 561% compared to the control, and in the FE100 treatment with an increase of about 54 and 162%, respectively, at the 5% probability level. The amount of OC in the FR100 treatment was significant with an increase of about 41% compared to the control treatment, but in other plants, this ratio was not significant in any treatment. The maximum amount of Mg in the FR50 treatment was 30.27, which has a significant effect compared to other treatments. The amount of Na and Ca in the FR100 treatment was significant with an increase of about 343% and 130%, respectively, compared to the control treatment, while in FE and DI plants, this ratio was not significant in any treatment.
I. Kazemi Roshkhari, A. Asadi Vaighan, M. Azari,
Volume 28, Issue 1 (5-2024)
Abstract
Due to climate change and human activities, the quality and quantity of water have become the most important concern of most of the countries in the world. In addition, changes in land use and climate are known as two important and influential factors in discharge. In this research, four climate change models including
HADGEM2-ES, GISS-E-R, CSIRO-M-K-3-6-0, and CNRM-CM5.0 under two extreme scenarios RCP2.6 and RCP8.5 were used as climate change scenarios in the future period of 2020-2050. The future land use scenario (2050) was prepared using the CA-Markov algorithm in IDRISI software using land use maps in 1983 and 2020. The SWAT model was calibrated to better simulate hydrological processes from 1984 to 2012 and validated from 2013 to 2019 and was used to evaluate the separate and combined effects of climate change and land use on discharge. The prediction of the climate change impact on discharge showed a decrease in most of the models under the two scenarios RCP2.6 and RCP8.5. The average maximum decrease and increase under the RCP2.6 scenario is 60 and 30 percent, respectively. This significant reduction is greater than that predicted under the RCP8.5 scenario. Examining the combined effects of climate and land use change revealed that the average decrease in discharge in the months of October, November, December, and January under two scenarios is 46.2 and 58%, respectively. The average increase in discharge is predicted to be 47% under the RCP8.5 in the months of April and May in the HadGEM2ES.
