Showing 8 results for Salar
B Salari, M Shamsedin Said, A Askarian Sardari,
Volume 12, Issue 46 (fall 2009)
Abstract
In order to study the effect of NaCl priming on some agronomical and physiological traits of corn (single cross 704), an experiment was conducted at Agricultural Research Station of Bahonar University of Kerman in 2005. The experimental design was completely randomized designs with 3 replications. Treatments were a combination of all different levels of two factors including salinity levels (1, 4, 8, 12, 16 dS/m) and salinity solution for NaCl priming (1, 4, 8, 12, 16 dS/m). Results showed that salinity and NaCl priming had significant effects on total emergence, mean time to emergence, root and stem length, number of leaf, relative water content, ion leakage and K+/Na+. Mean comparison showed that increasing salinity decreased all plant characteristics (with the exception of mean time to emergence and ion leakage) by %49.5, %33.49, %23.97, %18.64, %14.05 and %40.20, respectively. However, increasing salinity led to 1.2 and 1.3 increase in mean time to emergence and ion leakage of leaves, respectively. Mean comparison also showed that NaCl priming decreased negative effects of salt stress, and all mentioned traits under NaCl priming increased as compared with control. The results showed that NaCl priming is a useful method for increasing salt tolerance in corn plant.
M. Dorosti, M. Shafai Bajestan, F. Amirsalari Maymani,
Volume 22, Issue 2 (Summer 2018)
Abstract
Scour around structures in the river is the most destructivr factor of these structures. Therefore, different methods have been studied to reduce it. A creation slot is one of these methods in the suitable position that can be modified to control the flow pattern scour. In this study, the effects of using two parallel chord rectangular slots in the single spur dike with the opening of the effective spur dike area of 10% and a ratio of a/b = 4 (a and b are the length and width of the slot) on two occasions were investigated, one near the bed (near the slot spur dike) and the other near the water surface (away from the nose of spur dike) on the pattern of erosion and sediment around the nose triangular spur dike in clear water conditions. In all experiments, flow depth and angle of the triangular spur dike installation angle were constant. The experiment was done in different hydraulic conditions (Froude number 0.287, 0.304, 0.322). Eventually the results of spur dike without slot (control experiments) were compared. The results showed the slot near the bed toward the slot near water surface and control experiments had a better performance in reducing the maximum depth of scour and deposition of sediments washed to the outer bank. The reduction of the maximum depth of scour at the slot near the bed in Froude numbers 0.287, 0.302 and 0.322, respectively, was compared to the control experiments , which were 23%, 13% and 24%, respectively, and then compared to the slot near the water surface, which was 60%, 40% and 32% respectively.
K. Esmaili, S. Seifi, H. Salari,
Volume 22, Issue 3 (Fall 2018)
Abstract
Settling basins are one of the most essential structures for the separation of inflow sediments. This structure is established to enhance the water quality after the river-basins and water channels. Numerous studies have been conducted on the design of this structure and different methods have been provided to increase its efficiency. However, the use of simple settling basins with the minimum cost which can provide the ideal targets has been the focus of designers. In this study, the effect of flow-guiding plates and the angle between these and the inflow, and the impact of water depth in the basin on the trap efficiency of the settling basins were considered. For testing, 4 blades with specific length and angle were installed. This experiment was repeated for 3 different lengths and 3 angles. The results of the experiments showed that with the enhancement of the depth of water to 10 centimeters to 30 centimeters, while the basin had no flow-guiding plates, increased the trap efficiency of the basin by 4.9 percent. Also, by the use of flow-guiding plates in the suitable and best length and angle (in this study, the suitable size of blades was 22.5 centimeters and the best position was by the angle of 30 degrees); with the maximum of the water depth of 30 centimeters, the trap efficiency was increased by 13.3 percent. The sensitivity analysis done showed that the depth of water had the most effect on the trap efficiency of the basin and the changes in the lengths and angles of the blades position had the similar effects of the basin trap efficiency.
M. Mirjani, M. Soleimani, V. Salari,
Volume 24, Issue 1 (Spring 2020)
Abstract
Growing concerns about water pollution and its potentially harmful effects on human being have stimulated serious efforts to develop reliable biological monitoring techniques. The bioluminescent analysis is one of the most promising approaches for the biomonitoring of the environment, due to the sensitivity of the luminescent system to even micro quantities of the pollutants. The aim of the current study was to assess the petroleum compounds toxicity using Vibrio fischeri bacterium. The growth pattern of the bacterium was determined in photobacterium broth using the optical density measurement at 600 nm, which showed the optimum growth time of 16-18 hours after inoculation. In this research, the effects of environmental parameters such as temperature, pH and various concentrations of oil on the growth and luminescence of Vibrio fischeri were examined. The results revealed that the optimum growth conditions of the bacterium after 16 hours included the temperature of 25 °C and pH 7. Besides, the growth and luminescence intensity of Vibrio fischeri were a function of total petroleum hydrocarbon concentrations in the medium, which were significantly reduced in oil concentrations by more than 4% w/v. Therefore, the Vibrio fischeri could, therefore, have the potential for monitoring of petroleum pollutants in the aqueous media.
H. Siasar, A. Salari,
Volume 27, Issue 1 (Spring 2023)
Abstract
Access to large precipitation data with appropriate accuracy can play an effective role in irrigation planning and water resources management. Satellite images generate high, wide, cheap, and up-to-date data is a good way to estimate precipitation. In this research, the Google Earth engine system and precipitation products from satellite images of PERSIANN and CHIRPS models in daily, monthly, and annual time intervals were used to evaluate and validate the amount of precipitation in Bandar Abbas station during the statistical period of 1983-2020. The results showed that the precipitation estimation by PERSIANN and CHIRPS satellites on a monthly and annual scale is more accurate than the daily scale. The highest correlation coefficient and the least RMSE belonged to the PERSIANN algorithm on monthly and annual scales. The value of the correlation coefficient in the PERSIANN algorithm on daily, monthly, and annual scales is equal to 0.32, 0.83, and 0.94, respectively. The correlation coefficient in the CHIRPS algorithm in daily, monthly, and annual scales is equal to 0.24, 0.71, and 0.90, respectively. The coefficient of determination (R2) of PERSIANN and Chrips algorithms on a monthly scale were 0.89 and 0.70, respectively, and for an annual scale were 0.88 and 0.80, respectively. The general conclusion of this study indicated that the accuracy of the two algorithms in determining the spatial pattern of rainfall on a monthly and annual scale is appropriate, and the PERSIANN algorithm had a higher accuracy on a monthly time scale.
T. Mohammadi, V. Sheikh, A. Zare, M. Salarijazi,
Volume 27, Issue 3 (Fall 2023)
Abstract
A quantitative study of groundwater resources and accurate monitoring of changes over time, especially in areas facing limited water resources, is considered essential for proper management and sustainable exploitation of these resources. Golestan province, one of the semi-arid provinces of Iran has faced a drop in the groundwater level and an increase in the salinity of the groundwater due to the excessive withdrawals from the groundwater table and the reduction of atmospheric precipitation in the past few years. Gorgan Plain with an area of about 4727 square kilometers is one of the largest plains in Iran and the most important plain of Golestan province in terms of water supply for agricultural and drinking purposes. In this plain, there is a network of piezometers and observation wells that include continuous monthly measurements for more than 30 years. The objective of this research was to investigate the changes in the groundwater level of shallow (30 years (1989-2018)) and deep (22 years (1997-2018)) wells. The Man-Kendall method was used to reveal the trend and Pettitt, Normal Standard, and Buishand methods were used to identify sudden change points in a time series of groundwater levels in 49 shallow wells and 12 deep wells. The results of this research showed that the groundwater level in most of the studied wells had a significantly decreasing trend at a significant level of 5%. Also, the largest amount of groundwater loss was in the southern and southwestern parts of the plain, which can be attributed to a large amount of water taken from the wells due to their proximity to urban areas and some local conditions such as the proximity of the wells of this area are located in altitudes and at the entrance border of the aquifer. In the same way, as it rises, the fall decreases in the middle of the plain, and the amount of fall decreases in the northern areas and the edge of the Caspian Sea. It can be related to the proximity to the Caspian Sea and the high water table, and as a result, the inappropriate quality of water and land (high salinity and low fertility), which has caused the water withdrawal from this area to be less.
M. Salari, V. Rahdari, S. Maleki, R. Karami,
Volume 27, Issue 4 (Winter 2023)
Abstract
the countries of Iran and Afghanistan. A long period of drought has happened in this area by human interventions after 1999. The objective of current study is to predict the Hamoun wetland situation in scenarios with and without human intervention using the Markov model-automated cellular for 2019 and the next forty years. Land cover maps of the study area using satellite images for 1987 as a normal year, 1991 as a wet year, and 2019 as a year with human effects were prepared. Then, prediction model for 2019 were prepared using 1987 and 1991 cover layers in four scenarios, prediction models were prepared for the next forty years in normal, drought, and wet conditions. If the natural process of watering of Hamoun wetland continues, lower than 362735 hectares of wetland should become watering in 2019, while, according this year land cover map, less than 50000 hectares of wetland have water. Also, by continuation of the current trend and the effect of human activities in the 40-year models, 11230 hectares of the area will be watering, and if the natural process of the wetland continued using the model of 2019 this amount was equal to 373311 hectares. The results of the research show the completely different situation of the Hamoun wetland in the case of no human intervention in the watering of this wetland in 2019 and the model of the next forty years.
A. Salar, M. Shahriari, V. Rahdari, S. Maleki,
Volume 28, Issue 2 (Summer 2024)
Abstract
Unbalanced development of different land use/cover in basins without considering the contribution of all components, can cause serious damage to the stability of the entire basin. The development of agricultural areas by increasing the amount of water use and creating dams upstream of rivers are the most important threats to wetlands in many places. Jazmorian wetland is one of the seasonal wetlands in the south-east of Iran. The most important source of water supply for this wetland is the Halil-Rood River. To investigate the land use/cover changes of Jazmurian wetland and
Halil-Rood River, the time series of Landsat satellite data for the years 1354, 1374, 1387, and 1401 were used in the present research. The Landsat satellite images were classified using a hybrid classification method and the land use/cover of the study area maps were prepared. The accuracy of the prepared maps for the latest image was calculated by preparing the error matrix, calculating the kappa index, and the overall accuracy of more than 0.8 and 9%, respectively. The investigation of the prepared maps showed that the area of land under water increased from 1354 to 1374 and then decreased from 119,552 hectares in 1374 to 723 hectares in 1401. The area of agricultural land increased from 2131 hectares in 1354 to 133913 hectares in 1387 and declined to 105795 hectares in 1401. The results of this study show that in this period, with the construction of a dam upstream of the Halil-Rood River, and the development of agricultural lands, the water volume level of the wetland decreased, and the wetland completely dried up in 1401. The present study indicates the necessity of considering different components of a watershed in development planning to achieve sustainable development.
