Showing 58 results for Heidar
Hadis Feizi, Mostafa Chorom, Arsalan Heidari,
Volume 17, Issue 64 (summer 2013)
Abstract
In order to describe soils polluted with hydrocarbons, the amount and distribution pattern of soil heavy metals (Ni, Cd) in soils were studied. Soil samples were taken from one of the western oil field of Iran. The field was naturally exposed to crude oil spillage into soil and consequently was environmentally polluted during the development, production, transportation and storage of crude oil. Sampling was started near the oil wells with maximum relative contamination and continued to the remote places based on grid sampling pattern. Samples were characterized by physicochemical analysis. The results revealed different levels of total hydrocarbons (from 0.12 to 2.99 mg/kg of dry soil), Ni (from 32 to 136 mg/kg. of dry soil) and Cd (from 0 to 4mg/kg of dry soil). In addition, the role of soil agents such as pH and EC and sedimentary indexes was considerable in controlling the pollution trend in the studied area. Finally, by interpolation module and prediction of unknown values via Kriging techniques, the expansion plans were created. The extracted plans obviously illustrated the decrease in the levels of pollution indexes with the increase in distance from the given centers of pollution
Mohammad Hossein Noori Gheidari,
Volume 17, Issue 64 (summer 2013)
Abstract
In order to monitor the changing water table in the field, determination of the main sampling points is very important to reduce sites and save time and cost. Principal Component Analysis (PCA) is one of the data reduction techniques used to extract the important components that explain the variance of a system. In this paper, the PCA was used to identify the effective wells of Qheidar Aqufer, Zanjan, to determine the groundwater level and remove the less important ones. From the study region which an area of about 920 km2, 48 wells (sites) were investigated. Using PCA, the relative importance of each well was calculated between 0 (for completely ineffective well) to 1 (for the very effective wells). The study showed the elimination of wells whose relative importance was less than 0.5 (i.e. half the total number of wells), coefficient of variation of groundwater level relative to the use of all wells did not greatly increase, and the error to determine the level of groundwater was less than 13 percent.
Bita Moravejalahkami, Behrouz Mostafazadeh-Fard, Manouchehr Heidarpour, Saeed Eslamian, Jaber Roohi,
Volume 17, Issue 64 (summer 2013)
Abstract
Most furrow irrigation systems have low performance due to deep percolation at the upstream end and tailwater runoff at the downstream end of the field. To eliminate this problem improving furrow irrigation performance is necessary. Since the inflow discharge has high effect on infiltration along the furrow which consequently affects the application efficiency and water distribution uniformity, it would be important to apply different furrow inflow hydrograph shapes based on the field data such as field slope, soil texture and furrow length to save water. To produce different furrow inflow hydrograph shapes, an automatic valve which was connected to a stepper motor was designed to change the inflow discharge with time according to the desired inflow hydrograph shape. The experimental field was located at Isfahan University of Technology. A constant head water delivery system to the furrows including the automatic valve was installed in the experimental field and the tests were conducted for different inflow hydrograph shapes. The comparison of the measured furrow inflow discharges with the simulated furrow inflow discharges produced by the automatic valve showed that the automatic valve can produce different furrow inflow hydrograph shapes with high accuracy.
S. M. J. Mirzaei, , S. H. Tabatabaei, M. Heidarpour, P. Najafi,
Volume 17, Issue 66 (winter 2014)
Abstract
There chemical and organic matter content in garbage leachate that may affect soil physical and hydraulic properties. The main objective of this study was to evaluate the influences of the leachate of Isfahan Organic Fertilizer Factory (IOFF) on some soil physical and hydraulic properties in a soil chemically enriched by Zeolite. The treatments include two soil textures (clay loam and sandy loam) and three levels of zeolite (0, 5 and 10 percent). The treatments were applied on lysimeters scale. The results showed that irrigation with the leachate caused a reduction of infiltration and hydraulic conductivity in the clay loam soil. The hydraulic conductivities in clay loam soil without zeolite (B0) before and after irrigation with leachate were 1.73 and 0.36 m/day, respectively. In contrast, there were no changes in the sandy loam soil’s infiltration and hydraulic conductivity. The hydraulic conductivities in the sandy loam soil with 5 percent zeolite (A5) before and after irrigation with leachate were 3.17 m/day. Furthermore, zeolite had a decreasing effect on those processes. The results show that irrigation with leachate caused reduction of bulk density in two types of soil and all levels of zeolite.
A. Heidari, A. Hemmat, S.m Rezvani,
Volume 18, Issue 67 (Spring 2014)
Abstract
efficiency was investigated during a 2-year period (2009-2010) in a silty clay loam soil in Tajarak Research Station
(Kaboudarahang Township), Hamedan. The experimental design was a strip-plot within a randomized complete blocks
design. The horizontal band, the irrigation water rate after flowering, included full and deficit irrigation (100% and 75%
potato water requirement) and the vertical band, kind of inter-planting row tillage including 1- subsoiling to 30-35 cm
soil depth, 2- chiseling to 20-25 cm soil depth, 3- sweeping to 5 cm soil depth and 4- no-till. During the growing
season, soil mechanical resistance (cone index) in two stages and water infiltration into the soil were measured. At the
end of the growth season (harvesting time), potato yield quantity and quality were measured. Result showed that the
effect of inter-row tillage on soil mechanical resistance was significant. Subsoiling and chiseling had lower soil
mechanical resistance and higher water permeability between treatments, respectively. The effect of inter-row tillage on
potato yield was significant so subsoiling and chiseling had a higher potato yield between treatments, respectively. The
effect of irrigation water rate on potato yield was not significant. The effect of inter-row tillage on water use efficiency
wasn’t significant.
M. Heidarpoor, S. H. Razavian, Y. Hosseini,
Volume 18, Issue 68 (summer 2014)
Abstract
The combined system of gate and weir is used for flow measurement in open channels. But in case the passing water has floating material and sediment it damages their performance and hence error of measurement will increase. In order to solve this problem, weir and gate can be combined and a concentrated hydraulic system known as weir-gate can be developed, thus allowing sediments transportation from under the gate and floating particles on weir. The principal goal of this study was to investigate the passing flow characteristics by trapezoidal weir and sharp-edge rectangular sluice gate in rectangular channel, and also suggest a discharge coefficient for combinational flow in different flow conditions. The experiments were carried out in laboratory channel on models with different geometric dimensions under various hydraulic conditions. Discharge coefficient was presented for various condition of passing flow of trapezoidal sharp-edge weir and below rectangular sluice gate using statistical analysis conducted on dimensionless geometric parameters affecting the flow. Resulting discharge coefficients were in agreement with laboratory results.
R. Rostamian, M. Heidarpour, S.f. Mousavi, M. Afyuni,
Volume 19, Issue 71 (spring 2015)
Abstract
In recent years, use of carbon-based adsorbents has increased in pollution reduction from aqueous solutions. Biochar is a carbon-rich porous material, with low costs, and environmentally friendly, which is prepared by pyrolysis of biomass. In this study, potential of rice husk biochar to desalinate irrigation water with EC of 5, 15 and 25 dS/m was investigated. The effect of pyrolysis temperatures of 400 (RHB4), 600 (RHB6) and 800 (RHB8) on selected physicochemical characteristics and their desalination power was considered. The results showed that pyrolysis temperature has a significant effect on biochar properties. RHB6 with 301.1 mg g-1 desalination capacity was more efficient than the other biochars. This adsorbent had maximum surface area (211 m2 g-1) and total pore volume (0.114 cm3 g-1). The results of this study could open new horizons to manage the agricultural wastes and simultaneously reduce the cost of irrigation water.
S. Samiee, M. Heidarpour, S. Okhravi,
Volume 19, Issue 73 (fall 2015)
Abstract
Side weir is the structure to evacuate extra water from a canal when level of water rises. This structure is mounted on the wall of canal. It is used predominantly to set flow in irrigation and drainage systems or urban wastewater harvesting systems. Implementing guide vanes is a simple way to increase side weir efficiency. In this study, the effect of using guide vanes on discharge and discharge coefficient of rectangular sharp-crested side weirs was investigated. ADV instrument was applied for recording vertical velocity over the crest of side weir. Local discharge was calculated by vertical velocity data for both conditions of presence and no presence of guide vanes. Results showed that in both cases, increasing the Froude number results in the decrease of passing discharge and discharge coefficient of the rectangular sharp-crested side weir. Data analysis also showed that by increasing the Froude number, guide vanes have more effect on increasing discharge coefficient and local discharge. The local discharge increased along the crest and the most passing local discharge occurred near the end of the side weir. Analysis indicates that using guide vanes leads to the increase of discharge coefficient by about 32%.
M. Goodarzi, J. Abedi Koupai, M. Heidarpour, H. R. Safavi,
Volume 19, Issue 73 (fall 2015)
Abstract
Due to the time and space changes of hydrological events in the arid and semi-arid regions, recharge measurement in these areas is very difficult. Hence, groundwater recharge is a complicated phenomenon for which there is not a fixed method to determine. The aim of this research was to develop a method for estimation of groundwater recharge based on a hybrid method. In this study, a hybrid method for calculating recharge was presented by combining empirical methods with a mathematical model, MODFLOW, and AHP analysis. The results showed that the most important parameters affecting groundwater recharge are soil properties, unsaturated thickness, land cover, land slope, irrigation and precipitation, from which the soil properties and precipitation are most important. The results showed that the overall impact of small changes in precipitation and temperature significantly affect the groundwater recharge, and heavy soils are much more sensitive to these changes than light soils. By changing 10% precipitation, the recharge rate is changed between 16% and 77% and by changing 1ºC temperature, the recharge rate is changed between 6% and 42%. Also, results showed that precipitation and evapotranspiration changes in four months including December, January, February and March had significant effects on annual recharge rate. Using the results of this research, the vulnerable areas of the plain, appropriate places and time for artificial recharge could be identified. Overall, the results of this study can be useful in various aspects of groundwater management.
S. S. Okhravi, S. S. Eslamian, N. Fathianpour, M. Heidarpour,
Volume 19, Issue 74 (Winter 2016)
Abstract
In addition to kinematic description of biological reaction, flow pattern plays an important role in designing constructed wetlands. This study investigates the effects of flow distribution on constructed sub-surface horizontal flow wetland with a length of 26 m, width of 4 m and 1% bed slope in order to understand internal hydraulic functioning patterns. Inlet configuration is selected as a variable parameter. Three different cases of inlet and outlet configurations were 1) midpoint, 2) corner, and 3) uniform. Outlet has been fixed in all configurations. Uranine tracer was used to determine the influences of flow distribution by drawing hydraulic retention time curve in different cases. Results showed that mean residence times for each configuration were equal to 4.53, 3.24 and 4.65 days, respectively. Retention time distribution curve provided conditions, not only for showing dispersion patterns throughout system but also for interpreting hydraulic parameters like hydraulic efficiency and effective volume. According to the retention time curve, effective volume was 87.5% in configurations 1 and 3, and 62.1% in configuration 2 following numerous short-circuiting ratios. Finally, the best configuration of inlet-outlet layout to improve the performance of effluent treatment and use the geometry effectively was found to be the uniform-midpoint based on physical experiments followed by midpoint–midpoint as the second best.
P. Asadi Alasvand, A. Heidari,
Volume 19, Issue 74 (Winter 2016)
Abstract
Technosols are modified soils affected by human activities. This study investigated genesis, classification and physicochemical properties of four pedons of Technosols developed on refused oil refinery materials and compared them with two unpolluted pedons. Mineralogical studies showed smectite as a dominant clay mineral with other clay minerals. These clay minerals adsorb oil compounds in their interlayer spaces and reduce their mobility and decomposition. Different micromorphological features resulting from oil compounds in soils, including depletion zones, types of coatings (quasi and hypocoating) and features due to horizontal and vertical movement of oil compound in soil showed dynamics of oil compounds and their effects on soil forming process. The refused petroleum compounds decrease pH and increase organic carbon, amorphous form of Iron in soils. Taking into account the presence of high amounts of gypsum and carbonate in polluted soil, the studied soils were classified as Typic Calcigypsids in Soil Taxonomy but in WRB system, due to the presence of impermeable geomembrane within 100 cm of soil surface, they were classified as Linic Technosols, showing the more precision of WRB system in their classification.
N. Zohrabi, A. Massah Bavani, E. Goudarzi, M. Heidarnejad,
Volume 20, Issue 77 (Fall 2016)
Abstract
Since climate change is regarded as a serious threat to different parts of life cycle, separation of factors intensifying this phenomenon seems necessary. This research has investigated the temperature and precipitation trend using the multiple trend test in the upstream Karkheh basin located in west of Iran. For this purpose, two-dimensional graphs of temperature and precipitation anomalies of the CGCM3 Model (1000-year data) were drown for the study area. Then, the attribution of changes in climate variables due to climate internal fluctuations or greenhouse gases affected by human factors were investigated. Based on the findings of this study, in different parts of the study area, the range of natural climate variables for temperature and precipitation changes (95% probability) in the west of the study area are
± 1.4ºC and ±76%, respectively.
The results showed increase and decrease in temperature and precipitation in most of the studied stations, respectively. The variables of temperature and precipitation are affected by climate change and as we approach latest years, especially in the western and central parts of the study area, the impact of greenhouse gases in increasing temperature and reducing precipitation becomes more evident. According to the current results it can be concluded that changes in land use in Iran caused by human interventions can be introduced as a significant factor for the ascending trend of temperature. However, it can be noted that the most important factors of the increased greenhouse gases in recent years are human activities such as land use changes. These changes certainly have affected water resources in the study area.
A. Haghshenas-Adarmanabadi, M. Heidarpour, S. Tarkesh-Esfahani,
Volume 20, Issue 77 (Fall 2016)
Abstract
In this paper, the efficiency of four hybrid horizontal-vertical subsurface constructed wetlands which have been built for the tertiary treatment of Isfahan North Wastewater Treatment Facility and removal of organic matters was evaluated. In these constructed wetlands three plants including Phragmites australis, Typha latifolia and Arundo donax were planted and one unit left unplanted. The results of 12 months of sampling showed that the type of vegetation has no significant influence on the organic matter removal in the subsurface constructed wetlands, although the removal efficiencies in the planted constructed wetlands were more than unplanted control one. The COD and BOD5 removal efficiency in the constructed wetlands changes between 77% to 83% and 84% to 86%, respectively, during the operation period. The results of this research also showed that the organic matter removal was dependent on the influent organics nature and biodegradability. The first order model constants were calibrated in different wetlands for designing main projects. The organic concentration in the wetland effluents met the Iranian regulation limits for different reuse applications that shows the constructed wetland is a suitable technology for wastewater treatment in Iran.
A Heidari, H. Haji Agha Alizadeh, A. R. Yazdanpanah, J. Amiri Parian,
Volume 20, Issue 78 (Winter 2017)
Abstract
Traditionally, most corn field in Hamedan Province is prepared for planting by moldboard plowing followed by a number of secondary tillage operations. In recent years conservation tillage systems have become more popular. This research was conducted in the form of a split plot experimental design with six tillage treatments and three replications. Main tillage methods including: (T1) conventional tillage (moldboard plow + cyclotiller equipped with roller), (T2) combination tiller (chisel plow equipped with roller) (T3) bandary tillage with chisel blades were considered as main plots and two P fertilizer application including: (F1) fertilize broadcasting and (F2) fertilizer bandary placement were considered as sub plots. During growing seasons, soil mechanical resistance (cone index), soil bulk density and water infiltration in soil were measured. At the end of the growing season (harvesting time), corn yield and its components were measured. Results indicated that tillage methods and soil depth had a significant effect on the soil bulk density and cone index. The effect of tillage on water infiltration in soil was significant. The effect of P fertilizer application on corn yield was significant (P≤0/01) and P fertilizer bandary placement with mean corn yield of 10862 kg/ha had higher yield value than the fertilizer broadcasting with mean corn yield of 9965 kg/ha. Although the difference between tillage methods for corn yield was not statistically different, T2 treatment with mean corn yield of 10913 kg/ha had higher yield value than the other two tillage treatments (T1 with mean corn yield of 10106 kg/ha and T3 with mean corn yield of 10222 kg/ha).
Mr A. Nouri Imamzadehei, Manouchehr Heidarpour, M. R. Nouri Imamzadehei, B. Ghorbani,
Volume 21, Issue 2 (Summer 2017)
Abstract
Flood currents are considered threatening factors by creating local scour along bridge piers. One method for decreasing local scour is to strengthen the bed against imposed tensions. Among methods which can directly be appropriate in decreasing and controlling local scour of bridge piers is to employ geotextile around bridge piers. In the present study, the effect of geotextile layer in decreasing local scour of cylindrical single-pier was investigated with the purpose of proposing the best effective method of covering bridge pier. So, layers with circular and oval shapes were put around the pier, in proportion with pier diameter, and the performance of each was compared with the unprotected pier. Test results showed that with installing the oval geotextile layer, final scour depth around the pier reached to 1.25D. Also, comparing geotextile and collar with 2D diameter, the delay of scour process around geotextile was 40 times higher than the collar, but the collar decreased the ultimate scour depth further than geotextile.
F. Heidari, K. Shirani, R. Saboohi,
Volume 21, Issue 3 (Fall 2017)
Abstract
The Ab-Barik watershed in Bam is a part of Lut desert basin. It is like all other desert areas which has erosion problems caused by wind erosion, sand and soil storms. The result of these sand storms appears as continuous and isolated sand hills. In this paper it was attempted to identify direction and source of harvest points by using sedimentological methods. This was accomplished by step by step sand processed method. At the first step the main direction of harvest areas was determined by some studies such as collecting public information, the study of general morphology and measuring sand hill, comparison of aerial photos in different periods and analysis of region winds. At the second step the origin of sand areas was recognized by investigations such as the study of geomorphological facies of lands of harvest regions with emphasis on morphodynamic wind, granulation of sand hills elements and surface soil of erosionic facies plots at harvest lands, study of morphoscopy of forming particles of samples and determination of indices including central diameter, roundness, sorting and mineralogy of samples. The results revealed that the main source of sands is clay pan facies and farm lands, especially waste lands. Also, the main direction of harvest areas displacement is from south, southwest to north, and northeast. Application of results of this study can modify the used management methods, controlling and confronting with the problem of wind erosion and sand and soil storms.
Z. Heidari, M. Farasati, R. Ghobadian,
Volume 22, Issue 2 (Summer 2018)
Abstract
To design cost-effective and efficient drip irrigation systems, it is necessary to know the vertical and horizontal advance of the wetting front under the point source; also, the proper management of drip irrigation systems requires an awareness of the soil water distribution. Many factors influence wetting pattern dimensions, including discharge, land slope, irrigation time and soil texture. The purpose of this study was to investigate the applicability of the support vector machine in simulating the wetting pattern under trickle irrigation. After preparing a physical model made of Plexiglas with specific dimensions and filled with silty clay loam soils, experiments were conducted in the irrigation laboratory of Razi University, Iran, with emitters of 2, 4, 6 and 8 l/hour discharge during the irrigation intervals of 2 hours and 24 hours redistribution and 0,5,15 and 20% slope with three replications. In this study, the statistical indicators R2, RMSE, MBE and MEF were used. R2 values for the wet depth, width and area were 0.96, 0.96 and 0.92, respectively. Regarding the MBE value, the SVM model estimated the wet width and depth parameters to be 3% less than the actual value, and simulated the wet area 2.04% less than the real value. Also, according to the MEF and RMSE values, the SVM model simulated the wet area parameter with more error. Overall, the results showed that the SVM model had a high ability to estimate the wetting pattern parameters.
E. Gravandi, A. Kamanbeadst, A. R. Masjedi, M. Heidarnejad, A. Bordbar,
Volume 22, Issue 3 (Fall 2018)
Abstract
Rivers has long been regarded as one of the most basic human water supplies. If the topography, a morphology, water requirements conditions, etc. allow water to be transferred to gravity, the use of the dike can have a significant impact on the flow rate and the sediment input to Intake. Dike design needs to consider several parameters such as position, length, type, etc. Using a good design can increase the input flow rate and reduce the sediment entering it. In this study, to evaluate the dike impact on flow hydraulic conditions in the Intake with different situations, 30, 45, 60 and 90 degrees two simple L-shaped dikes in the upstream and downstream Intake and for five inlet flows (0.7, 1.12, 2.84, 5.04 and 6.23 Lit/s) were considered in the laboratory flume made by the author as a physical model to simulate the flow of the basin; then different effects of the dike on the hydraulic flow were studied. The results of the tests showed that the L-shaped dike in the upstream and downstream Intake in the internal arc flume increased the inflow flow rate into the Intake. Also, the best angle of deviation for the maximum flow entered the Intake angle of 60 degrees.
R. Monjezi, M. Heidarnejad, A. R. Masjedi, M. H. Pourmohammadi, A. Kamanbedast,
Volume 23, Issue 2 (Summer 2019)
Abstract
Nonlinear weirs are regarded as important hydraulic structures for water level adjustment and flow control in channels, rivers and dam reservoirs. One example of non-linear weirs is shaped as curved-zigzag. The crest axis of these weirs is non-linear. At a given width, the crest length is greater than that of the conventional linear weirs. Thus, they achieve a higher flow rate for an identical hydraulic load. This research experimentally focused on the discharge coefficient and flow rate of curved weirs with three different curve radii in two triangular linear and zigzag shapes. The discharge coefficients of these weirs were comparatively explored in terms of the hydraulic performance as a function of the total hydraulic load to weir crest height ratio (hd/P) and curvature angle (θ) (or curve radius). The results indicated that for the same hydraulic load, the increase of θ (the decrease in curve radius) led to a lower discharge coefficient; this was first because of the increased topical rise of water level, and then the more indirect path with a greater curvature through which the flow had to transport. Both factors could negatively affect the water discharge coefficient. In practice, the runoff coefficient at a weir with a curve radius of R/w=1.25 was approximately 8.5% greater than that of a weir with a curve radius of R/w=0.75 under a hydraulic load of 0.2.
H. Davodi, A. R. Masjedi, M. Heidarneja, A. Bordbar, A. A. Kamanbedast,
Volume 23, Issue 2 (Summer 2019)
Abstract
In this study, some experiments were carried out in a rectangular plexiglass flume to study the effect of the cable around a vertical tripod and two piles groups with different angles. In this research, a series of experiments were performed by placing a cylindrical vertical pileand two piles groups with different angles separately in two modes including with cable and without cable. The experiments were carried out using three types of cable with various diameters, number of threads and thread angles at a constant discharge in clear water. In each experiment, scour depth at the end of the test was measured; then, the scour depth was calculated in different conditions using the obtained data. The best configuration in the vertical pier and piers group was found for the cable-pier diameter ratio of 0.1, the thread angle of 15° and the triple threads. The result indicated that the scour reduction was enhanced as the cable diameter and threads were increased and the thread angle was decreased. So in the piers group of 28 and 38°, scour depth was reduced to about 43, 49 and 56%.
