Showing 183 results for Type of Study: Original Research
Ehsan Pegah,
Volume 17, Issue 2 (9-2023)
Abstract
The ratios of elastic anisotropy in cohesionless soils are always of substantial importance in respective analyses to the geotechnical and geological engineering projects. These ratios are raising from the available discrepancies in anisotropic elastic parameters ascribed to the different directions and planes of soil mass. The major objective of this study is to recognize the variations range of anisotropy ratios resulting from anisotropic shear and Young’s moduli for a variety of cohesionless soils followed by assessing the potential relations among these two anisotropies. To this end, by assuming the transversely isotropy in cohesionless soils, the anisotropic elastic constants from 266 conducted laboratory tests on 37 various soil specimens relating to 10 different sands were derived from conventional triaxial and seismic waves laboratory tests coupled with the numerical testing results in literature. By sorting the collected data and subsequently their analyses, at the first stage, the values of shear and Young’s moduli anisotropy ratios were calculated for the studied soils. Furthermore, by plotting the anisotropy ratios in several joint panels and performing a series of regression analyses on the resulting values, the possible dependencies were inspected between these two anisotropies. At last, the indicative equations among shear and Young’s moduli anisotropies were developed with insistence on use of which instead of the former similar relations in literature.
Dr Asghar Milan, Mehran Shafiei,
Volume 17, Issue 2 (9-2023)
Abstract
Calculating the volume of earthworks in mines is one of the challenging, costly, and time-consuming issues in the field. In mining projects, it is necessary to calculate the volume of excavation to estimate the volume of extraction in order to plan the sale of the produced products and to calculate the cost performance of the contractors. The calculation of excavation volumes presents many challenges, such as the selection of the best measurement tool and technique, the need to adjust maps produced in different time periods, the existence of inflation coefficients and the volume to weight conversion factor. Today, tools such as laser scanners, total stations and metric cameras are used to calculate earthwork volumes. However, they are expensive to use and require an experienced operator. Therefore, there is a need to investigate methods to calculate volumes in less time with acceptable accuracy. This research evaluated the use of smartphones for optimal volume estimation of earthworks. In this research, the image data obtained from the smartphone was processed with a technique based on structure from motion (SFM) and the results were used to create a digital terrain model to estimate the volume of earthworks. The calculated volume differences for the earthworks volume compared to ground methods for a soil mass and the studied excavation are 3.86% and 1.84% respectively, which shows that the method used in this research has the necessary accuracy to calculate earthworks volumes and considering the many advantages it has over traditional methods in terms of cost and time, it can replace them.
Tahereh Azari, Sakineh Dadashi, Fatemeh Kardel,
Volume 17, Issue 2 (9-2023)
Abstract
Qualitative assessment of coastal waters affected by seawater salinity can be done using the parameter of chloride in groundwater. This research proposes a supervised artificial intelligence committee machine (SAICM) method for accurate prediction of chloride concentration in groundwater of Sari plain. SAICM predicts chloride concentration as the output of the model by non-linear combination of artificial intelligence models. In this research, Principal Component Analysis (PCA) method was used to identify effective hydrochemical parameters related to chloride concentration as input components to artificial intelligence models. Based on the results of PCA, parameters (Na, K, EC, TDS, SAR) were selected as input components of artificial intelligence models. Firstly, four artificial intelligence models, Sogno fuzzy logic, Mamdani fuzzy logic, Larsen fuzzy logic and artificial neural network were designed to predict chloride concentration. Based on the modelling results, all the models showed a good fit with the chloride data in Sari Plain. Then, the combined SAICM model was built, which combines the prediction results of 4 separate AI models using the nonlinear ANN combiner and determines the chloride concentration more accurately. The results show that the proposed SAICM can estimate chloride concentration with much higher accuracy than individual methods.
Mr. Mehdi Hashemi, Dr Davood Fereidooni,
Volume 17, Issue 2 (9-2023)
Abstract
In this research, the durability and deterioration of two historical stone monuments, including the Dashkasan rock temple and the historical stone inscriptions of the Sojas cemetery in the south of Zanjan province, were investigated. For this purpose, two stone block samples were selected from each historical work for laboratory study. Based on the geological investigations, the historical monuments of the Dashkasan rock temple were carved on tuffs of the Karaj Formation. According to the thin section study, the Dashkasan temple rocks composed of the crystal vitric tuff and lithic vitric tuff and the samples of the historical inscriptions of the Sojas cemetery were limestone and very fine-grained sandstone, quartz being the dominant mineral of these rocks. In terms of physical characteristics, the samples studied have medium density and porosity. In terms of durability and deterioration, all four samples were subjected to 15 cycles of the slake durability test in normal water and sodium sulphate solution. The degradation function model and half-life of all four samples were determined and analysed. The results show that all four samples have a lower slake-durability index in sodium sulphate solution than in normal water. Due to the presence of quartz in lime or clay matrix, the samples of historical stone inscriptions from Sojas cemetery have more water absorption and porosity and are more durable, and their half-life is lower than the samples from Dashkasan rock temple.
Somayeh Zarei Doudeji, Rahim Bagheri, Hadi Jafari,
Volume 17, Issue 2 (9-2023)
Abstract
The science of system dynamics is a management tool capable of simulating complex systems in water resources. In this research, the model of the dynamic system of multi-purpose consecutive Kardeneh-Sana dams located in Bushehr province has been simulated. The purpose of this modeling is to realize the different needs of the dam (drinking, environment and industrial agriculture) before its construction and also to investigate the effect of construction of the upstream dam on the supply of the downstream dam. The results were studied after calculating the annual and monthly percentage of volume and time supply of the different needs and source of supply, as well as considering two drinking water wells to provide drinking water in the months when the dam is not able to provide drinking water and the maximum The discharge of the current drinking water pipeline of the region was carried out. Six management scenarios were considered for modeling, and finally the sixth scenario was considered as the most optimal scenario. In order to evaluate the model, the simulated values were compared with the observed values of the water volume of Sana Dam. The results indicate that the volume supply of drinking, environment and industrial agriculture needs of Kardeneh Dam is 97.66, 96.59 and 82.76 respectively, and also the volume supply of environment and agriculture needs from Sana Dam is 100, 48 respectively. It is 83.0%, which is within the acceptable range of the Ministry of Energy. Based on this research, it was determined that by modeling based on model evaluation indicators including percentage of volume supply and percentage of time supply of different needs, it is easy to determine the effect of management and exploitation policies on the way of determining and allocating resources. Water observed and made the most optimal decision.
Massoud Morsali,
Volume 17, Issue 3 (12-2023)
Abstract
Tunneling in a saturated environment and the intrusion of groundwater flow into tunnels during excavation is one of the most serious problems in tunneling projects. Water ingress into the tunnel can lead to damage to tunnel construction equipment, personnel, the excavation process, etc. The hydrogeological studies of the springs along the tunnel route and the estimation of the water entering the tunnel also investigate the possibility of drying up or reducing the water level of the tunnel route. The hydrogeological studies of the springs along the tunnel route and the estimation of the water inflow into the tunnel will also examine the possibility of drying up the springs or reducing the water level of the tunnel route. On the other hand, the complications of water ingress into the tunnel and the lack of an accurate and appropriate method increase the importance of these studies. Experimental and analytical methods are available to predict water inflow into a tunnel. In this article, in addition to presenting the general process of carrying out hydrogeological studies of tunnels, the weight percentage of hydrogeological studies and the problems associated with them are discussed. On average, more than 30% of all tunnel problems are related to groundwater, but less than 5% of studies are carried out in this field. The disproportionate weight of the above two cases and its causes are among the other cases discussed in this article.
Mister Hamzeh Torkamanitombeki, The Doctor Mashalah Khamehchiyan, Mistress Maryam Nazari, Mister Shazdi Safari,
Volume 17, Issue 3 (12-2023)
Abstract
The purpose of the research is to investigate the risk of liquefaction risk at the beaches of Bustano in the western part of Bandar Abbas in Hormozgan province. The periodic stress method was used as the method to evaluate the liquefaction potential based on the data obtained from Standard Penetration Test (SPT). The acceleration of 0.35 g was chosen as the maximum acceleration of the bedrock, and cross sections were extracted using Rockwork software. From an engineering geological point of view, the characteristics of the sedimentary deposits and the collected geotechnical information were analyzed to generate geotechnical index profiles. As the study area is located at the edge of the folded Zagros, seismically it has the characteristics of the Zagros-Makran transition zone which basically exerts the most pressure on the saturated sediments of the area. Due to the strong movement of the earth in generating liquefaction, the seismic bedrock acceleration (PGA) and the maximum horizontal acceleration at the ground surface (amax) were evaluated by liquefaction analysis using LiqIT v.4.70 software. The results indicate that the sandy and silty sediments of the study area are the outcome of the weather changing processes at the northern altitudes of the region. Granular sand and silt sediments were found under favorable conditions with high groundwater level, confirming the presence of liquefaction phenomenon in the area. Zoning maps of the intensity of liquefaction were extracted at the surface and at depth were obtained in different parts of the Bustano, indicating the different classes of risk of liquefaction in the soil of this area. In general, the occurrence of liquefaction with high intensity liquefaction was predicted for the Bustano area.
Professor Hamidreza Nassery, Koosha Tamimi, Dr Farshad Alijani, Dr Sadegh Tarigh Azali,
Volume 17, Issue 3 (12-2023)
Abstract
The development of underground transportation activities in cities, such as tunnel boring, may exert short-term or long-term effects on the groundwater and springs of such areas. The construction of the tunnel of Tehran Metro Line 6 (TML6) through alluvium and carbonate rocks of Ali Spring has aroused concern due to the caused fluctuations in discharge and temporary dryness of the spring. The hydrochemical properties of the groundwater and catchment area were investigated to find a connection between the aquifers around the spring and determine the major aquifer feeding it. The estimated volume of water penetrated to the tunnel and the most greatly affected area by the water leakage into the tunnel was determined using analytical methods of water leakage into the tunnel and the DHI method. The statistics for precipitation with the changes in the discharge of the spring before and after the excavation of the metro tunnel were compared to evaluate the changes in the discharge of the spring with the precipitation in the area. The results showed that the metro tunnel excavation has dramatically affected the hydrological system of the area and discharge of the Ali Spring. Moreover, continuing the extraction may produce adverse effects on the discharge of other springs and wells and alter the flow system of the area temporarily or forever.
Khandani, Atapour, Yousefi Rad, Khosh,
Volume 17, Issue 3 (12-2023)
Abstract
Backfill materials used to fill underground mines are a type of engineered material whose particle size distribution (PSD) directly affects their mechanical and physical properties. According to the authors' review, there is no comprehensive standard for the properties of aggregates used in underground mine backfill materials. In this paper, the particle size ranges and particle size distribution curves of various mine backfill materials, including hydraulic backfill, paste backfill and rock backfill, have been reviewed. The available data on different types of backfill materials were collected. Based on the collected data, the smallest particle size, the largest particle size and the PSD curve ranges for each type of backfill material were determined. Then the characteristics of the particle size distribution curve of each backfill material, including the mean particle diameter (D50), the uniformity coefficient (Cu) and the curvature coefficient (Cc), were calculated. The results of the analysis of the PSD curves for paste backfill, hydraulic backfill and rock backfill materials showed that the particles in rock backfill and paste backfill had the largest and smallest sizes, respectively. Finally, the particle size distribution characteristics of a new backfill material prepared from construction and demolition waste (CDW backfill) are presented and compared with the particle size distribution of each of the conventional backfill materials. The results indicate that the PSD curve of the CDW backfill lies at the upper limit of the range of the particle size distribution curve of hydraulic backfill and at the lower limit of the range of the particle size distribution curve of rock backfill.
Miss Faeze Majidi, Dr Mohammad Fathollahy, Engineer Habib Rahimi Menbar,
Volume 17, Issue 3 (12-2023)
Abstract
Aggregate is the main component of concrete and plays an essential role in the quality of concrete. Alkaline silicate reaction (ASR) is one of the most important reactions in concrete that can lead to concrete destruction. Aggregates containing active silica are responsible for this reaction, and the higher the amount, the greater the expected volume of reactions. The rate of increase of the reactions with changes in the amount of silica aggregates is part of the subject of this research. In this regard, a material was selected as the base material from the mountain quarry, and the necessary tests were performed on it by adding silica aggregates, 5, 10, 15, and 20 percent, the ASR test was performed on them according to the ASTM C1260 standard; The results showed that the expansion of the samples will increase by 0.01, 0.02, 0.04 and 0.06% respectively. Next, for the effect of microsilica on ASR, 5, 10, 15, and 20% were added to the materials and the results showed that microsilica reduced the expansion of the samples by 0.009, 0.014, 0.022, and 0.032 respectively and the increase of 20% of microsilica has reduced the expansion of the samples by 50%.
Amin Ahmadi, Gholamreza Mirzavand, Maryam Zebarjad,
Volume 17, Issue 3 (12-2023)
Abstract
The zone of influence of the well is the area where the activity of the well changes the water level. The zone of influence is important in determining the protection zones; however, in this regard, reliable relationships have not yet been presented and their lack of relationship has not been confirmed; and this is due to the lack of accurate knowledge of the zone of influence in some aquifers. This study was carried out using the MODFLOW model to know the effect of aquifer physical parameters on the drawdown cone in an unconfined alluvial aquifer with a sloping water surface; and since no such research has been reported so far, the results are innovative. The results showed that although it is possible to ignore the effect of a well in parts of the aquifer due to measurement and presentation limitations, in practice the influence zone of each well will extend to the outer physical boundaries. It was found that two types of real and theoretical drawdown cones can be discussed in the influence zone and each should be analyzed separately. It was found that parameters such as hydraulic conductivity, saturation thickness, transmissivity, horizontal anisotropy, bed slope, and amount of recharge in sloping unconfined aquifers have a dual effect on the drawdown cone, and if their high values decrease the drawdown in short distances, they increase the drawdown in long distances. It was found that normal heterogeneity does not change much on the drawdown cone, and the reason is the opposite effects of hydraulic conductivity and specific yield on the drawdown value. It was found that hydraulic conductivity, horizontal anisotropy and specific yield have a strong effect, but vertical anisotropy and heterogeneity have a negligible effect on the drawdown cone.
Hossein Mohammadzadeh, Vahid Naseri Hesar, Hamid Ghalibaf Mohammadabadi,
Volume 17, Issue 4 (12-2023)
Abstract
Due to the complex hydrogeology of karst areas, the sealing of dams in such areas is more difficult, time-consuming and expensive, and the possibility of water leaksge is higher. After the dewatering of the Gharetikan dam and appearance of downstream springs and the leakage of water from the abutment of the Tirgan limestone formation, the possibility of karst development is considered to be the most important problem of this dam. In this article, the potential of karst development in the area and supports of the Gharetikan Dam has been studied by carrying out geological studies, structural geology and joint studies, geotechnical permeability and analysis hierarchy method (AHP).. The results show that about 14.6% of the Gharetikan dam area has a high potential for karst development. The area of Gharetikan dam area is affected by the Sarroud fault zone system, which has caused the collapse of the left side of the dam axis. The joint studies in the abutment of Gharetikan dam show three main types of joints. Two groups of joints are located at the intersection with the dam axis and the slope of the other group of joints is towards the dam basin. The investigating of Lugeon permeability tests in the dam construction shows that the highest permeability can be seen in the left abutment with turbulent flow, and then under the river bed with linear and turbulent flow, but there is no permeability in the right abutment. And the flow is mostly linear. According to the structural-conceptual model prepared from the location of the Gharetikan dam, to the location of the dam axis in the Sarroud fault system, and the amount opening and the slope direction of the joints in each station, it is expected that the amount of water leakage and escape and the possibility of karst development from the left side and the bed of the dam will be more than the right side of the dam.
Dr Seyed Yahya Mirzaee, Phd Student Roghayeh Amiri, Dr Manouchehr Chitsazan,
Volume 17, Issue 4 (12-2023)
Abstract
This study investigates the effects of climate change on the Khorramabad Central Plain aquifer. The climatic variables of temperature and precipitation were studied and downscale using GCM and LARS-WG models for a 45-year base period (October 1971 to September 2015). Temperature and precipitation values were then projected for a 30-year period (October 2024 to September 2054) under the climate scenarios SSP1.2.6, SSP2.4.5 and SSP5.8.5. The rainfall runoff simulation was carried out in the Khorramabad basin using the IHACRES model. The groundwater flow in the central plain of Khorramabad was calibrated using MODFLOW code for a period of 120 months (October 2010 to September 2020). This model was validated for a period of 36 months (October 2020 to September 2023). According to the results, the values of precipitation in the future period compared to the base period will decrease by 42.6, 47 and 61.9 mm in the scenarios SSP1.2.6, SSP2.4.5 and SSP5.8.5 respectively. The annual mean of minimum and maximum temperatures increases in all three scenarios. After calibration of the IHACRES model, NSE=0.74, RMSE=1.46 and R2=0.64 were obtained. According to the results, the predicted discharge of the Khorramabad River in the future period will increase by 2.38 m3.sec in the SSP1.2.6 scenario and decrease by 0.42 and 0.94 m3.sec in the SSP2.4.5 and SSP5.8.5 scenarios, respectively, compared to the base period. The average 30-year aquifer balance under the SSP1.2.6, SSP2.4.5 and SSP5.8.5 scenarios was 27494.5, -12335.3 and -41823.3 m3, respectively. The groundwater level of the Khorramabad Central Plain aquifer will decrease in the future period.
Hossein Ebrahimi, Farzad Akbari, Soroor Mazrae Asl, Babak Biglari,
Volume 17, Issue 4 (12-2023)
Abstract
The Vorskharan karst spring with a catchment area of 50 square kilometers and an average discharge of about 1.35 m2/s is one of the most important springs in the city of Firouzkouh. In order to asses the hydrogeological and hydrogeochemical charachteristics of the spring, the physical and chemical properties of the spring water were measured and analyzed for several months. The results showed that the recession curve of the spring has a slope and the value of its coefficient is about 0.003. The low coefficienof the discharge variation t, electrical conductivity and major ions, as well as the single slope of the spring’s recession curve , are mainly due to the elongated shape of the aquifer and the long-term presence of snow in the catchment basin of the spring. Considering the relatively high water level of the spring and the existence of a sinkhole and a polje in the spring’s catchment area, as well as the coefficient of small changes in the physical and chemical parameters of the spring, it can be said that the dominant flow system in the aquifer which recharges Vorskharan spring,is conduit-diffusive. According to the field studies and the evaluation of the percentage of soil cover, the development of dissolved spaces and other morphological effects of karst, the percentage of annual recharge in the catchment area was estimated at 56%. With the amount of precipitation, the percentage of annual recharge, the annual recharge volume of the preliminary water catchment basin equal to 19.2 MCM and the annual discharge volume of the spring through the annual hydrograph of the spring was calculated to be equal to 20.1 MCM. It was also observed that the type of water is Ca-HCO3, and the lithology of the aquifer is calcareous and dolomite.
Prof. Mohammad Nakhaei, Dr. Amin Mohebbi Tafreshi, Dr. Tofigh Saadi,
Volume 17, Issue 4 (12-2023)
Abstract
A sharp drop in groundwater level as a result of indiscriminate extraction over a long period of time leads to the drying up of groundwater flows, which is called the phenomenon of groundwater drought. In this regard, this research aims to investigate the process of change and reduction of groundwater level, which is characterised by the phenomenon of groundwater drought. Based on this, the Groundwater Resource Index (GRI) was used to evaluate the drought condition of groundwater and analyse its spatial and temporal patterns based on groundwater level data of 21 observation wells between 1993 and 2019. ArcGIS software was used to create zone maps. The results of the research show that certain areas of the study area have experienced moderate to severe drought since 2001. In addition, the GRI zonation maps show that the southern and south-eastern regions of the aquifer have been more sensitive to drought than other parts of the aquifer during the defined period. The spatio-temporal pattern of groundwater drought in the aquifer shows that after a period of moderate drought from 2001 to 2003, the condition of the aquifer improved slightly, and generally stable conditions were established from 2001 to 2010, but since 2011, the occurrence of drought has intensified and the aquifer has been in severe to very severe drought conditions. These conditions highlight the need for careful attention and implementation of management measures. One of the study's recommendations is to use satellite data on groundwater levels to assess the progress of the drought, and compare it with the findings of this study.
Dr Masoud Amelsakhi, Eng Elham Tehrani,
Volume 17, Issue 4 (12-2023)
Abstract
This research is a laboratory study to improve the geotechnical properties of sandy soils. Concrete waste with a grain size of 1.2 to 1 inch was used for this purpose. The effect of using concrete waste at 0, 10, 20 and 30 weight percent on dry sandy soil in two loose and dense states was investigated. Based on the results of the direct cutting test, the addition of concrete waste has increased the shear strength and the internal friction angle of the soil; The loose samples made with ٪30 of concrete waste had the greatest effect, so adding ٪30 of concrete waste to loose sand increased the internal friction angle of the soil by ٪32 and the shear strength by ٪42 Similarly, adding ٪10 of concrete waste to dense sand increased the internal angle of friction of the soil by ٪4 and the shear strength by ٪6.
Majid Dashti Barmaki, Zahra Yazdani Barmaki, Massoud Morsali,
Volume 17, Issue 4 (12-2023)
Abstract
In order to design and optimize the quality monitoring network in areas with several sub-basins, it is necessary to know the criteria that affect them, so that in each sub-basin the presence or absence of a monitoring station and the required parameters can be determined. In this respect, the use of the surface water pollution index, namely WRASTIC, can be effective. The WRASTIC model is a practical and advanced method for assessing the risk and potential of pollution in sub-basins. Due to its role in the drinking water supply of the city of Bandar Abbas, monitoring the quality of the Shamil-Takht study area is very beneficial. Therefore, to assess the risk of pollution in this plain, the basin was divided into 16 sub-basins using Global Mapper software. The WRASTIC index was presented as different layers of information, and its value was calculated for each sub-basin by rating by expert judgement method, weighting by hierarchical analysis method, and merging layers using weighted overlap. The results showed that three sub-basins have high risk and three sub-basins have low risk. Then, according to the condition of the streams in each sub-basin, the pollution index and its importance, the number of quality monitoring stations and the necessary parameters in this area were determined. Accordingly, five stations were added to the existing ten hydrometric stations at different locations. In the final 15 stations, the measurement of general parameters and major ions was included in the proposed agenda. The measurement of parameters such as phosphate/phosphorus and nitrate/nitrite was also included in six sub-basins, and heavy metals in three sub-basins.
Eng. Zahra Soleimani, Dr. Ebrahim Rahimi, Dr. Houshang Khairy,
Volume 18, Issue 1 (5-2024)
Abstract
This article deals with the strength evaluation of concrete obtained by adding different percentages of three types of nanominerals, including nanocalcite, nanobarite and nanofluorite. To measure the velocity of ultrasonic waves and compressive strength of concrete, 15×15×15 cm cube samples were prepared with 7-, 28- and 90-days curing. 10 types of mix designs with 0.39 water-cement ratio, including the control sample (without additives) and the samples with 0.5, 0.75 and 1% nanominerals were subjected to the mentioned tests. The results showed that the addition of nanocalcite, nanofluorite, and nanobarite with values of 0.75%, 1%, and 0.75%, respectively, have the highest compressive strength compared to the control sample. Although these do not have pozzolanic properties, they play a positive role in increasing the concrete strength by filling concrete voids and due to their high specific gravity, increasing concrete density.
Miss Sooror Mazraeasl, Mr Farzad Akbari, Ms Elahe Iraniasl, Miss Leila Hosseini Shafei,
Volume 18, Issue 1 (5-2024)
Abstract
Groundwater is one of the main sources of water supply for agriculture, drinking and industry in Iran, especially in areas with arid and semi-arid climates. Therefore, due to the high importance of groundwater resources, it is necessary to know the hydrodynamic parameters in order to determine the natural flow of water and manage the optimal utilization of groundwater resources. Considering the role of the Daloon-Meydavood aquifer in providing part of the water needed in the study area, especially for agricultural purposes, the hydrodynamic parameters of this aquifer were estimated using the methods of grain size analysis, geophysics and pumping test. The parameters were calculated by all three methods and validated using the flow rate of the exploitation wells. In all three methods, the hydrodynamic parameters (Hydraulic conductivity, Specific yeild, transmissivity coefficient) are the highest in the north and northeast and the lowest in the south and northwest. The results showed that 2 methods including grain size analysisand pumping test had the most similarity with the discharge map of the exploitationwells.
Somayeh Zarei Doudeji, Rahim Bagheri, Hadi Jafari,
Volume 18, Issue 1 (5-2024)
Abstract
Groundwater resources in Iran are of particular importance due to the lack of surface water resources, lack of precipitation, high evaporation volume and recent droughts. The first step in identifying and exploiting groundwater resources is its quantitative and qualitative investigation. Neyriz watershed, located in the study area of Qatroiye desert, has 17 piezometers, whose groundwater level has been recorded monthly during the statistical period of more than 12 years. Investigations of the groundwater level and the map of the flow lines show the anomaly of the flow in the south and southwest part of the aquifer, which shows the direction of the groundwater flow contrary to the direction of the topography of the area. In this research, an attempt was made to investigate the cause of this anomaly based on the available information, including piezometer drilling logs, aquifer quality data, and national statistical data. Based on the qualitative information of the aquifer, the electrical conductivity and chlorine values of the groundwater increase in the direction of the topographic slope, which indicates the flow in the direction of the topographic slope. Qualitative charts of Piper, Schuler and Durov also confirm this issue. The level of groundwater in selected exploitation wells for qualitative sampling based on the information of the depth of groundwater in national statistics also indicates the flow in the direction of the topographic slope. Finally, a clay layer with a thickness of 10 to 30 meters was observed in the drilling log of the piezometers in the south and southwest of the aquifer. Examining all the results shows that the existing aquifer is probably a double-layered aquifer, where the flow direction in the upper layer is in the direction of the topographic slope and in the lower layer is against it, and the piezometers of the south and southwest parts penetrated the lower aquifer. In order to confirm the desired hypothesis, it is suggested to carry out geophysical studies in the area or to dig exploratory wells.
