Amin Ahmadi, Manouchehr Chitsazan , Seyed Yahya Mirzaee , Arash Nadri ,
Volume 16, Issue 2 (9-2022)
Abstract
In order to protect water wells, it is necessary to analyze the zones of influence, capture, recharge and discharge zones. Despite much research, this issue still needs further discussion. The purpose of this research is to analyze the capture and discharge zones of water wells in alluvial unconfined aquifers. For this purpose, a hypothetical aquifer was simulated using the Modflow and Modpath models. The accuracy of the numerical model outputs was confirmed by comparison with the analytical calculations, and then the effect of the independent parameters of the well and the aquifer was investigated. This research showed that, contrary to popular belief, changes in hydraulic conductivity, specific yield, bedrock dip, initial thickness, porosity, and heterogeneity do not cause changes in the surface extent of the well's capture zone in the unconfined aquifer.This research has shown that changes in surface recharge, discharge and well location cause many changes in the surface extent of the well capture zone in unconfined alluvial aquifers. Investigation of the effect of pumping time in a single well system showed that the size of the capture zone initially increases, but after a short period, of time, despite the continued expansion of the drawdown cone, its position stabilises. It was found that the change in all the above parameters causes a change in the size of the well's discharge zone. The stability of the above-mentioned areas is very important for the determination of zones for the protection of the quantity and quality of water wells! It has been found that the relative stability of the water level in the aquifer at an appropriate level is necessary, and this requires the management of the aquifer and the allocation of a limited percentage of the aquifer recharge to discharge through wells.
Miss Masoumeh Nikbakht, Prof Mohammad Nakhaei, Prof Ata Shakeri, Dr Vahab Amiri,
Volume 16, Issue 4 (12-2022)
Abstract
In this study, the hydrogeochemical and qualitative status of groundwater resources of the Zarabad coastal aquifer in southeast Iran has been investigated. The decreasing order of cations and anions is Na+>Ca2+>Mg2+>K+ and Cl->SO42->HCO3-, respectively. The two most water type are Na-Cl (78%) and Ca-Mg-Cl (22%). The water type, chlorine-alkalinity index, ion ratios, and position of the samples on the Gibbs diagram show that cation exchange (direct and reverse), weathering of silicates and evaporites, and seawater intrusion are the main controlling processes of water chemistry. The ionic ratios of SO42-/Cl-, B/Cl-, and Na+/Cl- indicate that saltwater infiltration increases as the distance from the Rabach River increases, particularly in the northwest and southeast regions. This can lead to a decrease in the quality of water resources. Moreover, the water quality for agricultural use is assessed based on some indices, including electrical conductivity (EC), sodium percentage (Na%), sodium absorption ratio (SAR), residual sodium carbonate (RSC), magnesium absorption ratio (MAR), permeability index (PI), Kelly’s ratio (KR), and USSL and Wilcox diagrams. The results showed that about 60% of the samples had unsuitable quality for irrigation. These samples were located in the northwestern and southeastern parts of the plain. About 40% of the samples have suitable quality for irrigation and are located in the vicinity of the Rabach River.
Khadijeh Kord, Heeva Elmizadeh, Hakimeh Amanipour,
Volume 17, Issue 1 (3-2023)
Abstract
The study area is a part of the Dez River Basin, which is located in the central part of the basin. In this area, due to the climatic conditions, the irregular availability in terms of time and space, the increasing use of water resources and surface water resources, there is a great dependence on the underground water of the region. The main objective of this research is to investigate the factors influencing the fluctuations of the water level in the Dezful-Andimeshk plain during a statistical period of 20 years. For this purpose, using piezometric well level data and well logs of the study area in WinLog software, maps of the groundwater level and the bottom level of reservoir were prepared using theIDW method. The results of the research showed that the greatest drawdown occurred in north-eastern, south-eastern and western parts of the study area. Asthe amount of precipitation, evaporation and temperature are high in this part, one of the reasons for the decline in these parts can be attributed to the climatic factors of the region. Other factors in the decline of the reservoir level are the main river channel and the high slope of the area. Comparing the changes in the reservoir level with the flow of the Dez River showed that there is a high correlation between the changes in these two parameters with a time interval of one year. Therefore, according to agricultural activities, these limited resources should be harvested, scientifically and fundamentally, the region will be at risk of a serious water crisis in the future.
Dr Seyed Yahya Mirzaee, Phd Student Zahra Chaghazardi, Dr Manouchehr Chitsazan, Dr Farshad Alijani,
Volume 17, Issue 1 (3-2023)
Abstract
The Evan plain is located in the Khuzestan province in the southwest of Andimshek city. Groundwater is one of the available water resources for irrigation, drinking, and industry in this region. Due to the importance of examining the ground water quality of the Evan plain, hydrochemical parameters and nitrate pollution have been evaluated. Nitrate is one of the most widespread pollutants of ground water in the world. However, few studies have been conducted on this pollutant in the Evan plain. Therefore, to assess the quality of ground water in this area with emphasis on nitrate pollution, sampling was carried out in September of the water year (1400-1401) from 22 wells in this plain. During the sampling, field parameters (temperature, pH, EC), concentrations of major elements (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO32-, CO32-), and nitrate were measured. The results of the factor analysis demonstrated three influencing factors, namely EC, Na+, K+, Mg2+, Ca2+, Cl-, SO42- (as the first factor), pH and Hco32- (as the second factor), and NO3- (as the third factor), with a total of 89.72% having the most changes in the Evan plain aquifer. The dominant water type in the Evan plain is sulfate-calcite. Hierarchical clustering analysis shows the three clusters for the regionalization of nitrate data. In general, the changes in nitrate ion concentration in the groundwater of the Evan plain are affected by the size of the soil particles, the depth of the groundwater, and the utilization of chemical fertilizers in the area.
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.
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.
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.
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.
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.
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.
Amin Ahmadi, Maryam Zebarjad, Ghoramreza Mirzavand,
Volume 18, Issue 1 (5-2024)
Abstract
The zone of influence is the area where water withdrawal from the well causes the water level to fall. The drawdown cone is a conical shape of the water level in the zone of influence, and it is necessary to know the effect of the factors influencing it. Previous studies have mainly investigated aquifers with horizontal water levels and less realistic conditions. The purpose of this study is to investigate the effect of well physical parameters on the drawdown cone in one of the unconfined aquifers with a sloping water surface. In this aquifer, a normal discharge well was simulated using the Modflow program and the effect of the target parameters was studied. The results showed that: the drawdown cone is symmetrical up to long pumping and relatively long distances; the zone of influence will eventually extend to the entire aquifer and significant drawdown will occur at long distances. A significant part of the drawdown in the well is recovered in the first moments of pump shutdown, but at long distances, the drawdown continues to increase for a long time. An inflection point can be extracted from the drawdown cone which represents the minimum drawdown that does not increase after the pump is stopped and can be introduced as a unique value. By increasing the flow several times, the depth of the cone increases, but the width of the cone increases only slightly. If the pump is turned on and off successively, the general shape of the cone does not depend on the nominal discharge of the well, but mainly on the average discharge of the aquifer. Relative infiltration increases the depth of the cone only near the well and has no significant effect on its shape further away.
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.
