فهرست مطالب manouchehr chitsazan

Groundwater is the main source of drinking water in the northern Dezful-Andimeshk plain, Iran which has become saline in some cases. To check the drinking quality of groundwater, in October 2019, 16 samples were taken from different parts of the plain. The samples were analyzed for the concentration of major cations, anions, and nitrates.Two methods were used to evaluate water quality: the Schoeller deterministic method and the Fuzzy logic. The Schoeller method categorized water quality from good to bad and determined that 56.81, 20.83, 18.77, and 3.57% of the area had good, acceptable, inappropriate, and bad water quality, respectively. On the other hand, the Fuzzy method showed that 21.60% of the area had desirable groundwater with a confidence level of 70-81, 75.23% had acceptable water quality with a confidence level of 32-70, and 3.69% had non-acceptable quality with a confidence level of 20-22%. The Fuzzy method was found to be better in evaluating water quality as it provided a more comprehensive, accurate, and efficient assessment by covering uncertainties better.

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.

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.

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.

Subsidence is affectedby several factors, the most important and most common of which is excessive groundwater extraction from alluvial aquifers and, conversely, reduced aquifer recharging.Subsidence of the Damaneh-Daran plain, like many of the country's plains has recently expanded.The alluvial aquifer of the plain is unconfined, but part of it operates confined due to lithological diversity and has the potential for subsidence.In this regard, in this paper,first the subsidence rate inthe aquifer was determined by radar interferometer method and the results showed that the subsidence is almost spread in most of the southeastern part of the plain and its maximum is about 6.38 cm.In order to correlate the drop in water level in the aquifer with land subsidence, the aquifer model was prepared by finite difference method, which indicates an alluvial aquifer tank deficit of 33.8 million cubic meters. Prediction of groundwater level due to50% reduction of pumpingfrom the aquifer compared to current pumps showed thatthe predicted water level shows a correlation of more than70% in thesoutheastern part of the aquiferwhere similar conditions of the aquifer are confined with subsidence and indicates its significant effect on reducing subsidence in the aquifer.The results of this study show that oneof the most important proposed solutions to control the current state is to reduce the exploitation of groundwaterresources at least 50%, which can be important bymodifying the licenses of wellsand then closely monitoring the allowable abstraction. It can be done through the installation of smart meters and the optimaluse of water inthe agricultural sector.

The phenomenon of land subsidence, which is affected by human activities and various geological and hydrogeological parameters, is occurring in different parts of Iran. Land subsidence susceptibility mapping is a necessary prerequisite for land subsidence management. Proper assessment of land subsidence requires the determination of parameters affecting land subsidence to discover the spatial relationships between them and land subsidence. For this purpose, first, according to the land site subsidence, eight parameters affecting the subsidence in the Damaneh-Daran plain, two models were prepared. In the first model, eight parameters including annual groundwater level drawdown, aquifer medium, land use, pumping volume, aquifer thickness, net charge, distance from fault and topography called WALPSRFT based on weighting parameters and the second model based on optimization and compatibility of eight effective layers in subsidence, Was prepared by AHP-Fuzzy2 method and the final map of land subsidence vulnerability was obtained by combining layers in ArcGIS. Radar images and a Radar Interferometer (InSAR) were used to validate the models. The results show that both maps show a good correlation with radar data, and the map prepared by the hierarchical-fuzzy method shows the highest correlation with real radar data and subsidence in the plain. It separates in more detail on the whole surface of the plain. According to this model, most areas of the plain, especially the eastern part, are subject to subsidence, and management programs should be considered to control subsidence.

The faults and fractures play crucial roles in conducting groundwater flow and providing high recharge zones for aquifers. The hard rock formations are exposed on the ground surface of the west of Yazd Province in Iran and build a reliable groundwater source for consumption. This study aims to provide a hydro-tectonic conceptual model of the region using remote sensing techniques and GIS. The geological map, groundwater resource data, geophysical reports, hydrogeological reports, and Landsat ETM satellite images are collected and evaluated by field visits. The lineaments densities of the area have been extracted and projected on various maps. The results demonstrate that the likelihood of groundwater flow is correlated positively with the region's main geological structures and groundwater resource availability. Finally, to conclude, the hydrotectonics model of the area consists of several distinctive and non-distinctive aquifers because of the presence of hydrogeological and tectonic barriers, water-conducting passages, and even neutral fractures.

The faults and fractures play crucial roles in conducting groundwater flow and providing high recharge zones for aquifers. The hard rock formations are exposed on the ground surface of the west of Yazd Province in Iran and build a reliable groundwater source for consumption. This study aims to provide a hydro-tectonic conceptual model of the region using remote sensing techniques and GIS. The geological map, groundwater resource data, geophysical reports, hydrogeological reports, and Landsat ETM satellite images are collected and evaluated by field visits. The lineaments densities of the area have been extracted and projected on various maps. The results demonstrate that the likelihood of groundwater flow is correlated positively with the region's main geological structures and groundwater resource availability. Finally, to conclude, the hydrotectonics model of the area consists of several distinctive and non-distinctive aquifers because of the presence of hydrogeological and tectonic barriers, water-conducting passages, and even neutral fractures.

Alluvial rivers interact mostly with underlying groundwater bodies. These interactions that varies spatially and temporally, have recently received more attentions. This paper aims to evaluate the interaction between groundwater and surface water along the Dez river in the north part of the Dezful-Andimeshk district through developing a numerical simulation. For this purpose, the groundwater flow and river- groundwater interaction were simulated using a mathematical model in MODFLOW/GMS environment. The WetSpass model was used to estimate the groundwater recharge. The cluster analysis method, also, was utilized to identify the different zones of aquifer hydraulic characteristics. The results show that the Dez river has a losing connected nature and recharges groundwater. The river recharge to the aquifer was about 12 MCM during the 2013 and 2014. This recharge varies spatially and temporally and its maximum amount occurs during the 2014 March to June. Furthermore, the recharge rate was affected by the water release pattern from the Dez dam and topographic characteristics of the riverbed sediments. So that the maximum water exchanges occur in areas near the Chamgolak town and Dezful city with an average rate of 3.2 MCM per year.

Sulfur springs are distinguished from other groundwater sources by their specific therapeutic, thermal and hydrochemical properties. Golgir, Meydavood, Naft Sefid, pole Zal, Grasab JaOrdo, Mashrageh, Grab Behbahan, and Baba Ahmad Springs are low-temperature sulfur springs in Zagros area of Khuzestan. These springs have temperatures between 22 and 35 °C and appear along with the Zagros thrust. By analyzing the hydrochemical data of sulfur springs on two periods (December 2017 and May 2018) and applying the hydrochemical methods, principal component analysis (PCA) and hierarchical clustering (AHC), it has been tried to identify the factors affecting the chemical quality of the springs. The first factor includes the electrical conductivity, Na, Cl, K, Ca, Mg, As and Cd variables, this factor is due to the interaction of aquifer and water materials, as well as high correlation between the main ions, arsenic and cadmium indicates that these elements have similar origin.The second factor includes the SO4, NO3, and S variables. According to the results of TOC analysis, this factor can be attributed to the influence of oil brines. Piper diagrams and hierarchical Q-mode clustering were used to classify the springs studied. The Piper diagram separated these springs into three groups and the hierarchical Q-mode clustering method, taking into account further parameters of sulfur springs in four groups.

In the last decade, the management of karst water resources has been considered because of its particular role in supplying potable water. In this regard, this research studies the hydrochemical characteristics of springs located at the Ķīno anticline. The purpose of this research is to determine the hydraulic relationship and effective factors on the chemical quality of the springs by applying the hydrochemical data and using the main component analysis and hierarchical cluster analysis methods. The results of the analysis of the main components method show that the two components have the most impact on the chemical quality of springs. The first factor consists of magnesium, bicarbonate, sodium, chlorine, Total Dissolved Solids, and electrical conductivity, which is influenced by the quality characteristics of Absard and Mourei springs. The second factor is calcium ions, sulfate, which play the most role in the chemical quality of Susan and Tangsard springs. To investigate the hydraulic connection of the springs, the hierarchical cluster analysis method was used in “Q-mode” mode. According to the results of this analysis, the data of the Ķīno anticline springs are split into two major clusters, which indicate the hydraulic connection between these springs in each cluster. The results of cluster analysis in “R-mode” mode are also validated by the Q-mode method. The Piper diagram and ion ratios were used to study the chemical processes in the springs. The results of this study showed that the S1 spring with S2 and the S3 spring with S4 have a hydraulic connection.

Excessive population growth over the past three decades, limited surface water resources, agricultural, industrial, urban activities and excessive exploitation of aquifers have caused irreparable damage to Iran''s water resources regarding quality and quantity. To prevent the continuation of quantitative and qualitative decline, management of exploitation and protection of groundwater should be the basis of planning in the country. Groundwater management requires an adequate understanding of the aquifer system and the use of a tool that can simulate the response to the various quantitative and qualitative stresses of the aquifer in the current and future conditions. In this regard, by using the model, real conditions in nature can be simulated with good accuracy and achieved to acceptable results. The study area of Gamasiab is located in Sahne-Bisotun plain in the northeast of Kermanshah province. In this area, only one case investigated in a small part of the aquifer. In this study, the status of the aquifer and the relationship between surface and groundwater in the entire aquifer zone of Sahneh-Bistoon plain simulated with the use of the MODFLOW 2000 code, the GMS v10 software. The results of the model show that the water budget of Sahneh-Bisotun plain is negative in the year 88-87 and is 22.81 million cubic meters per year. The river is the main factor that recharges the aquifer, which is 248.8 million cubic meters per year, and pumping from water wells is the most crucial factor in the drainage of aquifers, which is 36.4 million cubic meters per year. The results of the model show that the Gamasiab River recharges the aquifer in two reaches and drains the aquifer in other reaches. The river drains 15.55 million cubic meters of water per year from the aquifer.

There are many springs in Iran that are contaminated by arsenic and therefore are not suitable for drinking purposes. Garu spring around Masjed Soleyman city is an indicator of such springs. In order to study the concentration of arsenic, 20 samples from spring and Asmari anticline observation wells were collected. Concentration of major and trace elements in the samples were measured. ICP-OES studies were carried out on 3 samples of the surrounding formation. The results showed that Garu spring has arsenic levels higher than 10ppb. Hydrochemical and statistical analyzes of water samples and sediment as well as significant correlation of arsenic with main cations, (i.e. Nickel and Vanadium) shows that anthropogenic factors do not have an effect on the amount of arsenic. It is found, that the origin of arsenic is geogenic (Gachsaran formation and oil brine influx). The mechanism of arsenic mobility during the wet season is the anaerobic respiration of Fe+3 reducing bacteria. Whereas, in the dry season, the environment is further reduced, as a result activity of the SRB and IRB in the span of springs leads to the reduction of iron by sulfide from sulfate respiration, this causes arsenic deposition. Also, gas chromatography analysis of the oil presented in spring shows that H2S is the result of thermochemical reduction of sulfate in carbonate reservoirs. According to the results of this study, the use of water resources in the region threatens the health of the inhabitants of the region, and arsenic removal methods should be used.

The water table fluctuation (WTF) method is based on rises of a water table are caused by recharging groundwater. To apply this method, an appropriate estimate of the specific yield in the zone of the groundwater level fluctuation is required. In this paper, the specific yield are estimated these methods include Drilling Well Logs (DWL), Envelope Straight Line (ESL) and Vertical Electrical Sounding (VES) method. To evaluate and choosing the best method, specific yields value by hydrologic and hydrogeological data during eight years (2006 to 2013) of Golgir plain with correlation coefficient between recharge-rainfall and recharge-baseflow in ESL method respectively was obtained r2=0.79 and r2=0.90. Also, attention to appropriate correlation coefficient in ESL method the specific yield optimized amount equal 0.12 for Golgir plain estimated. The coefficient correlation obtained from the relation between recharge groundwater value, base flow, and rainfall by using DWL, ESL and VES methods indicated that ESL method with r2=90 is the best method to estimate the specific yield. Hence, attention to importance of recharge value in planning and management of groundwater and high affection of specific yield value in WTF method, groundwater recharge estimation by using specific yield optimal value help to the water science researchers.

During recent years there has been increasing consciousness of, and concern about, groundwater water pollution and monitoring in Iran. In this context, a comprehensive review of the trace elements and heavy metals in groundwater of Oshtorinan Plain in northern part of Boroujerd has carried out to investigate the effects of weathering minerals, agricultural and industrial activities. Groundwater samples from ten wells, five qanats and a spring in both wet and dry seasons were collected and analyzed using a mass spectrometer (ICP_MS). Then, the results were compared with World Health Organization (WHO) standards. The measurement results show that from 63 elements measured, only the concentrations of Fe, Mg, Pb, Sr, V(0.4, 36.3, 62.9, 0.89 and 195.5 ppm, respectively) were above the permitted level. The amount of Pb, B and iron in groundwater samples in the study area indicates that concentrations of these elements from East and West are increasing toward the center. Also,increasing concentration of Sr. in the groundwater samples is mainly caused by processes such as the mineral weathering that occurs to igneous rocks, locating in the eastern parts of the plain. Engines wells in the area, abandoned wells, the steel alloy (in the northern entrance) pollution and mining activities are likely sources of potential pollution of heavy metals in groundwater and environmental threat to the region. Using principal component analysis, three main factors determine the quality of hydro chemical include the impact of major ions, trace elements and heavy metals, which collectively account for nearly 68% of the variance factors.

Land use change is a gradual process that entails dire consequences for groundwater quality and quantity. Quantitative changes in groundwater can be usually monitored by controlling the annual groundwater balance. Monitoring qualitative changes in groundwater, however, is both time-consuming and expensive. DRASTIC and SINTACS models exploit aquifer properties to predict its vulnerability. In this study, aquifer vulnerability assessment was performed by the DRASTIC & SINTACS models for future land use management in Khovayes, southwest Iran. The DRASTIC Model is based on hydrological and hydrogeological parameters involved in contaminant transport. SINTACS parameters are the same as those of the DRASTIC model, except that weighting and ranking the parameters are more flexible. Once vulnerability maps of the study region had been prepared, they were verified against the nitrate map. A correlation coefficient of 0.4 was obtained between the DRASTIC map and the nitrate one while the correlation between the SINTACS and the nitrate maps was found to be 0.8. Map removal and single-parameter sensitivity analyses were carried out, which showed the southwestern stretches of the study area as the region with the highest risk of vulnerability.

In this study، the impact of drought was investigated using climatological data of the Khorramdarre weather station in Abhar plain northwestern Iran during 1985/11 to 2012/10. The wet and drought years were specified using deciles index (DI). From a hyrdogeological viewpoint، the coincidence of dry period occurrence and decreasing trends of groundwater levels is strongly confirmed by the unit hydrograph of plain between 2007 and 2009. In order to assess the probability of drought occurrence، a Markov chain model was used to determine the intensity، duration and frequency of drought during 27 year period. The balance matrix، extracted from transition probability matrix، shows that the probability of drought events will be greater than occurrence of wet years on long term. The model predicts the probability of drought occurrence is 0. 19 per year and its duration will be 2. 1 years in the next 10 years. Except for dry conditions، which are likely to be followed by further dry conditions، the probability of transition from one climatological state to other is fairly random in successive periods. Results of such studies can be useful for drought risk estimation management، drought mitigation strategies، groundwater development plans and sustainable supply of water resources.

Protection of water resources, particularly groundwater resources is one of the most important issues in modern societies. On the other hand, the management of these resources plays an important role in stable development, and it requires accurate and comprehensive studies resources. In this study, comprehensive climatological, geological and hydrogeological (quantitative and qualitative) investigations were carried out to establish a hydrogeologal framework of Abhar Plain. Based on geophysical investigations, well log data and field survey, Abhar aquifer is an unconfined system and is mainly covered by recent alluvial deposits. The hydrogeological investigations showed that the aquifer is in danger by overdraft and negative water budget. On the contrary, the hydrochemical data are in an acceptable range for drinking and agricultural usages based on the available standards. The final results of this research can be useful for management strategies including aquifer development planning, groundwater modeling and determination of safe yield for water supply.

In this paper, the Artificial Neural Network (ANN) approach is applied for forecasting groundwater level fluctuation in Aghili plain, southwest Iran. An optimal design is completed for the two hidden layers with four different algorithms: gradient descent with momentum (GDM), levenberg marquardt (LM), resilient back propagation (RP), and scaled conjugate gradient (SCG). Rain, evaporation, relative humidity, temperature (maximum and minimum), discharge of irrigation canal, and groundwater recharge from the plain boundary were used in input layer while future groundwater level was used as output layer. Before training, the available data were divided into three groups, according to hydrogeological characteristics of different parts of the plain surrounding, each piezometer. Therefore, FFN-LM algorithm has shown best result in the present study for all three hydrogeological groups. At last, to evaluate applied division, a unit network with all data and using LM algorithm was trained. Validation of the network shows that dividing the piezometers into different groups of data and designing distinct networks gives more focus on simulating groundwater level in the plain. The degree of accuracy of the ANN model in prediction is acceptable. Thus, it can be determined that ANN provides a feasible method in predicting groundwater level in Aghili plain.