Showing 45 results for Arm
K. Enayati, M.j. Rousta, A. Vakili,
Volume 15, Issue 56 (7-2011)
Abstract
Soil structure and aggregate stability affect soil erodibility. There is a necessity for increasing aggregate stability against erosive factors such as wind and water. This study was conducted on surface soil samples (0-20cm) collected from agricultural land susceptible to erosion located in Chahoo, southeast of Fars province. The experimental design was CRD with 10 treatments and was replicated 3 times as follows: control plot (without addition of soil amendments), pure gypsum, chopped wheat straw, farm yard manure, gypsum+wheat straw, gypsum+ farm yard manure (1% w/w), cement at levels (0.3% w/w), (0.6% w/w), (0.9% w/w), gypsum +cement (0.9% w/w). After one, four and seven months, the amounts of soil aggregates in 53-4000 µm sizes were determined by wet sieving and MWD was calculated. The results of aggregate size distribution in every stage of the experiment showed that application of farm yard manure and wheat straw separately or in combination with gypsum through reduction in aggregates with diameters of <106 µm has caused an increase in aggregates with diameter of >106 µm. Based on the results of this research, the effect of these treatments, which increased MWD of the aggregate, results from the amount of aggregates with diameters larger than 1000 µm. According to the results of this study, it is suggested that these treatments be considered suitable to increase the stability of sensitive silt loam soils.
H. Kedri Gharibvand, G. A. Dianati Tilaki, P. Tahmasebi, M. Mesdaghi, M. Sardari,
Volume 17, Issue 64 (9-2013)
Abstract
The aim of this research was to determine the effects of Camphorosma monspeliaca species on soil variables in its habitat. Ecological positive or negative effects of new species on environment must carefully be examined before allowing their plantation in vast areas on the other hand these species with their special characteristics have special effects on their surrounding environment that should be considered. Camphorosma monspeliaca is one of the non-native and adapted species in Chaharmahal va Bakhtiari Province that its unique habitat has 3500 ha area. Effect of this species on new environment requires more studies on their several different aspects. Here we studied effect of this species on soil in order to assess ecological effects of this species on environment. This species distributed in all of the landscape but most distribution of species located at southern and northern aspects and land with flat topography.This species can establish in non saline soil, loam and clay loam texture with different value of organic matter, lime and gypsum. The research was carried out at four stages of information and background collection, field sampling, soil test and statistics analysis. The research method was based on comparison among adjacent stand and stands of this species. Soil variables in two surface (0-10 cm) and depth (10-30 cm) were measured. Result showed that there was significant difference among adjacent stand and stands of this species in terms of SAR, OM and Sand in stands of this species were greater than the adjacent stands. This species increased content of organic matter and amounts of SAR, OM and Sand. From the results obtained on three topography position, despite of negative effect of Camphorosma monspeliaca on under soil with increase of SAR, it can be concluded that Camphorosma monspeliaca had a positive effect on soil organic matter and soil texture
J. Hamzei, M. Seyedi,
Volume 18, Issue 70 (3-2015)
Abstract
This experiment was carried out at the Agricultural Research Station of Bu-Ali Sina University to study the effect of different tillage methods on bulk density, yield, and yield components of barley (Hordeum vulgare) cultivars under rainfed conditions. Three levels of tillage (CT: conventional tillage, MT: minimum tillage and NT: no tillage) and five barely cultivars (V1: Local V2: AbidarV3: Valfagr V4: Bahman and V5: Makouei) were evaluated in a factorial arrangement in a completely randomized block design with three replications in the growing season of 2010-11. Traits of bulk density plant height, grain yield, yield components, biological yield, and harvest index (HI) were evaluated. The results showed that maximum value of bulk density (1.09, 1.26 and 1.29 g cm-3 for 0-10, 10-20 and 20-30 cm of sampling depth, respectively) was observed at MT treatment. But, there was no significant difference between MT and NT treatments for this trait. In comparison of cultivars, maximum bulk density was achieved with Valfagr cultivar. Using chisel plow (MT treatment) produced maximum plant height (70 cm) and yield components (513 numbers of spike m-2 and 19.2 grain spik-1). Also, among cultivars maximum plant height (72.7 cm) and grain number spike-1 (23.2 grain spike-1) belonged to Valfagr cultivar. Also, results showed that V3×MT treatment had the highest grain yield (3100 kg ha-1). Therefore, the findings of the study recommend using chisel plow (MT treatment) and Valfagr cultivar.
D. Rajabi, H. Karami, Kh. Hosseini, S. F. Mousavi , S. A. Hashemi,
Volume 19, Issue 73 (11-2015)
Abstract
Non-linear Muskingum model is an efficient method for flood routing. However, the efficiency of this method is influenced by three applied parameters. Therefore, efficiency assessment of Imperialist Competition Algorithm (ICA) to evaluate optimum parameters of non-linear Muskingum model was addressed in this study. In addition to ICA, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) were also used to find an available criterion to verify ICA. In this regard, ICA was applied for Wilson flood routing then, routing of two flood events of DoAab Samsami River was investigated. In case of Wilson flood, the target function was considered as the sum of squared deviation (SSQ) of observed and calculated dischargem. Routing two other floods, in addition to SSQ, another target function was also considered as the sum of absolute deviations of observed and calculated discharge. For the first floodwater based on SSQ, GA indicated the best performance however, ICA was in the first place, based on SAD. For the second floodwater, based on both target functions, ICA indicated a better operation. According to the obtained results, it can be said that ICA could be recommended as an appropriate method to evaluate the parameters of Muskingum non-linear model.
O. Mohammadrezapour, M. J. Zeynali,
Volume 22, Issue 1 (6-2018)
Abstract
One of the most important issues in the field of optimizing water resources management is the optimal utilization of the dam reservoirs. In the recent decades, the optimal operation of dams has been one of the most interesting issues considered by water resources planners in the country. Due to the complexities of the typical optimization methods, employing an evolutionary algorithm is regarded here. One of the most significant algorithms is the ant colony algorithm. So the aim of this study is to optimize the delivery of Golestan and Voshmgir reservoirs to meet the needs of the down lands using the elite ant colony algorithm, maximum – minimum ants, ranked ants, and particle swarm algorithms, and to compare the performance of these algorithms with each other. The considered decision variable was the release of the reservoirs in the above- mentioned dams. In this study, the data over a 5-year period, from 2006-2007 to 2011-2012, was used for modeling. The results showed that all algorithms could optimize the release amount optimally; however, the elite ant algorithm with the objective function value of 0.6407 estimated the release values with great accuracy in both dams. Also, the particle swarm algorithm with 1.275 of the objective function value was well-matched with the release values. The ranked ant algorithm with 18.924 and Max-Min ant with 26.431 of the objective function valuewere, respectively, at the next levels of performance optimization of the release values from Golestan and Voshgar dams.
S. F. Mousavi, H. R. Vaziri, H. Karami, O. Hadiani,
Volume 22, Issue 1 (6-2018)
Abstract
Exploitation of dam reservoirs is one of the major problems in the management of water resources. In this research, Crow Search Algorithm (CSA) was used for the first time to manage the operation of reservoirs. Also, the results related to the exploitation of the single-reservoir system of Shahid-Rajaei dam, located in Mazandaran province, northern Iran, which meets the downstream water demands, were compared to those obtained by applying the Particle Swarm and Genetic algorithms. Time reliability, volume reliability, vulnerability and reversibility indices, and a multi-criteria decision-making model were used to select the best algorithm. The results showed that the CSA obtained results close to the problem’s absolute optimal response, such that the average responses in the Crow, Particle Swarm and Genetic Algorithms were 99, 75 and 61 percent of the absolute optimal response, respectively. Besides, except for the time reliability index, the CSA had a better performance in the rest of the indices, as compared to Particle Swarm and Genetic Algorithms. The coefficient of variation of the obtained responses by CSA was 14 and 16 times smaller than the Genetic and Particle Swarm Algorithms, respectively. The multi-criteria decision-making model revealed that the CSA was ranked first, as compared to the other two algorithms, in the Shahid-Rajaei Reservoir's operation problem.
M. A. Geranmehr, M. R. Chamani, K. Asghari,
Volume 22, Issue 3 (11-2018)
Abstract
A water distribution network (WDN) may not be able to satisfy all required demands when it’s in the pressure deficit mode or under over-loaded demand conditions. Analysis of the network in this mode requires pressure dependent analysis (PDA). Unlike demand driven analysis (DDA), PDA needs an extra equation for every node to relate the nodal demand and the nodal pressure; so it should be solved with the other network’s equations simultaneously. In this paper, based on the Particle Swarm Optimization (PSO) algorithm, a decision support system has been developed by using MATLAB and EPANET for PDA simulation in WDNs. A four-loop network selected from the literature was analyzed using different scenarios and different pressure dependent functions presented by the previous investigations. The results showed that the proposed model (PSO-PDA) was as accurate as the previous ones and provided better convergence. The results of the nodes’ pressure and discharge also indicated minor differences obtained by different PDA functions. However, the differences between the results of PDA and DDA were considerable.
S. M. Seyedan, R. Bahramloo,
Volume 22, Issue 4 (12-2018)
Abstract
In recent years, with the excessive use of underground water resources in the Malayer Plain, the water level has dropped sharply and underground water resources, which serve as the main source of water supply for the agricultural sector and drinking, the city is facing a serious risk. Because of the relevance of each of the fields with other agricultural fields around, this study was done to show the potential effect of this problem on the welfare. So, in this study, the special econometric method was employed. The purpose of this study was to analyze the welfare of farmers and how it is affected by the exploitation of underground water resources. For this purpose, by using social welfare function, the effect of change in the value of groundwater level of social welfare producers was addressed. The necessary information was collected from 119 questionnaires carried out in 2015 .Moran's I statistics showed that the results of special regression method were better than those of Ols. The results of this study indicates a decline in the welfare loss of groundwater level and the continuation of the harvest of underground water resources would lead to a reduction in access to water and reduced production. The rate of change in return for the welfare of the reduction of every meter of underground water level to cultivate wheat and potatoes was 6983 and 7634 million Rials, respectively.
S. Chavoshi,
Volume 22, Issue 4 (12-2018)
Abstract
Regional flood frequency studies are initialized by the delineation of the homogeneous catchments. This study was based on "Region of Influence" concept, aiming to find the similar catchments in the south of Caspian Sea. The methodology utilized the Particle Swarm Optimization Algorithm, PSO, to optimize the fuzzy system over a dataset of catchment properties. The main catchment variables in relation to flood were determined by the principle component analysis method and employed as the inputs in the fuzzy system. Catchments grouping was performed over these fuzzy input variables by the iterative process. The optimum similar groups were obtained by PSO, and the heterogeneous L-moment index was used as the termination criterion for the optimization process. A total of 61 hydrometric stations located in the study area were selected and their relevant catchments' physical, climatic and hydrologic properties in relation to flood were studied. Principle Component Analysis by Variomax Rotation Factor over the catchments datasets tended to four out of 16 physical variables, including area, mean elevation, Gravelious Factor and Form Factor, as the main parameters in terms of homogeneity with 84 percent of accumulative variance. These variables, as well as mean annual rainfall, were used as the input data to define the fuzzy system. PSO algorithm was then employed to optimize the developed fuzzy system. The developed algorithm tended to yield the best result in the 9th iteration with 26 and 22 for the minimum average and the optimum values of cost function, respectively. The topology of the resulting algorithm included inertia weight, local and acceleration rates, the number of generations and population size, with the values of 0.7298, 1.4962, 1.4962, 10 and 5, respectively. This study tended to a total of 61 regions of influence, proportional to the relevant 61 sites. According to the geographical location of the catchments in the region, it could be concluded that the geographical proximity doesn't necessarily involve homogeneity. The obtained results indicated the efficient potential of PSO-FES in the delineation of the homogenous catchments in the study area.
H. Ghamarnia, Z. Jalili, D. Kahrizy,
Volume 23, Issue 3 (12-2019)
Abstract
Exactly estimating of water requirement is essential for water balance studies, design and management of irrigation systems and water resources management. Because of limited soil and water resources in Iran, for optimal use of water resources in the agricultural sector, it is necessary to determine the amount of water requirement by different plants in different climatological conditions. In order to determine the water requirement and crop coefficients of Stevia, six lysimeter numbers were used in three replications for stevia and reference plant (grass). The reference Stevia plant evapotranspiration was measured on a daily basis. The results showed that during the 537 day period of Stevia cultivation, the maximum and minimum water requirement in the first and second year of cultivation was respectively 9.85 and 1.69 mm per day, and for the reference plant was obtained as 6.54 and 1.84 mm per day. In this study, the Kc coefficients in initial, development, intermediate and final stages of growth in 2016 were 0.76, 1.11, 1.46 and 1.05 and in 2017 at growth stages, were 0.76, 1.18, 1.52 and 1.29 respectively. The average of individual Stevia plant growth factors for four growth stages in two years of research was obtained as 0.76, 1.15, 1.49, and 1.17, respectively.
S. Mirbagheri, M. Naderi, M. H. Salehi, J. Mohammadi,
Volume 23, Issue 3 (12-2019)
Abstract
Rivers are one of the most important source of water supply for drinking and farming purposes. Zard River is one of the surface water resources of Khuzestan province. The purpose of this study is to evaluate the quality of the river water and to observe the trend of changes in the water quality of this river in the Mashin station during the period of 1997-2015 by using the Man-Kendal, Spearman, variance analysis statistical methods and the least significant difference (LSD) and cluster analysis. LSD test shows SAR, Na, Cl, pH parameters up to 2010 (before Jare dam construction) were significant at 95% confidence level compared to 2015 (year of control). No changes were made after dam construction. According to Mann-Kendal non-parametric test, pH, Ca and SO4 have a significant upward trend to the 0.037, 0.393 and 0.376 respectively, the variables Cl, SAR, Na and temperature have a significant decreasing trend to the -0.387, -0.417, -0.386 and -0.1 respectively. Also Spearman test shows that the dam improved the quality of river water regarding to salinity. Variance analysis show that pH, SAR, Na, Cl, Ca and SO4 have significant difference. Cluster analysis classified the qualitative data before the construction of the dam in three clusters and after the construction of the dam were divided into two clusters where TDS variable was less distant than other variables. As a result, the quality of the irrigation water is changed downward and the TDS is more similar to the other variables compared.
L. Neisi, P. Tishehzan,
Volume 23, Issue 3 (12-2019)
Abstract
Rivers are one of the most important source of water supply for drinking and farming purposes. Zard River is one of the surface water resources of Khuzestan province. The purpose of this study is to evaluate the quality of the river water and to observe the trend of changes in the water quality of this river in the Mashin station during the period of 1997-2015 by using the Man-Kendal, Spearman, variance analysis statistical methods and the least significant difference (LSD) and cluster analysis. LSD test shows SAR, Na, Cl, pH parameters up to 2010 (before Jare dam construction) were significant at 95% confidence level compared to 2015 (year of control). No changes were made after dam construction. According to Mann-Kendal non-parametric test, pH, Ca and SO4 have a significant upward trend to the 0.037, 0.393 and 0.376 respectively, the variables Cl, SAR, Na and temperature have a significant decreasing trend to the -0.387, -0.417, -0.386 and -0.1 respectively. Also Spearman test shows that the dam improved the quality of river water regarding to salinity. Variance analysis show that pH, SAR, Na, Cl, Ca and SO4 have significant difference. Cluster analysis classified the qualitative data before the construction of the dam in three clusters and after the construction of the dam were divided into two clusters where TDS variable was less distant than other variables. As a result, the quality of the irrigation water is changed downward and the TDS is more similar to the other variables compared.
M. H. Nasserzadeh, B. Alijani, M. Paydari,
Volume 24, Issue 2 (7-2020)
Abstract
Given the climatic changes and threats to food security in recent years, they have have become a major issue in agricultural climatology. The present study aimed to investigate the status of agricultural climate suitable for the cultivation of rice in the light of the influential climatic conditions in the past. Given the effect of temperature and the amount of precipitations on rice growth and the sensitivity of rice to these two variables, the study examined the predicted future temperature and rainfall and their effects on rice. Data related to the temperature and rainfalls were obtained from the Meteorological Organization. Additionally, the temperature and agricultural potential of the region were considered. By preparing the agricultural calendar for the cultivation of rice, the correlation between temperature, precipitation and rice productivity was calculated using the Spearman Correlation coefficient. By using the SDSM model, future data and temperature and precipitation return period were determined in the SMADA software. The results demonstrated that minimum spring temperature tended to be late spring. The minimum temperature had the highest impact in April, the maximum temperature had the highest impact in July and the maximum rainfall had the highest effect in both June and July. Based on the results of the prediction models, the studied region would experience an increase in temperature and rainfall by providing favorable conditions for the cultivation of rice. However, delays in the cold season and shortness of the growth period increased the risks associated with the cultivation of rice in this period.
F. Saniesales, S. Soltani, R. Modarres,
Volume 25, Issue 2 (9-2021)
Abstract
Several indices are used for drought identification and quantification. In this paper, the new Standardized Palmer Drought index (SPDI) was introduced and then the drought condition of Chaharmahal-Va-Bakhtiari Province was studied using this index. For this study, 11 synoptic, climatology, and evaporation meteorology stations were selected. Essential information in this investigation includes monthly temperature, monthly precipitation, and soil moisture measurement. To estimate SPDI, moisture departure, was first calculated on a monthly time scale. Then, converted to cumulative moisture departure values in different time scales including 3, 6, 9, 12, and 24 months. The best statistical distribution (GEV) was then fitted to cumulative departure. These values were then standardized to have the SPDI. The results showed that, as soil moisture affects SPDI estimation, it will be more valid for analyzing and monitoring drought conditions, especially for agricultural drought. Also, the results showed that 2000, 2001, and 2008 years were the driest time in this Province from 1988 to 2012. Moreover, drought frequency was found out in the western half of the Province more than in the other parts.
M. Motamedi, H. R. Eshghizadeh, A. Nematpour, A. Gohari, B. Safa,
Volume 25, Issue 2 (9-2021)
Abstract
World climate change is an accepted important subject but its negative effects are severe in arid and semi-arid areas of Iran. So, in the present study, two climate scenarios including RCP 8.5 (critical scenario) and RCP 4.5 (moderate scenario) during 2020, 2030, and 2040 decades and their effects on temperature changes in the wheat growth period in five cities of Isfahan province including Isfahan, Najaf Abad, Chadegan, Burkhar, and Meimeh have been investigated. The survey of temperature changes during wheat growth in the next decades showed that Burkhar, Isfahan, Najaf Abad, Chadegan, and Meimeh, respectively will experience more days with a temperature higher than 30°C in 2020, 2030, and 2040 decades than the mean of two recent years (2017-2018). Furthermore, in comparison with present conditions, the most changes in the number of days with a temperature higher than 30°C in next decades climates (2020, 2030, and 2040 decades) will be in Burkhar, Meimeh, Chadegan, Najaf Abad, and Isfahan, respectively. The range of changes percent in the number of days higher than 30°C in next climate conditions rather than present condition will be varied between 5 percent (Isfahan) till 97 percent (Burkhar). The changes percent in all studied cities were more in RCP 8.5 than RCP 4.5. During wheat growth, the number of days less than zero°C will be less in Isfahan, Burkhar, and Meimeh while will be more in Najaf Abad and Chadegan. The evaporation- transpiration will be increased in the next decades during wheat growth. As a result, planning and using compatibility strategies for each city is important to guarantee wheat production.
M. Hayatzadeh, M. Eshghizadeh, V. ,
Volume 26, Issue 4 (12-2022)
Abstract
The land use change as well as changes in climatic parameters such as temperature increase affect many natural processes such as soil erosion and sediment production, floods, and degradation of physical and chemical properties of soil. Therefore, it is necessary to pay attention to different aspects of the effect of these changes in studies and macro decisions of the country. In the present study, the SWAT conceptual model was used to test and analyze the existing scenarios in the Marvast basin. After calibrating the model, the two scenarios were tested. The first scenario is in the field of agricultural management and conversion of gardens to agricultural lands and the second scenario is a 0.5-degree increase in temperature by assuming other conditions are constant. The calibration and validation results of the model with the Nash-Sutcliffe test showed 0.66 and 0.68 respectively, which indicate the acceptable performance of the model in the study area. Then, the results of using two scenarios of land use change and heating, especially in recent years showed the effect of 30 percent of the climate scenario on the increase of flooding in the basin. The scenario of changing the use of garden lands to agriculture in two cases of 20% and 50% change of use of 10% and 12% was added to the flooding of the basin. The results indicate that in similar areas of the study area which is located in a dry climate zone, a possible increase in temperature can have a significant effect on flooding in the basin. However, the indirect impact of the human factor in increasing greenhouse gases and flooding in the basin should not be ignored.
S. Esmailian, M. Pajouhesh, N. Gharahi, Kh. Abdollahi, Gh. Shams,
Volume 28, Issue 2 (8-2024)
Abstract
Studying the process of soil erosion and evaluating its effective factors is one of the most important prerequisites for proper management of soil and water resources. This study was conducted to investigate the production of surface and pipe runoff and sediment using artificial rainfall on silt loam soil in the laboratory. So, the soil was collected from the study area and transported to the laboratory. Laboratory experiments were performed on a soil bed in a rectangular flume with three pipes, at slopes of 2%, 6%, 10%, 14%, and 18% under simulated rain (30 mm/h) for one hour. Related graphs were drawn in Excel to analyze the results, and Spearman's correlation test was used in SPSS software to check the correlation between runoff and sediment values in each slope. The results showed that with the increase in slope, the sum of surface and pipe runoff and sediment increased over time. For example, in a slope of 2%, the runoff and sediment in the initial moments of the experiment increased from 0 to 1.3 liters and 26.2 g m-2 at the end of the experiment. Also, the correlation coefficient between runoff and sediment in the slopes was 0.98, 0.62, 0.4, 0.93, and 0.15, respectively, which was significant in some, but in others, it was not significant because of soil loss.
A.r Vaezi, Kh. Sahandi, F. Haghshenas,
Volume 28, Issue 3 (10-2024)
Abstract
Water erosion can be affected by land use change and soil degradation by agricultural activities. This study was conducted to investigate the effects of land use change in poor pastures on soil physical degradation and water erosion in semi-arid regions. Experiments were performed in 42 soil samples taken from seven areas covering the two land uses: poor pasture and rainfed agriculture, which have different soil textures (clay loam, silty clay loam, sandy clay loam, silt loam, loam, sandy loam, and sandy loam). The physical characteristics of soils were measured in the samples of both types of land use and its changes were expressed as physical degradation of the soil. The soil's susceptibility to water erosion was measured under simulated rainfall with 50 mm h-1 intensity for 60 min. The results showed that the land use change in pastures leads to the physical deterioration of soils; so bulk density, porosity, macropore, field capacity, saturated point, aggregate size, and aggregate stability were degraded with a rate of 28, 22, 41, 11, 5, 62, and 63 percentages. The structural characteristics of soil (aggregate size and stability) had the highest physical deterioration due to the land use change in the pastures. The change in land use change greatly increased the sensitivity of soils to water erosion. A significant relationship was found between the susceptibility of water erosion and the soil's physical degradation. The soils with coarser and more stable aggregates have higher physical degradation by the land use change and in consequence show more susceptibility to water erosion.
B. Naderi-Samani, M. Ghobadinia1, B. Haghighati, S.m.r. Hosseini-Vardanjani, A.r. Ahmadpour-Samani,
Volume 29, Issue 1 (4-2025)
Abstract
Awareness of the impact of water deficit stress on the quantitative and qualitative performance of agricultural products, considering the recent recurrent droughts and reduced precipitation, is essential for water consumption management. This study aimed to evaluate the effects of different irrigation deficit treatments on the yield, yield components, and water use efficiency of autumn wheat in the Shahrekord region. An experiment with three replications was conducted in a completely randomized block design at the Agricultural and Natural Resources Research Center of Chaharmahal Va Bakhtiari Province during 2023-2024. The experimental treatments included four irrigation levels: full irrigation (T100), 80% of full irrigation (T80), 60% of full irrigation (T60), and 40% of full irrigation (T40). The application of the T60 deficit irrigation treatment resulted in a reduction of more than 14% in grain yield, while the T80 treatment caused a more than 31% decrease in grain yield. Additionally, the T60 treatment exhibited the highest water use efficiency at 1.22 kg per cubic meter, while the water use efficiency for the T100, T80, and T40 treatments was 1.06, 1.12, and 1.19 kg per cubic meter, respectively. The results showed that water deficit irrigation significantly affected the grain yield, biomass, and water use efficiency of autumn wheat under the climatic conditions of the Shahrekord region. The results of this study indicated that the T80 deficit irrigation treatment could have a more acceptable performance in terms of water efficiency.
M. Golestani, S. F. Mousavi, H. Karami,
Volume 29, Issue 3 (10-2025)
Abstract
Groundwater is a vital resource for meeting drinking, agricultural, and industrial needs in arid and semi-arid regions of Iran. In this study, quantitative and qualitative changes in groundwater in the Garmsar Plain were modeled using GIS, MODFLOW, and MT3DMS software during the period 2011-2013. Spatial and climatic data were comprehensively processed and prepared in the GIS environment, and groundwater flow was simulated using the MODFLOW model, and water quality changes were analyzed using the MT3DMS model. After validation with field data from 2012 to 2013, the model showed acceptable accuracy with statistical indicators of mean absolute error (MAE) in the range of 0.4 to 0.5 meters and root mean square error (RMSE) between 0.5 and 0.6 meters. The modeling results showed that a 15% increase in water withdrawal led to a decrease in the water table of up to 8 meters, a constant withdrawal led to a decrease of 7 meters, and a 15% decrease in withdrawal led to a decrease of 5 meters in the water table. From a quality perspective, the decrease in withdrawal improved the quality of irrigation water but increased the concentration of some pollutants, which requires the development of effective management strategies to protect groundwater resources. The findings of this study illustrate the importance of sustainable exploitation and smart management of groundwater resources in the Garmsar Plain.
