Iranian Water Research Journal

Abstract Introduction
In many parts of Iran, excessive groundwater extraction and insufficient recharge have caused significant decline in groundwater levels. The Shahrekord Plain watershed is among the regions experiencing groundwater depletion and negative water balance conditions. Managed Aquifer Recharge (MAR) is widely recognized as an effective approach for improving groundwater resources. Among MAR techniques, underground dams are particularly suitable for dry regions because they store water below the ground surface, reducing evaporation losses and enhancing groundwater availability. Unlike surface dams, underground dams intercept subsurface flow and increase groundwater storage within alluvial deposits upstream of the dam axis. These structures can improve water security, support agricultural production, and increase resilience to drought. The effectiveness of underground dams strongly depends on appropriate site selection. Hydrological, hydrogeological, geological, geomorphological, environmental, and socio-economic factors must all be considered during the planning process. Geographic Information Systems (GIS) have become valuable tools for integrating spatial datasets and supporting water-resource management decisions. GIS-based approaches enable the simultaneous evaluation of multiple criteria and facilitate the identification of suitable sites. Therefore, this study aimed to identify suitable underground dam axes within the Shahrekord Plain watershed using GIS-based spatial analysis as the first stage of a broader groundwater recharge planning framework.
Materials and Methods
This study was conducted in the Shahrekord Plain watershed, southwestern Iran, where increasing groundwater exploitation and recurrent droughts have intensified the need for sustainable groundwater management. A GIS-based spatial analysis framework was developed to identify suitable locations for underground dam construction. Spatial datasets, including digital elevation models (DEM), topographic maps, drainage networks, geological and hydrogeological maps, land-use data, and groundwater information, were integrated within the GIS environment. In the first stage, drainage channels were extracted and analyzed to identify narrow valley sections capable of intercepting subsurface flow with minimum construction cost. This process identified 51 potential underground dam axes. Subsequently, a series of exclusion criteria was applied to remove unsuitable locations. Areas with reservoir slopes greater than 5%, inappropriate land use (urban areas, exposed bedrock, and infrastructure), and unfavorable geological conditions were excluded. Geological investigations focused on identifying impermeable foundations and stable abutments while eliminating zones with fractured formations or high seepage potential. Environmental and socio-economic constraints were also incorporated by mapping qanat systems and defining protective buffer zones to avoid adverse impacts on existing groundwater resources. Finally, reservoir characteristics, including alluvial thickness, potential storage capacity, and groundwater recharge potential, were evaluated using borehole records and available geophysical data. The integration of these spatial criteria within a GIS framework provided a systematic and reproducible procedure for screening and selecting the most suitable underground dam locations in the study area.
Results and Discussion
The GIS-based screening procedure effectively reduced the number of potential underground dam locations by integrating topographic, geological, hydrogeological, environmental, and socio-economic criteria. From the initial 51 candidate axes identified along drainage channels, only 12 sites satisfied all selection requirements. Topographic analysis excluded areas with reservoir slopes exceeding 5%, while land-use evaluation eliminated urban areas, exposed bedrock, and incompatible land-cover classes. Geological investigations further reduced the candidate sites by removing locations with fractured bedrock, unfavorable lithology, or high seepage potential. Hydrogeological evaluation showed that thicker alluvial deposits and higher groundwater storage capacity significantly improved site suitability by increasing recharge potential and subsurface water storage. Incorporating qanat protection buffers ensured that selected sites would not cause adverse affect on traditional groundwater-dependentsystems or downstream water users, thereby improving the environmental and social sustainability of the proposed framework. The final 12 locations exhibited favorable reservoir geometry, suitable impermeable foundations, adequate alluvial thickness, low leakage risk, and minimal conflicts with existing infrastructure. These findings demonstrate that GIS-based multi-criteria evaluation provides a reliable and reproducible approach for identifying suitable underground dam sites while substantially reducing the need for costly field investigations. The results also confirm that successful underground dam planning requires the simultaneous consideration of hydrogeological, geological, environmental, and socio-economic factors rather than relying solely on engineering criteria. Overall, the proposed methodology offers an effective decision-support framework for sustainable groundwater management in semi-arid regions.
Conclusion
This study applied a GIS-based spatial analysis framework to identify suitable underground dam axes within the Shahrekord Plain watershed. By integrating topographic, geological, hydrogeological, land-use, environmental, and socio-economic criteria, the methodology successfully reduced 51 preliminary candidate sites to 12 suitable locations. The results confirm that GIS is a reliable and efficient tool for underground dam site selection and can significantly improve decision-making in groundwater recharge projects. Geological suitability, leakage potential, reservoir slope, alluvial thickness, and protection of existing qanat systems were identified as the most important factors influencing site suitability. The selected sites provide promising opportunities for enhancing groundwater storage, increasing drought resilience, and supporting sustainable water-resource management in the Shahrekord Plain watershed. As the first phase of a broader research program, this study establishes a foundation for future investigations involving multi-criteria ranking, engineering feasibility analysis, economic evaluation, and detailed hydrogeological modeling of the selected underground dam sites.

Abstract Extended Abstract
Introduction:
The Shahrekord plain faces chronic water scarcity, especially during dry seasons, and increasing dependence on groundwater resources to meet domestic, agricultural, and industrial demands. However, uncontrolled groundwater extraction has resulted in declining water tables and reduced aquifer sustainability, highlighting the urgent need for alternative water management strategies. Among the available solutions, subsurface dams have gained attention as an effective and environmentally friendly technique for controlling subsurface flow, enhancing groundwater recharge, and improving water storage capacity in alluvial aquifers. The successful implementation of subsurface dams critically depends on the proper selection of suitable locations, which requires a comprehensive evaluation of multiple hydrogeological, environmental, and socio-economic factors. Accordingly, the main objective of this study is to identify suitable sites and prioritize potential locations for subsurface dam construction within the Shahrekord Plain watershed using an integrated GIS and Multi-Criteria Decision-Making (MCDM) framework.

Materials and Methods
This research adopted a structured two-stage methodological framework. In the first stage, a GIS-based suitability analysis was conducted to identify potential locations suitable for subsurface dam construction. As a result of this process, 12 candidate dam axes were identified as suitable for further analysis. Detailed information regarding this stage is presented in the previous paper. In the second stage, the Analytical Hierarchy Process (AHP) was employed as the MCDM tool to prioritize the selected axes. The decision hierarchy was structured into main criteria, including groundwater quantity/quality, reservoir characteristics, axis conditions, and socio-economic factors, each further subdivided into relevant sub-criteria. Pairwise comparison matrices were developed based on expert judgment, field observations, and a literature review, and consistency ratios were checked to ensure the logical reliability of the comparisons. The weights of criteria were calculated using the geometric mean method. To address uncertainty and potential bias in expert weighting, five different decision scenarios were defined. In Scenario 1, all main criteria were assigned equal importance, representing a neutral decision perspective. In Scenarios 2 to 5, each scenario emphasized one dominant criterion by assigning it a higher relative weight compared to the other criteria, allowing for sensitivity analysis of the decision model. For each scenario, a composite suitability index was calculated for all 12 candidate axes by aggregating standardized criterion values using weighted linear combination methods. Hydrogeological parameters, surface runoff, recharge conditions, soil permeability, and socio-economic indicators were collected and analyzed.

Results and Discussion
The results of the multi-scenario AHP-GIS analysis revealed that although some variations occurred in rankings across different weighting scenarios, the overall prioritization pattern remained relatively stable, indicating the robustness of the decision model. Among the 12 candidate axes, Axis 54 consistently ranked as the most suitable site for subsurface dam construction in all scenarios. This high ranking was mainly attributed to its favorable hydrogeological and geomorphological characteristics, including relatively thick alluvial deposits, substantial subsurface flow availability, moderate slopes, and minimal environmental constraints. Furthermore, its limited negative impact on downstream water users strengthened its environmental and socio-economic acceptability. In contrast, Axis 65 consistently ranked as the least suitable option across all scenarios. The main limiting factors for this site included relatively steep topographic gradients, insufficient aquifer thickness, lower permeability of subsurface materials, and reduced groundwater storage capacity. Sensitivity analysis of the five scenarios indicated that groundwater quantity-related criteria had the greatest influence on site prioritization outcomes, followed by reservoir characteristics such as sediment thickness, permeability, and storage capacity. Socio-economic criteria, including accessibility, agricultural water demand, and proximity to settlements, also played a significant role in refining the final rankings. Water quality parameters were particularly important in excluding areas potentially affected by salinity sources, evaporitic formations, or anthropogenic contamination. The integration of GIS with AHP proved to be a powerful approach for managing complex spatial decision problems. The scenario-based approach further enhanced model reliability by demonstrating that the final ranking was not overly sensitive to minor changes in weighting assumptions.

Conclusion:
This study demonstrated that integrating GIS-based spatial analysis with the AHP provides an effective and reliable framework for identifying and prioritizing subsurface dam sites in complex hydrogeological environments. Applying this methodology in the Shahrekord watershed led to the identification of 12 suitable candidate axes and their evaluation under five different decision-making scenarios. The results consistently identified Axis 54 as the most suitable location, while Axis 65 was determined to be the least suitable due to its unfavorable structural and hydraulic characteristics. Overall, the findings indicated that hydrogeological parameters, particularly groundwater availability and aquifer storage characteristics, were the dominant factors influencing site suitability for subsurface dams. The proposed approach offers a transferable decision-support framework that can be applied to other arid and semi-arid regions.

Abstract Extended Abstract
Introduction:
Integrated Water Resources Management (IWRM) is defined by the Global Water Partnership (GWP) as “a process that promotes the coordinated development and management of water, land, and related resources to maximize economic and social welfare equitably without compromising the sustainability of vital ecosystems and the environment.” Recently, a physical index has been proposed to quantitatively evaluate water resource management by accounting for environmental water requirements. This index, based on the concepts of water accessibility and water supply, allows for a more integrated and comparative assessment of management performance. The Sefidrud watershed, covering an area of 58,452.84 km², is located in northwestern Iran. This study aims to: (a) assess the management levels of surface and groundwater resources across the Sefidrud watershed during the 1995–2017 observation period, and (b) examine the impacts of observed climate changes on water resource management levels during the study period.

Materials and Methods:
To evaluate and quantify the management levels of surface and groundwater resources in the Sefidrud watershed, SWAT hydrological model was employed. The watershed was delineated into 15 subbasins based on elevation, hydrometric, and dam data, and the model was run with inputs of soil, land-use, slope, and daily dam outflows. The model was implemented over the 1995–2017 period in two stages: a 16-year calibration period (1995–2010) and a 7-year validation period (2011–2017). Level of Management (LOM) for river water was estimated using a physical index that accounts for available water and total water supply. In this context, total water supply is defined as the volume of water withdrawn from the river. To calculate LOM, which denotes the management level of either river or groundwater resources, the available water volume (AW) of the river or groundwater and the water withdrawn from the river or groundwater for use in sectors (TWS ), were considered. The Environmental Flow Requirement (EFR) is also defined as a percentage of the river’s long-term annual mean flow. In this study, 80% of the river's long-term annual mean flow was allocated to EFR, and the remaining 20% to human needs and Accessible River Water (ARW). EFR for groundwater was determined based on the river’s baseflow contribution. River and groundwater management levels may vary from negative values up to +1, where negative values indicate mismanagement and positive values reflect acceptable management. The management levels of both river and groundwater resources during the observation period were computed under two scenarios: (1) the real scenario (reflecting actual climate and land-use conditions), and (2) the climate scenario (using daily precipitation and temperature data with trends removed, i.e., de-trended), and were subsequently compared.

Results and Discussions:
The performance evaluation of the SWAT model during the calibration period (1997–2010) indicated an acceptable level of accuracy in simulating monthly river flows at the subbasin scale. The coefficient of determination (R²) and the Nash–Sutcliffe Efficiency (NSE) exceeded 0.7 in most subbasins. To investigate the effect of precipitation changes, the annual mean precipitation derived from the observed time series was compared with the corresponding values from the detrended series. The impact of precipitation changes was estimated as the difference between the mean annual observed precipitation and the detrended values (observed minus detrended). Spatial analysis of the distribution of climate stations showed that decreasing precipitation trends predominantly occurred in the southwestern and eastern parts of the basin, whereas the central and northern regions experienced increases in annual precipitation during the period 1995–2017. Analysis of annual minimum and maximum temperature trends revealed that the entire study area experienced warming during 1995–2017, with the exception of the minimum temperature at the Tabriz station. The effect of climate change on river flow in each subbasin was determined by calculating the difference between simulated river flows under the actual scenario and those under the no-climate-change scenario (flow in actual scenario minus flow in no-climate-change scenario). Climate impact mapping showed that most subbasins experienced reductions in river flow due to decreased precipitation, although a few subbasins exhibited increases in flow associated with increased precipitation during 1995–2017. Because total water withdrawals in both the actual and no-climate-change scenarios remained constant, the observed changes in LOM values were attributable to variations in water availability. Consequently, climate change improved LOM in subbasins that experienced increased precipitation and river flow during the study period, whereas LOM declined in subbasins with decreased precipitation and flow. The impact of climate change on groundwater recharge in each subbasin was assessed by calculating the difference between simulated aquifer recharge under the actual scenario and that under the no-climate-change scenario (recharge in actual scenario minus recharge in no-climate-change scenario). Evaluation of climate change effects revealed that most subbasins experienced reductions in groundwater recharge due to decreased precipitation, whereas some subbasins showed slight increases in recharge rates as a result of higher precipitation during 1995–2017. The groundwater LOM declined in most of the study area because of reduced precipitation, although some areas exhibited increases.

Conclusion:
In this study, the impact of climate change on the Level of Management (LOM) of surface and groundwater resources was evaluated in the Sefidrud watershed, Iran, during the period 1995–2017. The watershed has experienced an increase in annual temperature; however, annual precipitation has been shown to increase or decrease depending on geographical location. The assessment of river and groundwater management levels indicated that the river management level in eight subbasins and the groundwater management level in three subbasins had negative values, indicating that water abstraction exceeded the volume of available water resources. Subbasins with negative management levels were recognised as ecological hotspots. Surface and groundwater resources respond to climate change in a coordinated manner. As precipitation is the main source of accessible water for both river and groundwater systems, long-term climatic trends continuously influence long-term water availability and management levels. In the evaluation of management levels of Sefidrud watershed, ecological hotspots were identified. These results can serve as a model for water resource decision-makers to propose management strategies adapted to local conditions. For example, in sustainable management approaches, special attention should be paid to areas where ecosystems dependent on water resources are stressed. To achieve an acceptable management level, appropriate strategies should be implemented such as reducing abstraction from surface and groundwater resources, improving irrigation efficiency, cultivating crops with lower water requirements, and enhancing agricultural land productivity.

Abstract Introduction:
Circular aquifers, such as those found in karst systems or fault-bounded basins, are common in nature and require precise modeling to understand their response to pumping. While extensive analytical solutions exist for rectangular, triangular, and semi-infinite aquifers, a comprehensive closed-form analytical solution for a finite circular aquifer with an arbitrarily located well has been notably absent. Previous studies have primarily focused on simpler geometries or relied on numerical approximations, leaving a gap in the direct analytical treatment of circular domains under pumping conditions. This study addresses this gap by developing a rigorous mathematical model capable of accurately predicting hydraulic head distribution and flow potential in a confined, homogeneous, and isotropic circular aquifer. The proposed solution eliminates the need for numerical discretization, offering a direct and computationally efficient tool for groundwater management in circular or near-circular aquifer systems.

Materials and Methods:
This study presents a rigorous closed-form analytical solution for modeling groundwater flow to a pumping well in a finite, homogeneous, isotropic, and confined circular aquifer. The aquifer has a fixed radius bb, and the well, with an infinitesimal radius, is positioned arbitrarily at coordinates (r0, θ0) with a constant pumping rate Q. The mathematical formulation begins with the governing partial differential equation in polar coordinates, which is the Poisson equation incorporating a point source term:

where ϕ (r, θ) is the hydraulic head, and the right-hand side uses the Dirac delta function δ to localize the source/sink. The physical constraints are enforced by two boundary conditions: (1) the head remains finite at the origin , and (2) the head is constant (set to zero) at the outer circular boundary ϕ(b,θ)=0.

The solution methodology employs the Green's function approach combined with a Fourier series expansion. First, the unknown potential is expanded into a full trigonometric series:
A similar expansion is applied to the source term. Substituting these series into the governing PDE decomposes the two-dimensional problem into an infinite set of one-dimensional ordinary differential equations for the radial coefficients ϕn(r).
The core of the solution is the construction of the Green's function G(r,θ;ρ,ψ) for the corresponding Dirichlet boundary-value problem on a circle. Due to different fundamental solutions, the cases for n=0 and n≥1 are treated separately. For n=0, the radial component is logarithmic:

For n≥1, the solution involves power laws:
The complete Green's function is then:

The final expression for the hydraulic head is obtained via convolution and simplifies, after applying the properties of the delta function, to a closed-form series solution:

This infinite series can be summed analytically using known identities, resulting in compact algebraic formulas valid in the regions r≤r0 and r≥r0. The analytical results were successfully validated against a finite-element numerical model.


Results and Discussion:
The application of the developed analytical solution to a confined circular aquifer with parameters b=7m, r0=3m, θ0=50∘, Q=−100 m3/d, and T=5 m2/d revealed several key hydraulic behaviors. The primary outcome is the clear asymmetric drawdown distribution resulting from the well’s off-center position. The drawdown cone is deepest immediately around the well location and becomes progressively shallower with increasing radial distance, as visualized in the dimensionless drawdown contour plot (Fig. 2). The non-concentric nature of the equipotential lines is distinctly captured in the hydraulic head contour map (Fig. 4), where contours are elliptical and skewed away from the geometric center of the aquifer, demonstrating that symmetry is broken when the well is not at the center. A detailed analysis of drawdown profiles along various angular directions relative to the well’s azimuth further quantified this asymmetry (Fig. 3). The maximum drawdown occurs precisely along the radial line corresponding to the well’s own azimuth (θ=50∘). As the angular deviation from this direction increases, the drawdown magnitude at a given radial distance systematically decreases. For instance, the drawdown along θ=67.5∘ is less than that at θ=50∘, and the profile along θ=90∘ shows even lower values. This pattern conclusively illustrates how the aquifer’s circular geometry and the well’s specific location jointly control the spatial pattern of the cone of depression. Validation against a numerical model confirmed the high accuracy and reliability of the analytical solution. A finite-element model was constructed for the identical aquifer setup. A comparison of the drawdown versus radial distance profiles along two distinct directions (θ=67.5∘ and θ=90∘) showed nearly perfect overlap between the analytical and numerical results (Fig. 8). The minor discrepancies were within negligible numerical tolerance, verifying that the closed-form solution correctly solves the governing equations and boundary conditions without the approximations required in numerical discretization. This successful validation establishes the solution as a robust and efficient tool for predicting head distributions in finite circular aquifers.

Conclusion:
This study successfully developed a rigorous closed-form analytical solution for predicting hydraulic head distribution and drawdown in a finite, confined, circular aquifer subjected to pumping from a well at an arbitrary location. By employing Green's function and Fourier series techniques, the governing equation was solved analytically, resulting in a direct mathematical formula. The solution efficiently captures the asymmetric hydraulic response caused by an off-center well, eliminating the need for numerical approximations. Validation against a finite element model demonstrated excellent agreement, confirming the solution's accuracy. This analytical tool provides a practical and efficient means for well placement optimization, capture zone delineation, and management of circular or near-circular aquifers, such as karst systems. The methodological framework established here also holds potential for extension to more complex hydrological conditions, including heterogeneous or anisotropic properties.

Abstract Introduction:
Groundwater, as a vital resource for drinking water, agriculture, and industry, plays a crucial role in sustainable development, especially in arid and semi-arid regions. In recent years, factors such as climate change, reduced precipitation, population growth, and over-extraction have led to significant declines in groundwater levels and quality in various parts of the country. In this context, underground dams have emerged as innovative water management structures that reduce surface evaporation, increase water residence time, and enhance artificial recharge, thereby improving both quantity and quality of groundwater. Global studies have demonstrated that underground dams can raise groundwater levels, reduce salinity, and control saltwater intrusion; however, improper design or operation may increase nitrate levels and electrical conductivity (EC), posing risks for drinking and agricultural uses. Chaharmahal and Bakhtiari Province, characterized by semi-arid conditions and over 20 meters decline in groundwater levels during the past three decades, provides a suitable setting for underground dam implementation. The first underground dam in the province was constructed in 2015 in the Yancheshmeh watershed. This study aims to comprehensively evaluate the effects of this dam on groundwater quantity, focusing on water level changes and quality, with special emphasis on EC and nitrate concentrations as key indicators of water suitability and potential health risks.
Material and Methods:
This study was conducted in five main phases: desk studies, field operations, laboratory testing, statistical analysis, and result interpretation. The research focused on an underground dam located on the Zayandehrood watershed, with a reservoir length of approximately 5800 meters and a surface area of 3.5 hectares. (1) Desk Studies: Baseline data related to geology, meteorology, hydrology, hydrogeology, geography, and climate of the study basin were collected. A monitoring plan was developed to define sampling points and measurement locations for groundwater level and quality in wells both upstream (outside the reservoir) and within the reservoir. )2( Field Operations: Groundwater levels were measured monthly and weekly during rainy periods in wells within a one-kilometer radius of the dam from spring 2020 to spring 2024. Measurements were taken using a tape and meter. Water samples were collected seasonally and monthly during rainy periods from two points: a well at the reservoir inlet (furthest from the dam) and a well behind the underground dam. Sampling employed mechanical pumping assisted by a tractor. (3) Laboratory Testing: The collected samples were analyzed at the Agricultural and Natural Resources Research and Education Center laboratory for water quality parameters including pH, salinity, cations (Ca, Mg, Na), anions (Cl, CO3, HCO3, SO4), insoluble salts (lime, gypsum), and nitrate concentrations. This aimed to evaluate suitability for drinking and agricultural use. (4) Statistical Analysis: Data were analyzed using SPSS software and descriptive statistics (mean, standard deviation, range, skewness, coefficient of variation) were calculated. Student’s t-test (with three replicates) assessed significant changes over time, while Duncan’s test compared means at a 95% confidence level. (5) Result Interpretation: Annual groundwater level changes and yield variations in two selected wells were analyzed. Correlations between groundwater level and physical-chemical parameters were evaluated, especially nitrate and salts. The Schuler and Wilcox diagrams were used to assess the underground dam’s impact on water quality for drinking and agricultural purposes.
Results and Discussion:
Groundwater level monitoring was conducted regularly from spring 2020 to spring 2024 with 46 measurement events. These events included post-rainfall sampling . The water level fluctuations in Well 1 (inflow area) and Well 2 (within the underground dam reservoir) showed strong correlation, confirming the direct impact of surface water inflow on the stored groundwater volume. Well 2 had an average water level depth of 6.32 m, with fluctuations between 3.4 and 7.8 m, while Well 1 had an average of 5.81 m with variations from 3.9 to 9 m. The coarse alluvial aquifer of the reservoir was estimated to have the volume of 700,000 m³ and an effective porosity of 20%, yielding a potential water storage capacity of about 140,000 m³. Considering an average saturated thickness of 12 m, the usable groundwater volume was calculated to be approximately 100,000 m³. Despite continuous seasonal withdrawal, the reservoir volume replenished annually, which contrasted with pre-dam conditions, under which water was absent during dry seasons. This stable water supply contributed to a 49.3% increase in cultivated land area between 2019 and 2022. Physicochemical analyses of 47 water samples revealed mostly stable concentrations of chemical parameters, except for bicarbonate, carbonate, and nitrate ions which showed significant seasonal changes. Electrical conductivity (EC) increased during dry periods due to water volume reduction but decreased with recharge, indicating natural dilution effects. Nitrate concentrations peaked during irrigation seasons due to fertilizer use but were diluted during wet periods; nitrate levels were lower inside the reservoir, demonstrating the dam’s mitigating effect on contamination. Water quality classification using Scholler, Wilcox, and Piper diagrams confirmed that the water was suitable for drinking and moderate agricultural use. The water type was predominantly calcium-bicarbonate, consistent with local geology.
Conclusion:
The present study demonstrated that the Yan-Cheshmeh underground dam, strategically located in a suitable geological setting and designed based on hydrogeological principles, has effectively contributed to groundwater storage and management. The impermeable foundation, large volume of coarse alluvial deposits, and considerable reservoir depth enable the storage of approximately 100,000 m³ of usable water. This volume remains sustainably available despite seasonal withdrawals, successfully supporting agricultural demands in the region. Water quality analyses revealed that seasonal water retention in the underground reservoir does not degrade water quality; instead, natural dilution reduces nitrate concentrations. Scholler, Wilcox, and Piper diagrams classified the water quality as ranging from good to acceptable for drinking and from moderate to good for agricultural use. A key strength of this research was the integrated approach combining fieldwork, laboratory analysis, and statistical evaluation over multiple years, which enhanced result reliability. However, limitations included the temporal coverage and sample size, which could be expanded for more detailed seasonal analysis. Overall, the Yan-Cheshmeh underground dam exemplifies a successful nature-based infrastructure for sustainable water resource management in semi-arid areas. It is recommended that similar projects be considered by policymakers and water resource

Abstract Introduction: Groundwater is a vital resource for human consumption, agricultural production, and the development of water-related industries, especially in arid and semi-arid regions. Groundwater and surface water resources provide approximately 60 and 40 percent of Iran’s total water supply, respectively, where the relative water consumption in the agricultural, urban, and industrial sectors is approximately 92%, 7%, and 1%, respectively. The construction of many dams on main rivers, along with water extraction, has reduced river flows, dried them up, and damaged river-dependent ecosystems. The inflow to Tashk and Bakhtegan lakes located in Fars province has decreased due to the construction of upstream dams and the use of river water for irrigation in the past decade, leading to the drying of these lakes in 2013. The over-extraction of groundwater by ~5.4 billion cubic meters per year during the 2002-2015 period has resulted in a decrease in groundwater levels (10-100 centimeters per year) in different regions of Iran, averaging 49 centimeters per year nationwide, damaging groundwater-dependent ecosystems in some areas. For example, Parishan Lake, which is mainly the result of the inflow of groundwater from nine springs, has experienced a decrease in water depth (about 5 meters during the 1995-2008 period) due to increased groundwater extraction around the wetland. The Jahrom aquifer in Fars province has also experienced a decrease in water level of approximately 0.75 meters per year, or three aquifers Aspas, Khosrowshirin, and Kamfiruz in the north of Fars province have respectively experienced a decrease in groundwater level of approximately 0.7, 1, and 0.35 meters per year due to over-extraction. Although groundwater is a vital source for human needs and consumption, it is also vital for preserving the environment. The main point in water resources management is the neglect of environmental water needs, in other words, all the water available in a river or aquifer is only considered for human consumption. However, a physical index recently presented by Naderi (2021) takes into account environmental needs and quantifies the level of water resources management based on the concepts of available water and water supply (water extraction). The aim of this study is to quantify the level of management (LOM) of aquifers in Zanjan Province under “normal” and “sustainable” management conditions



Methods: The study area includes eight alluvial aquifers of Zanjan Province (northwestern Iran) which are located between 47010’ to 5005’ E and 35025’ to 37010’ N. About 1.6% of the province’s area has a dry climate, 76% has a semi-dry climate, 20% has a Mediterranean climate, and 2.4% has a semi-humid to humid climate. The aquifers include Tarom, Zanjan, Mahneshan, Moshampa, Sojas, Zarrin-Tappeh, Abhar, and Qeydar, which have areas of 75.5, 1146.13, 30.06, 36.1, 501.7, 495.4, 657.6, and 699.2 km2, respectively. The LOM is quantified under “normal” and “sustainable” conditions. The difference between the two LOM values stems from definitions for existing groundwater sources. Sustainable groundwater originates from the aquifer’s own region, while normal groundwater originates from both the local aquifer region and adjacent groundwaters to meet the region’s water needs.

〖LOM〗_n=(〖AGW〗_n-TWS)/〖AGW〗_n (1)

〖LOM〗_s=(〖AGW〗_s-TWS)/〖AGW〗_s (2)

〖〖AGW〗_n=R〗_n-EFR=(I_p+I_r+I_s+I_irg+I_mi+I_net )-EFR (3)

〖〖AGW〗_s=R〗_s-EFR=(I_p+I_r+I_s+I_irg+I_mi )-EFR (4)

In the above relations, subscripts n and s represent normal and sustainable conditions, respectively. AGW is available groundwater, TWS total water supply, R the recharge of groundwater, EFR the environmental flow requirement, infiltration from precipitation (Ip), groundwater recharge from the river (Ir), groundwater recharge from runoff (Is), groundwater recharge due to irrigation return flow (Iirg) and municipal-industrial (Imi) water use, and net groundwater recharge from adjacent groundwaters (Inet).



Results: Alluvial aquifers of Tarom, Zanjan, Mahneshan, Moshampa, Sojas, Zarrinabad, Abhar, and Qeydar have experienced groundwater storage anomalies of 2.57, -25.61, 3.83, 0.82, -6.46, -9.52, -45.80, and -19.55 million cubic meters per year, respectively. Only the aquifers of Tarom, Mahneshan, and Moshampa have positive changes in storage volume. Results show that in the Mahneshan aquifer, normal management was positive (3 percent) but sustainable management was negative and close to zero (-0.1 percent). Therefore, the type of management is “pseudo-sustainable”. In the Moshampa aquifer, normal management was positive (2 percent) but sustainable management was negative (-9.7 percent). Therefore, the type of management is “pseudo-sustainable”. In the Tarom aquifer, normal management was positive (6.5 percent) but sustainable management was negative (-0.38 percent). Therefore, the type of management is “pseudo-sustainable”. In other aquifers, both normal and sustainable management were negative and indicative of the “mismanagement” class, so that normal and sustainable management in the Zanjan aquifer were respectively -9 and -41 percent, in the Sojas aquifer were -8.9 and -17.7 percent, in the Zarrinabad aquifer were -18.5 and -68 percent, in the Abhar aquifer were -30 and -106 percent, and in the Qeydar aquifer were -14 and -106 percent. Therefore, it is necessary to improve the status of water resource management, using various solutions such as wastewater treatment, education and increasing public awareness in optimal water consumption, reducing the cultivated area, increasing irrigation efficiency, and cultivating crops with less water demand to reduce groundwater abstraction in Zanjan Province.

Abstract Abstract

The use of isotopes, especially stable environmental isotopes, is very important in investigating the water cycle and water resources studies. Preparation of the local meteoric water line and its equation in a region is used to determine the origin of the air mass affecting the region and is used as a basis for a more detailed study of water resources, because by maintaining the initial characteristics of precipitation as an input to the groundwater aquifer, the subsequent changes that occur in the groundwater aquifer will be traceable.



Methods

The studied area is located in Chaharmahal and Bakhtiari province and in Chelgerd, Farsan and Ardal cities, and in terms of structure, it is a part of high Zagros (shredded or eroded). The major part of the study area is located in the large Karun basin and part of it is located in the Gavkhouni basin.

In this research, in order to investigate the isotopic composition of precipitation, a total of 38 rain samples and 7 snow samples were collected from 9 stations at different altitudes with monthly frequency in the 2017-2018 in the form of cumulative and precipitation event in the rainy season. In order to determine the isotopic values of the collected samples, they were sent to Mesbah Energy laboratory and the isotopic composition of oxygen and hydrogen of all samples was determined by a laser spectroscopy.

By examining the composition of oxygen 18 and deuterium isotopes of precipitation samples in hydrological year 2017-2018, the local meteoric water line for the middle Zagros study area in the Zardkoh Bakhtiari area has been drawn and compared with the global meteoric water line and the Meditrranean meteoric water line. In addition, in order to establish a relationship between precipitation isotopes and regional weather conditions, the correlation of altitude, temperature and precipitation parameters on stable isotopes of oxygen 18 and deuterium of event precipitation samples from different altitudes has been investigated. Also, in order to do more detailed studies and determine the origin of moisture masses, the correlation between the amounts of oxygen 18 and deuterium isotopes with deuterium excess and electrical conductivity was also investigated.



Results

By examining the isotopic results obtained from the collected precipitation samples, for the first time, the atmospheric water isotopic line of the middle Zagros region in the Zardkoh Bakhtiari was obtained with the equation δD =7.1068 δ18O+12.364. The local meteoric water line of the region had differences with global and Meditrranean meteoric water line due to the occurrence of evaporation and transpiration from precipitation. The changes of δ18O value in meteoric precipitation in the region are from -12.92‰ to -1.07‰ (average -6.38‰) and δD value is from -80.16‰ to 7.51‰ (average -33.58‰).

Comparing the isotopic content of precipitation in the range with altitude and amount of precipitation indicates that precipitation with richer isotopic composition occurred in areas with lower altitude and amount of precipitation. For every 100 meters change in altitude in this area, about 0.49 and 2.16 permil decrease in δ18O and δD isotopic values, respectively, and for every 20 mm increase in precipitation, about 1.3 permil decreases in δ18O isotopic value and about 10.1 of a permil decrease in the amount of deuterium occurs.

Also, the increase in temperature has led to the enrichment of oxygen 18 and deuterium isotopes in the study area. So that the changes of δ18O and δD of the precipitation samples of the middle Zagros range are about 0.9 and 0.4 permil per 5 degrees centigrade of temperature change, respectively

Also, the amount of electrical conductivity (EC) of precipitation samples has a direct relationship with the amount of oxygen 18 and deuterium isotopes of these samples, so that with an increase of 20 microsiemens per centimeter of electrical conductivity, the amount of oxygen 18 and deuterium isotopes of precipitation samples increase by about 1.45 and 9.40 permil, respectively.

In the conducted studies, the relationship between deuterium excess and isotopic values of precipitation samples was also investigated. deuterium excess of precipitation is usually affected by relative humidity and atmospheric temperature of the source of moisture, which is why it is considered an important indicator in determining the source of moisture. If the cloud humidity drops below 100%, deuterium excess occurs. The increase in the amount of deuterium excess and the decrease in isotopic values of δ18O and δD of precipitation in the study area also indicate the main origin of moisture masses from Mediterranean regions.

Abstract Introduction:

According to the ranking of the World Resources Institute, Iran ranks 14th in water stress in the world, and is among the 20 countries with the highest water stress in the world. The current process of extracting underground water resources in Iran is an unstable process and its continuation will cause serious irreparable damage to the quantity and quality of aquifers. The security of underground water resources is considered more complicated in some provinces of Iran due to the degree of dependence on underground water resources. About 85% of the water needed in Alborz province is supplied by relying on ground water sources, and the population growth of Alborz province is more than three percent and twice the average population growth of the country. This has caused Alborz province to suffer unbalanced development in all fields; Alborz water resources are not able to respond to this unbalanced development and this has caused water tension in Karaj metropolis and surrounding cities and even villages. The unbalanced development process of Alborz province in recent years has aggravated the security crisis of underground water resources and water stress. With the growth of demand in the future, the competition for water resources will increase and the sustainable management of underground water resources is considered as a challenge in the region. Among the approaches of sustainable management of water resources, Water-Food-Energy Nexus provides the necessary prerequisites for the sustainable management of existing limited resources in an integrated manner.

Methods:

The present study deals with the dynamic modeling of sustainable management of underground water resources based on the security of water-food-energy nexus resources and analyzes the solutions of sustainable management of underground water resources according to the trend of population changes, economic growth and the development of renewable energy sources. It is for this purpose, a dynamic model was designed using time series data, and after validation, the model was simulated in a twenty-year horizon. The base year in the model is 2011, and time series data from 2011 to 2016 were used to evaluate the behavioral validity of the model. Validation of the model included goodness of fit tests, dimensional consistency tests, boundary adequacy tests, behavior reproduction tests, and integration error tests. Also, in terms of behavior, the behavior of the model variables was approved by the experts.

Results:

According to the results of model sensitivity analysis and feasibility studies of operational plans for water resources management in Alborz province and with the participation of Alborz regional water policy makers, three scenarios to improve the security of underground water resources with regard to the link between the security of water and food resources -Energy was considered: 1- The security of underground water resources based on the optimal exploitation of water supply resources, including the policy of artificial feeding of aquifers: the policy of blocking unauthorized wells and controlling withdrawals. Unauthorized and the policy of building and operating systems for storing and extracting rainwater and gray sewage effluent and reuse, 2- The security of underground water resources based on the management of agricultural water demand, including the policies of the development policy of irrigation systems, the policy of promoting the model suitable cultivation with climatic conditions and ecological power and the policy of reducing agricultural waste during the production period and the policy of developing the performance of agricultural products and the development of mechanized cultivation and 3- the security of underground water resources based on the management of electric energy demand, including the policies of the policy of consumption optimization and Reduction of electrical energy loss, the policy of building a power plant for heat recovery from industrial processes, the policy of exploiting the potential of solar renewable energy was designed and a group of policies were identified. The findings of the WFEN-SD model indicate that the combined policy is the best solution for the sustainable management of underground water resources and includes: artificial feeding of the aquifer 10 million cubic meters annually; Organizing and controlling withdrawal from wells; Exploitation of gray wastewater and reuse and supply of 10% of agricultural water; 10% development of irrigation efficiency with new irrigation systems; 10% reduction in agricultural waste; 10% development of agricultural products yield by seed improvement, plant preservation and pest control and mechanized cultivation support policies; 5% reduction of electrical energy loss in combined cycle power plant and development of solar pumping systems in the agricultural sector.

Abstract Introduction:

The dams and reservoirs are usually designed with a certain capacity to meet agricultural, urban and industrial needs. Karst terrains are typically considered inappropriate for dam construction because of their complex geological and hydrogeological characteristics. The Tangab Dam with a reservoir volume of 140 million cubic meters was built to control river flood and supply part of downstream agriculture water. Geologically, the dam and reservoir are located at the entrance of a karst valley, on the northern limb of the Podeno Anticline, in the simply folded Zagros Zone. The Podeno Anticline is made mainly of Pabdeh marlstone, Asmari limestone, alternating layers of limestone and marlstone of a transitional zone, and Razak marlstone. By beginning of impoundment in 2009, the reservoir has faced with a leakage problem. In order to reduce water leakage, the additional grouting and treatment works were designed and executed at dam site. In this research, an attempt has been made to investigate the function of additional grouting and treatment works on reducing the hydraulic connection between the reservoir and downstream groundwater.



Methods:

The geologic map of the study area was prepared based on a geological map provided by the Geological Survey and Mineral Exploration of Iran. Water level in the reservoir and boreholes were measured monthly during a five years period by the Fars Regional Water Authority. The grouting history at the dam site was determined based on the available reports. The dam site was divided into three sectors including the left abutment, riverbed and the right abutment. At each part, effect of the initial grouting and treatment works on the changes in the groundwater level was investigated. Pearson coefficient was used to determine correlation between the reservoir water level and water level in downstream boreholes.



Results:

The initial water tightness system of the Tangab Dam includes a cut-off wall implemented in the riverbed and a 180 m deep grout curtain with 256 and 216 m extension respectively into the left and right abutments. By starting of reservoir impoundment in 2009, discharge of the downstream springs was increased (from 1.4 to 3 m3/s) due to water losses from the reservoir. To reduce further leakage, two additional grout curtains with 300 and 570 m extensions were executed respectively in the left and right abutments. Moreover, additional grouting was done at different parts of the initial grout curtain.

At the left abutment, similar fluctuations were observed in the reservoir water level and downstream groundwater. The calculated correlation coefficient between the reservoir water level and water level in boreholes located upstream and downstream of grout curtain varies between 0.80 to 0.96 and 0.70 to 0.89, respectively. About 50 m difference between the reservoir water level and water level in downstream boreholes shows an acceptable performance of grout curtain at the left abutment. At the riverbed, it seems that the cut-off wall and grout curtain works appropriate because the boreholes located in the dam foundation did not show considerable relation with the reservoir (correlation coefficient between 0.06 and 0.12). At the right abutment, the lowest correlation between the reservoir and the boreholes water levels was observed in the RG2, ARG2 and RG6 galleries. Remedial works in these sections have also cause several meters falling in downstream water level. It appears that the closest relation between reservoir water and downstream groundwater was observed along the 570 m long grout curtain constructed at the reservoir bank. Here, it was concluded that permeable sections were remained in the rocks located at the upper levels (especially more than 1420 meters) because a significant rising in groundwater was observed in response to the 25 m rising in the reservoir water level.

Results of this research show that the initial grout curtain and the additional treatment have worked successfully in reducing the rock permeability and also increasing the length of leakage paths. However, reservoir water could be leaked by moving through, below or by passing the ends of the hanging grout curtain which is not connected into the impermeable rocks in depth and at the ends. To reduce leakage from the Tangab Reservoir, the additional treatment needs an extensive and expensive grouting works. Also, achieving a complete sealing of the reservoir is not guaranteed even with the execution of this grouting. Therefore, it is suggested that no other grouting operations be designed and implemented at this site, because the leaked water through the Asmari Aquifer is not unused. Deep percolation of karst water is limited by the Pabdeh marlstone at the bottom of the aquifer. If the reservoir water moves along the edge of the anticline towards the plunge area, it will recharge the karst aquifer and use in future. If the reservoir water moves to the southern limb of the anticline, it will discharge through the downstream spring and use for the local agricultural purpose.

Abstract Introduction:

In arid and semi-arid regions, groundwater is the main source of development of sectors (industrial, agricultural, domestic). And with the increase in demand for water due to population growth, irrigation of agricultural lands and industrial development, exploitation of groundwater resources has also increased. This issue, combined with droughts and the consequences of climate change, has reduced the groundwater level in arid and semi-arid regions. In order to supply the lack of surface water, as well as to overcome drought in emergency situations and sustainable management of groundwater resources, installing a managed aquifer recharge system (MAR) to recharge groundwater using flood and surface water in a long-term is important and necessary. The methods of artificial recharge are diverse and depend on the need, facilities and many factors that affect on artificial recharge. Due to this issue, tools such as geographic information system (GIS) are very useful for finding the best places to recharge groundwater. Identifying the groundwater recharge area is an important factor for achieving success and managing water resources in any region. The purpose of this research is the optimal management of surface and groundwater resources using a hybrid modeling pattern in order to increase the stability of the groundwater resources system and reduce its quantitative and environmental issues in the study area. Therefore, in this study, the identification and management of groundwater recharge was carried out in the Shahriar Plain located in the western outskirts of Tehran, Iran.

Methods:

In this research, a simulation pattern was presented, according to which, first, the best artificial recharge place was determined by fuzzy and weight method using GIS model in Shahriar plain. Then, HEC-RAS hydraulic model was used to calculate the parameter (the ratio of infiltration debi to flood debi) in the Karaj river. In the next step, two independent models for flood routng in the river and reservoirs of the artificial recharge system were defined by the HEC-HMS model. In the first model, the parameter of the ratio of infiltration debi to flood debi was used in the Massingham-Kange method to determine the flood routng in the river, and in this way, the amount of flood entering to the artificial recharge plan was estimated. In the second model, flood routng was carried out in the reservoirs of the recharge plan and the amount of infiltration, storage and recharge was calculated by the plan. And finally, the amount of recharge in the artificial recharge plan was simulated using the artificial neural network (ANN) model, and the performance of the artificial recharge system and the groundwater level changes resulting from it were estimated.

Results:

According to the fuzzy and weight analysis, the best place for artificial recharge in the entire studied time horizon was considered to be alluvial fan in the north of the plain. The area of the suitable (good) region obtained by the fuzzy method was calculated to be 8.62 percent more than the weighted method, and the performance of the fuzzy method in estimating the suitable locations was evaluated better than the weighted method. The maximum volume of flood entering the recharge plan from the HEC-RAS model and the first HEC-HMS model in the studied period is 8.56 and 8 (MCM), respectively, and the minimum value of this variable from the HEC-HMS simulator is 0.87 (MCM) and in the case of the HEC-RAS model, the same amount was estimated. The results indicated that the maximum and minimum flood volumes entering to plan are related to the maximum and minimum floods occurred. The total amount of artificial recharge resulting from the HEC-HMS model, in the entire time period studied, without considering the flood output from the recharge plan, was computed as 37.6 (MCM), and the amount of total recharge for the neural network model was computed as 36.3 (MCM). Also, the total level changes due to recharge of the plan resulting from the estimation of the simulator and the neural network model in the entire study period are equal to 1.59 and 1.53 (m), respectively, which indicates the appropriate accuracy of the neural network model. Also, the level changes caused by recharge in the plan and the river in the entire period of desired time was computed to be 1.88 (m). In total, the reserve performance of the plan in the entire period of desired time was 54 percent and the recharge performance of the plan was 89 percent, and the performance of the entire artificial recharge system including (river section and artificial recharge plan) in recharge applications was computed at 90 percent. Therefore, the results of the simulation pattern and the performance of the artificial recharge plan in recharging were evaluated as suitable and acceptable. Finally, according to the results of the hybrid modeling pattern, at the same time, floods, surface and groundwater resources and artificial recharge system are under control, and based on available water resources, increasing the stability of the groundwater resources system and reducing quantitative and environmental issues related to water resources can be managed and controlled according to the existing conditions.

Abstract The shape of the karst spring hydrograph is a direct reflection of all the physical processes that affect the flow of underground water inside the aquifer. Especially, the shape and process of the recession curve provides important information about the storage and hydrogeomorphological characteristics of the aquifer mass supplying the spring. In this research, a quantitative analysis of the hydrogeological behavior of Dimeh and Pirghar karst springs in Chaharmahal and Bakhtiari provinces located in the high and folded zones of Zagros during the common statistical period (from 2000 to 2019) have been quantitatively analyzed. This analysis includes classification of karst aquifer, modeling of hydrograph recession curve and estimation of water volume stored in saturated and unsaturated part of karst aquifer by Mangin method. . Estimation of the coefficients of recession components of fast flow (αf), transfer flow (αif) and base flow (αb) of springs based on the analysis of 18 recession curves obtained αf = 0.004، αif = 0.016 and αb = 0.042 for Dime spring and αf = 0.007، αif = 0.038 and αb = 0.125 for Pirghar spring revealed that the degree of development of Pirghar spring is 7 and Dime spring is 5.5;The analysis of the time series results shows that the discharge of Dimeh spring is under influence of majority of open, medium-sized fissure and with smaller influence of connected conduits, but the Pirghar spring hasa a system developed karstification of the aquifer, formed by large open tectonic faults and karstic channels. The high transfer flow rate of Pirghar spring shows the point charge and channel system of the karst region.

Abstract Shortage of fresh water resources and salinization of aquifers are two major development challenges in arid and semi-arid regions. Population growth, industry development, agricultural development in order to provide the required food resources and climate change has increased the uncontrolled abstraction of groundwater resources, which in turn has led to a decrease in groundwater quality, especially in arid and semi-arid regions. The purpose of this study is to investigate the main reasons for salinization of Kashan aquifer, one of the critical aquifers in Isfahan province, which is located near the salt lake. For this study, 53 wells located in Kashan aquifer were investigated. After selecting wells with suitableconditions, 74 water samples were collected from selected wells and chemically and ionically (EC, Na +, K +, Ca2 +, Mg2 +, Cl-, HCO3-) were studied. According to the results, the direction of groundwater flow in this aquifer is from the west to the east of the aquifer, with the exception of the northeastern region of the aquifer where there is a return flow from the salt lake to the inside of the aquifer. The results of this study showed that salinity of Kashan plain aquifer in different regions has two main reasons: in the central and southern regions of the aquifer, the reason for salinity is the uncontrolled abstraction of groundwater from exploitation wells, conical rise of saline water and the occurrence of upconing phenomenon. In the northeastern regions of the aquifer, there is a return flow from the salt lake and the intrusion of salt water into the aquifer.

Abstract Introduction:

The purpose of this study is to evaluate the balancing strategies of groundwater resources in order to adapt to climate change. Accordingly, the simulation of two parameters of precipitation and temperature in Hashtgerd region with three climatic models HadGem2Es, EC-ERATH and GFDL-CM3, was performed using three emission scenarios RCP2.6, RCP4.5 and RCP8.5. Groundwater resources are one of the most important sources of water supply in arid areas, especially in areas facing surface water shortages. This shortage, along with climate stress, has made the water resource utilization system complex. The complexities of water resources systems along with unplanned exploitation of groundwater resources and the strong dependence of operators on it have made the development of a systemic approach in water supply and demand management for development clear. Due to the decline in groundwater aquifers, management of abstraction from these resources and control of abstraction is very important and many aquifer equilibrium scenarios have been proposed to achieve this goal.

Methods:

Hashtgerd study area with code 4105 is in the division of National Water Resources Management Company-Ministry of Energy located in the west of Alborz province with an area of 1170.6 square kilometers, and with alluvial aquifer with an area of 410.7 square kilometers (Figure 2). This study area is located in the northern half of the Namak Lakebasin. Kordan river, the most important surface water source of this region, originates from the northern part and after passing through the central areas of the plain, it leaves the southern part. Most of the water resources in this area are exploited by wellsAfter climatic simulation, exponential down scaling was performed using LARS-WG v6 model. After evaluating the effect of climate change in the region, in order to evaluate the quantitative status of the aquifer, simulations were performed using the MODFLOW model and the prediction of the future situation under climate change conditions was analyzed.

Results:

The results of climatic simulation showed that the simulated values in comparison with the observational data indicate an increase in average precipitation and a decrease in temperature in most months of the year. The difference between the values obtained at the statistical level of 95% indicates a significant difference and appropriateness of simulation results. On the other hand, the quantitative results of the quantification of the aquifer indicate the continuation of the aquifer decline trend and the extracted results show that the highest rate of decline is recorded in the RCP 8.5 release scenario and the lowest rate is recorded in the RCP 2.6 scenario. The rate of aquifer drop in RCP 2.6 scenario was obtained in three models between 7.8 to 8 meters, in RCP 4.5 scenario between 7.9 to 8.8 meters and in RCP 8.5 scenario between 8.5 to 9.7 meters. After evaluating the future situation, aquifer equilibrium scenarios were analyzed in order to adapt to climate change in the region using 5 evaluation strategies by evaluating the relative improvement of the aquifer. The results of balancing strategies showed that in the scenario of drinking water supply through Taleghan dam and replacement of water from wells in the region, it was determined that 20 million cubic meters of water should be allocated for Hashtgerd drinking water supply and replace 20 million cubic meters of water extracted from wells. It becomes. Accordingly, in this scenario, while transferring water and considering the return water coefficient of drinking consumption of 60%, it was determined that a volume equivalent to 32 million cubic meters of water is taken less than the aquifer. The results obtained from the application of various balancing strategies in Hashtgerd aquifer indicate that the aquifer decline continues during the forecast period until the end of the 2024-2025 water year. Examination of the simulation scenarios shows that S1 solution, which is a 15% reduction in water abstraction from the aquifer, has shown the highest efficiency in all three scenarios of climate diffusion in the aquifer. 5. and RCP2.6 will occur at 4 and 3.2 m, respectively. The results also showed that the highest degree of uncertainty in the results of the aquifer level is related to S1 solution and shows a difference of 1.15 meters in the results of diffusion scenarios. The results of this study indicate the importance and necessity of developing strategies for balancing groundwater resources in all study areas of the country, which will be more acute in the event of climate change.