JOURNAL OF AQUIFER AND QANAT
Year:2025 | Volume:6 | Issue:1|Papers Count:12

Rapid population growth combined with socio-economic development and climate change have caused major problems worldwide. The decline in water resources in arid and semi-arid regions is an example of these problems because in recent years, rainfall has decreased and socio-economic activities have increased. This situation has led to water stress and the need for water resource management in the Khorramabad watershed. Therefore, in this study, the effects of climate change on water resources in different scenarios were investigated using ANFIS and MODFLOW models. First, the current conditions of existing surface and groundwater resources were simulated monthly using ANFIS and MODFLOW models. Then, the climate change, ANFIS, and MODFLOW models were combined. After combining the models, the status of surface and groundwater resources in the future (2025-2060) was investigated using the results of SSP scenarios (SSP1-2.6, SSP 2-4.5, and SSP 5-8.5). In SSP scenarios, the annual average precipitation decreases and the annual average minimum and maximum temperatures increase. Based on the results of combining SSP scenarios with ANFIS and MODFLOW models, the annual average river discharge, groundwater level, and aquifer storage under SSP scenarios decrease compared to the average of the base period. The results showed that due to climate change and in SSP scenarios, agricultural water supply will be problematic. By implementing the irrigation plan, a large part of the agricultural water requirement under climate change conditions will be met. Also, in SSP scenarios, compared to the current irrigation method, groundwater level drop will decrease and aquifer storage will increase.

As a masterpiece of ancient Iranian water engineering, qanats have played a vital role in the desert province of South Khorasan and are known as one of the most important sources of agricultural and drinking water supply in Birjand County; Studying the status of water resources and obtaining a water database in watersheds, especially in various desert areas, is of great value, which can lead to correct and fundamental decisions to solve the problem of water shortage in these areas. For this purpose, studying and analyzing the effects of hydro morphological characteristics on qanat discharge is of great importance. In this research, to study the effect of hydro morphological characteristics of the watershed on the discharge of qanats, a case study was conducted on the discharge of 32 qanats in Bagheran Rural District, Birjand County, located in South Khorasan Province. In line with this goal, using topographic maps and satellite images, morphometric parameters such as channel rank, main channel length, surface flow length, shape coefficient, concentration time, average slope of the main channel, main slope of the watershed, upstream watershed area and the environment of the watershed under study were calculated. The results of the studies conducted on 32 qanats in Bagheran Rural District show that, based on the principal component analysis (PCA) method, the concentration time parameter and average slope of the main channel have the greatest impact on the discharge of the qanats in the study area. It is suggested that biological and biomechanical methods (floor dams)

Despite differences in the physical characteristics of porous media, flow intensity and average velocity can be identical at various points within aquifers. Under such conditions, solute transport is influenced by pore-scale factors such as grain size and pore water velocity. Therefore, in order to better understand adsorption/desorption coefficients and solute transport processes, simulation is essential.This study was conducted to investigate the effect of porous media grain size on solute transport under uniform hydraulic conditions using laboratory experiments and both equilibrium and nonequilibrium numerical simulation models. The laboratory columns were made of PVC, with a length of 25 cm and an internal diameter of 8 cm, and the porous media consisted of natural sand and gravel particles. Potassium nitrate was used as the tracer and injected into the soil columns in a pulse-input manner.According to experimental results, the peak concentration (C/C₀) in fine, medium, and coarse-grained media was 0.50, 0.27, and 0.30, respectively, and their distribution coefficients (K_D) were 23.2, 1.8, and 2.1 L/kg, respectively. These results indicate greater dilution of solutes in coarse-grained media and increased retention in fine-grained media.Simulation results showed that nonequilibrium dual-site (RMSE = 0.01) and single-site models (RMSE = 0.01–0.03) provided better accuracy compared to the equilibrium model (RMSE = 0.01–0.09), suggesting the presence of time-dependent kinetic processes in solute transport. Therefore, incorporating both kinetic and equilibrium-based models is recommended for simulating solute transport in porous media.

Identifying qanats as examples of geocultural heritage not only highlights their historical importance, but also provides a basis for the development of geotourism knowledge—knowledge that addresses the introduction and sustainable exploitation of natural resources with geological value. In this regard, the aim of this research is to identify and explain the position of qanats as part of geocultural heritage and to examine their role in the geotourism industry and sustainable development. The present research is descriptive-analytical in nature and method and was conducted by studying documents and library resources. The results indicate that qanats, as prominent manifestations of the coexistence of geological and cultural heritage, have become an unparalleled model of intelligent human interaction with nature. Within the framework of the geotourism industry, qanats have a multifaceted capacity for the development of sustainable tourism. Combining geological, engineering, cultural, and aesthetic aspects, these structures have the potential to be considered educational, experiential, and cultural geosites. In addition, qanats can play a pivotal role in sustainable development. Their capacity for water resource management, job creation, sustainability of rural livelihoods, and transfer of indigenous knowledge provides a valuable context for achieving sustainable development goals at local and regional scales. Therefore, it is necessary to adopt multi-sectoral approaches to the conservation of qanats that combine legislation, education, scientific research, local participation, and the use of technology.

Qanats, as historic hydraulic structures and indigenous climate change adaptation strategies reliant on groundwater resources, demonstrate the vital role of aquifers in water storage and enhancing climate resilience, particularly against natural hazards like floods. This research examines the trajectory of legal frameworks addressing climate-induced natural disasters in developing countries, emphasizing indigenous capacities such as qanat systems and artificial aquifer recharge. Utilizing qualitative content analysis within Ostrom''s Social-Ecological Systems (SES) framework, data were compiled from the global climate change law database, encompassing officially published legal documents from 1957 to 2021. Findings reveal increased legislative attention to climate risk management in recent decades, notably in Africa and countries including Bolivia, Mexico, and the Philippines. Analysis of the three SES systems shows the Resource system consistently dominated legislation, with the "Land Use, Land-Use Change and Forestry (LULUCF)" subsystem receiving the highest focus; within the Actor system, Transportation garnered the most attention, while the National Economy was predominant within the Governance system. Identified laws extend beyond crisis management to establish critical frameworks for local and international cooperation, exemplified by Ethiopia, India, and Tuvalu establishing dedicated funds for natural disaster prevention, preparedness, or compensation, and by Madagascar and Cambodia integrating national disaster risk management strategies into development plans. The expansion of such legal mechanisms is expected to strengthen the adaptive capacity of developing nations facing climate challenges. Consequently, qanats, as an environmentally sustainable adaptation strategy and an exemplary Iranian indigenous model, hold significant potential for enhancing climate resilience.

In recent years, global warming, climatic fluctuations, and the pressure of water resource extraction have led to a decline in groundwater levels. Therefore, to prevent the intensification of the above trend and to optimally manage the exploitation of groundwater resources in plains, simulating and predicting groundwater levels is essential and inevitable. To predict groundwater level changes in the Kuhdasht aquifer, meteorological parameters were first predicted and analyzed using the CIMP6 General Circulation Model under various scenarios. Then, using temperature, precipitation, and aquifer extraction data from the 2002-2022 statistical period, the performance of hybrid Artificial Neural Network-Wavelet (WANN) and Artificial Neural Network-Creative Shooter (CSO-ANN) models in estimating groundwater levels was investigated. In the next step, using the selected hybrid model, groundwater level changes in the region were predicted for the 2022-2042 statistical period. The results from the General Circulation Model indicated that with increasing temperature, precipitation decreases. The simulated temperature in all investigated climate models (SSp126, SSP245, and SSP585) for the future period (2022-2042) showed an increase compared to the baseline period in all months, while the average precipitation did not show a clear trend. Furthermore, the modeling results showed that the Artificial Neural Network-Wavelet model performed better than other models in estimating the groundwater level of the Kuhdasht plain. The results from the selected model also indicated a groundwater level decline of 3 to 4.5 meters in this plain during the years 2022-2042.

The Groundwater Quality Index (GWQI) is used to assess the quality of groundwater and its suitability for various purposes. This index is employed by integrating data and generating a single number that reflects the overall quality of the water. In this study, changes in groundwater quality in the Qazvin aquifer were examined using GWQI over a 15-year period ending in 2021. In this regard, we used a wide range of water chemistry parameters, including Na, K, Mg, Ca, SO4, Cl, HCO3, pH, TDS, EC, and TH. The results showed that the minimum GWQI value ranged from 6.18 to 2.24, while the maximum value ranged from 1.118 to 2.205. Among the water chemistry parameters, EC and K had the highest and lowest impact on the GWQI value, respectively. The results of the Mann-Kendall trend test also indicated no significant trend in the GWQI index. Spatial analysis of the results revealed that the minimum values of GWQI were located in the northern and northwestern parts of the aquifer, while the maximum values were found in the western part of the aquifer. It is essential to note that the geographic area corresponding to the minimum GWQI values were much broader than that of the maximum values, indicating suitable groundwater quality in most regions.

The central regions of Iran, located within arid and semi-arid climatic zones, have historically faced significant challenges in securing adequate water resources for both domestic consumption and agriculture. Consequently, the inhabitants of these areas developed a variety of adaptive strategies to ensure water availability. Over time, these strategies encompassed not only the management of groundwater resources but, in certain localities, the efficient harnessing of surface water as well. Khusf County, situated in southern Khorasan, provides a remarkable case study in this regard. Here, local communities constructed hydraulic installations such as bandsars (earthen dams) and cisterns (āb-anbārs) along the paths of seasonal runoff, thereby securing water for irrigation and drinking purposes. This research, based on systematic archaeological surveys combined with topographic analysis in a GIS environment, seeks to identify these structures and to elucidate their spatial distribution and functional role in surface water management. The findings indicate that the placement of these hydraulic features was closely aligned with the region’s topography and natural landscape, ensuring optimal utilization of surface water resources. Specifically, bandsars were constructed at higher elevations and in proximity to alluvial fans, typically away from settlement centers, while cisterns were positioned at lower elevations near residential areas. The siting of cisterns on steeper slopes facilitated the rapid conveyance of water with minimal sediment deposition, whereas bandsars were placed on gentler slopes where reduced water velocity enabled both the accumulation of water and limited sedimentation.

Climate change, as one of the most significant environmental challenges of the 21st century, has extensive impacts on global temperature. In the present study, in order to reproduce the maximum temperature variable, monthly maximum temperature data from the Tabas meteorological station for the period 1990–2014 were used. The years 1990–2007 were considered for calibration and 2008–2014 for validation. To analyze the maximum temperature, a bias correction method based on quantile mapping was applied using coding in the R software environment with the help of the Qmap package. The performance of the models was evaluated using the statistical indices RMSE and KGE, and the superior model was selected through a weighting approach. In this regard, the outputs of two global climate models, IPSL-CM6A-LR and MPI-ESM1-2-HR, from the CMIP6 project (raw data) and the ISIMIP project (bias-corrected data) were analyzed, and their performance in reproducing maximum temperature was assessed and compared. The results indicated that ISIMIP models performed better than those of CMIP6. Accordingly, the superior ISIMIP model was employed to simulate changes in maximum temperature for the future period 2030–2050 under the SSP5-8.5 scenario. The results of these simulations revealed a continuing increasing trend in maximum temperature in the region, leading to serious consequences such as intensified heat stress, increased evapotranspiration, reduced aquifer recharge, declining groundwater levels, and more severe droughts. This study highlights the importance of utilizing accurate models in local climate studies, especially in vulnerable regions

Due to the importance of groundwater in arid and semi-arid regions and the role of balanced discharge from Qanats in the utilization of groundwater which does not harm the reservoir and does not cause reservoir deficit as what we have in pumping, and considering the preservation of these valuable resources in the ancient engineering of Iran, and the maintenance of the water quality of these sources, especially in areas which being used for drinking and agricultural purposes; and also noting that until now, the determination of quantitative and qualitative protection zone for these water resources has been neglected, relying solely on guidelines for defining well protection zone, which creates many technical issues when applied to Qanats; therefore, it is necessary to take action in this regard. Therefore, this research aims to provide recommendations for appropriate qualitative protection zone determinations for the benefit of operators, experts, and researchers in this field. This is achieved by reviewing all existing research and documents in this area and studying methods for determining qualitative protection zone of other groundwater sources, taking into account water production zone (wetland), water transport zone (dray land), transient time, transmissivity, and other technical characteristics of Qanats, which will be explained in the fallowing.

Industrial units located in refineries pose a serious threat to groundwater resources due to the leakage of petroleum and hydrocarbon pollutants. This study was conducted to assess the extent of contamination, identify the source of leakage, and examine the potential pollution of a nearby rural drinking water well adjacent to one of the country’s refineries. For this purpose, monitoring wells within the refinery, distribution and pipeline storage facilities, and agricultural wells in the village were sampled. Using an oil detector device, parameters such as the thickness of light non-aqueous phase liquid (LNAPL) contamination and water table levels were measured over different months. Furthermore, during four sampling phases, the types of dissolved petroleum contaminants present in the aquifer were identified. The findings indicate that the village’s drinking and agricultural wells are free from hydrocarbon contamination. In contrast, three wells within the refinery area showed LNAPL contamination, and twenty-two other wells exhibited dissolved benzene contamination. Based on the pollution distribution maps, eight high-contamination zones were identified in the study area. The results indicate that the primary source of the pollutant leakage is mainly due to failures in the industrial wastewater transfer system (OSW) and associated sumps. Therefore, immediate actions to replace and renovate the OSW system are strongly recommended to mitigate environmental risks.

Rainfall-runoff modeling is one of the key tools in hydrology to determine flood characteristics such as the amount and time of peak discharge.The IHACRES model parameters were calibrated using the objective function to maximize the Nash-Sutcliffe index. The simulation values of peak flow rate and peak flow time were calibrated and validated using the Ns and R2 evaluation criteria. In the ARMAX method, it was 0.79 and 0.85, which indicates the acceptable performance of simulating peak discharge values and the time to reach peak discharge in the ARMAX method. In the validation stage, the values of the evaluation criteria in the ARMAX method were estimated to be 0.54 and 0.64, respectively, which indicates that the ARMAX method has a desirable performance. Overall, the research results indicate that the results obtained from the IHACRES model in the study area, using the ARMAX method, have had an accurate performance.