Maryam Naeimi; Adel Jalili; Samira Zadifar
Volume 32, Issue 2 , July 2025, , Pages 160-184
Abstract
Background and objectivesGroundwater resources can be collected through wells, tunnels, and drainage paths; or inherently percolate to the surface through seepage or springs. It is consumed for drinking, agriculture, industry, environment, and ecosystems (Asadi et al., 2023). Management of underground ...
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Background and objectivesGroundwater resources can be collected through wells, tunnels, and drainage paths; or inherently percolate to the surface through seepage or springs. It is consumed for drinking, agriculture, industry, environment, and ecosystems (Asadi et al., 2023). Management of underground water resources is particularly important in arid and semi-arid regions, due to surface water is scarce. Hence, the dependence upon groundwater is quite remarkable. Evidence shows that factors including population growth and climate change play a crucial role in the intensification of groundwater levels (Hall et al., 2008).Lack of proper knowledge and excessive exploitation of underground water resources, irreparable damages such as a sharp and irreversible drop in the underground water level, reduction of the flow rate of wells and canals, changes in the pattern of underground water flow such as the advance of waterfronts. It has followed the saltiness and interference of salty waters. Therefore, in this research, the quantitative characteristics of underground water in the central desert watershed during the statistical period of 2001-2002 to 2017-2018 have been evaluated.Research MethodologyThe drainage basin of the central desert is a part of the great section of central Iran, which includes important cities such as Garmsar, Semnan, Damghan, Shahrood, Neishabor, Mashhad, Sabzevar, and Kashmer, creates an area of 226,523 Km2 between the south of Alborz and the northeast of Zagros. Considering the necessity of studies on the factors affecting the decline of the water level of groundwater resources, including hydrogeological droughts and human interventions, along with behavioral assessment; it is essential to provide appropriate protection and management solutions for groundwater resources.Hence, in the present study, various time lapse-year aligned maps, representative hydrographs of the study area, the average annual changes in precipitation and groundwater drought index (GRI), and the level of exploitation of groundwater resources for the target plain were calculated. To evaluate the quantitative status of underground water, the water level and the observation wells data in the aquifers of the study areas of the Central Desert watershed were used in the mentioned statistical period. In the following zoning maps, variations of underground water level fluctuations, aquifer storage volume, and drought conditions were analyzed. It is necessary to note that all the maps were drawn using Arc GIS and kriging tools.Results The results at the level of the central desert watershed, based on the updated statistics up to the water year 2019-2020, indicate the number of 29,360 underground water sources (wells, springs, and aqueducts) with the volume of discharge and withdrawal of 3659 million cubic meters per year. The number of springs, aqueducts, and deep and semi-deep wells is about 19, 21, 39, and 21% respectively in terms of number and terms of discharge about 9, 16, 72, and 3% of the total number and discharge of underground water sources.An annual survey of the number of groundwater resources in the study areas shows that the trend of deep wells increased until 2011 and then decreased. Increasing the number of wells can increase the exploitation of groundwater levels, and unprincipled management in the exploitation of groundwater resources for agricultural development causes a drop in water levels and a decrease in the qualitative value of groundwater resources, and subsequently turns dry areas into critical centers of wind erosion (Nasirian et al., 2018).In general, in most of the study areas, the rate of discharge from wells is much higher than that of springs and qanat. Therefore, the dominant system of groundwater exploitation is deep wells. Groundwater extraction by deep wells has increased significantly in different years, while its consequences could be seen as a direct impact on the existence of qanats, springs, and their average water supply. On the other hand, a decreasing trend in deep wells could be due to excessive extraction in previous years and well-greening events in the study area. Previously, excessive extraction of groundwater resources in the plains of the central desert such as Neyshabur (Rokni et al., 2016) and its consequences such as a water level depletion (4.8 meters in the ten years 1996- 2006), land subsidence, and a decline in water quality have been mentioned.Also, the most water level changes have occurred in the Rashtkhar, Ivanki, and Kashmar areas, which have a deficit of -29.30, -25.50, and -18.40 meters, respectively. The annual and cumulative changes in the storage volume of the reservoir in the Central Desert watershed area during the statistical period of 1998 to 2018 show that the volume of the reservoir has decreased by 25317 MCM. The continuation of the changes in the GRI shows that the first drought occurred in 2019, while the general trend of the GRI value was decreasing.ConclusionsGenerally, in most of the study areas of the central desert integration area, the amount of discharge from wells is far more than from springs and qanats. Therefore, the dominant system of using underground water is in the form of deep and semi-deep wells. Additionally, the results indicate the unsustainable use of water to maintain and expand human activities in the largest area of Iran, located in the arid/semi-arid sector. If not controlled, such excessive use of underground water can cause environmental problems and serious socio-economic consequences. Finally, due to the unpredictability of climatic droughts and the impossibility of preventing them, it is necessary to reduce their negative effects by planning and applying proper management of underground water resources.
Yaser GHasemi Arian; Hadi Eskandari Dam aneh; Maryam Naeimi; Adel Jalili; Samira Zandifar; Azadeh Gohardoust; Sakineh Lotfinasabasl
Volume 32, Issue 1 , May 2025, , Pages 1-17
Abstract
Background and objectivesLand subsidence, primarily caused by excessive groundwater extraction, constitutes the most advanced and irreversible stage of desertification and land degradation. While this phenomenon poses a significant threat to numerous plains and major urban centers across Iran, existing ...
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Background and objectivesLand subsidence, primarily caused by excessive groundwater extraction, constitutes the most advanced and irreversible stage of desertification and land degradation. While this phenomenon poses a significant threat to numerous plains and major urban centers across Iran, existing desertification assessment models have largely overlooked subsidence rates and the agricultural sector's substantial groundwater consumption. This study evaluates desertification intensity in the Qaraqom basin through the dual lenses of water resource utilization and land subsidence dynamics.MethodologyThe study employed the Inverse Distance Weighting (IDW) method in GIS 10.8 to create zonation maps for three critical groundwater indices: electrical conductivity (EC), sodium adsorption ratio (SAR), and groundwater level decline. Data from 273 observation wells (2001-2018) were classified into four desertification intensity categories (low, moderate, severe, and very severe). These maps were integrated with a land subsidence rate map (2015-2016 water year) derived from Sentinel-1 satellite imagery provided by the Geological Survey of Iran. Additionally, reservoir volume changes (1985-2018) were analyzed for each aquifer to assess their relationship with subsidence patterns.ResultsAnalysis revealed severe to very severe desertification across 46.6% of the basin based on EC values, while SAR indicated low degradation in 90.6% of the area. Groundwater depletion showed the most critical conditions, with 53.4% of the basin experiencing severe to very severe impacts, particularly in the Sarakhs, Fariman-Torbat Jam, southwest Mashhad, and Narimani aquifers. Subsidence rates reached severe levels in 18.1% of the basin, with maximum values observed in the Mashhad, Fariman-Torbat Jam, Taybad, and Karat aquifers. The Mashhad aquifer demonstrated the highest subsidence rates and the most significant reservoir volume changes. Integrated assessment of groundwater and subsidence criteria classified 55.9% of the Qara Qom watershed as moderately affected and 26.1% as low-intensity desertification.ConclusionAs agriculture represents the dominant water consumer in the basin, immediate implementation of water efficiency and productivity measures in this sector is crucial to prevent irreversible socio-economic and ecological consequences of ongoing desertification and land degradation.
samira Zandifar; Adeleh Jamalian; Farhad Khaksarian; Hamidreza Abbasi; Mohammadreza Forudi Jahromi
Volume 32, Issue 1 , May 2025, , Pages 50-70
Abstract
Background and ObjectivesGeochemical analyses provide valuable insights into sediment origin, transport mechanisms, weathering processes, sedimentary environments, and tectonic conditions. Identifying the sources of wind deposits and lake sediments is crucial for reconstructing environmental disturbances, ...
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Background and ObjectivesGeochemical analyses provide valuable insights into sediment origin, transport mechanisms, weathering processes, sedimentary environments, and tectonic conditions. Identifying the sources of wind deposits and lake sediments is crucial for reconstructing environmental disturbances, assessing dust storm frequency, and understanding long-term landscape evolution. This study investigates the geochemical composition, sediment dynamics, and provenance of wind deposits in the Hamoun Sistan wetland, southeastern Iran, through geochemical analysis.MethodologyA total of 20 surface sediment samples (0–30 cm depth) were collected based on geomorphological units and topographic maps. Samples were pulverized to 64 µm for analysis. Major oxide percentages and trace element concentrations were determined using a Philips PW2400 XRF (Rh-tube, accuracy: 0.01 wt%) and ICP-MS at the Binaloud Mines Laboratory (Tehran University Science and Technology Park). Data were normalized against the upper continental crust for comparison. Samples S1–S7 were collected from the southern basin, while S8–S20 were from the northern basin. The Ni/Sr ratio cumulative distribution diagram was used for classification, and multivariate clustering was performed using multi-resolution graph-based clustering (MRGC), an unsupervised method suitable for spatially undefined datasets.ResultsSediments in the southern basin exhibit higher concentrations of detrital particles (quartz, fine-grained mica, and carbonates), supported by a strong correlation (R² = 0.77) between SiO₂ and Al₂O₃, indicating aluminosilicate dominance. In contrast, northern samples show elevated MgO, CaO, and Na₂O levels, suggesting mafic/ultramafic source rocks, along with high Fe₂O₃ concentrations indicative of iron-bearing minerals (e.g., biotite, amphibole).Northern sediments, rich in quartz, feldspar, and mica, align with intermediate igneous rock compositions, implying an igneous origin. Southern samples, dominated by quartz and feldspar, reflect sedimentary recycling and higher maturity (classified as arenites), whereas northern sediments are greywackes.Trace element analysis reveals greater enrichment of Rb, Ba, and Sr in northern samples, while high-field-strength elements (Th, U, Hf, Zr) remain immobile. Lower Ni, Cr, and V concentrations in southern samples indicate minimal mafic influence, supported by higher LREE/HREE ratios, consistent with felsic-rich sources.Tectonic discrimination places northern sediments in an active continental margin setting, while southern samples exhibit transitional active-passive margin characteristics.ConclusionGeochemical and petrographic analyses reveal distinct sediment provenances for the northern and southern Hamoun wetlands. Northern sediments derive from erosion of eastern Afghan Hamoun Basin rocks (active margin), whereas southern sediments originate from western passive margin sources. These findings highlight the wetland’s complex sedimentological history and provide a basis for future soil erosion and dust storm management.
Mohammad Khosroshahi; Zahra Saeedifar; Khosro Shahbazi; Samira Zandifar; Sakineh Lotfinasabasl; Azadeh Gohardoust; Fatemeh Dargahian; Maryam Naeemi; Tahereh Ensafi Moghadam; Leila Kashi Zenouzi; Zohreh Ebrahimi Khosefi; Morteza Khodagholi
Volume 30, Issue 4 , February 2024, , Pages 521-541
Abstract
Background and objectivesWind erosion and dust phenomenon are considered as one of the important processes of land degradation and a serious challenge in Iran. This phenomenon occurs due to the interaction between weather and terrestrial processes. The purpose of this research is to investigate and analyze ...
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Background and objectivesWind erosion and dust phenomenon are considered as one of the important processes of land degradation and a serious challenge in Iran. This phenomenon occurs due to the interaction between weather and terrestrial processes. The purpose of this research is to investigate and analyze the trend of temporal and spatial changes in the number of dusty days in Iran and to investigate the role of climate in its spread. MethodologyIn this research, after receiving hourly and daily statistics of dust events (through 148 synoptic and climatology stations) and parameters of precipitation, evaporation, temperature as key climatic elements (from 171 stations) in 22 provinces located in arid and semi-arid regions of Iran, The spread of dust was investigated and the correlation between climate and dust was determined. After calculating the number of dust days in Iran, the information was called in the GIS environment and a map of the spatial changes of the parameter of the number of dust days in the three decades of 1987-1996, 1997-2006, 2007-2016 was prepared. In the following, the spatial analysis of this parameter and its expansion over three decades were investigated. Next, the climate parameter that had the highest correlation with the number of dusty days was selected and after preparing a map of its spatial changes in the GIS software environment, the spatial compatibility of the desired parameter with the expansion of the number of dusty days was investigated. In the next step, after performing the homogeneity test on the dust occurrences, the partial square regression model was used to determine the contribution of the three mentioned climatic elements as independent variables and the number of dust days as a dependent variable. ResultsThe results showed that the number of dusty days and the area of its occurrence have increased in Iran, so that in the last decade under study (2007-2016) compared to the previous two decades, the dustiest event occurred in Iran. This increase has been more intense especially in the western and southwestern regions of the country, which were also affected by extra-local dust events. These dust events have spread to the central regions of the country with greater frequency. The homogeneity test in many provinces showed a common change point (year 2007-2008) in the number of dusty days, which could be related to the beginning of severe droughts and climate changes from this year in Iran. The study of climatic parameters (temperature, precipitation and evaporation) on changes in the number of dust days in Iran showed that during recent years, temperature had the highest significant correlation level (0.58) with the occurrence of dust. The temperature gradient map in the last decade (2007-2016) compared to the previous decade (1997-2006) also showed the increasing trend of temperature, especially in the western and southwestern regions as well as the southeastern regions of Iran. Modeling the effect of climatic parameters of temperature, precipitation and evaporation on the parameter of the number of dusty days showed that the contribution of the studied climatic parameters to the occurrence of dusty days is about 33% and other effects can be related to things such as human factors or soil characteristics, type of vegetation, solar radiation, etc. ConclusionIn general, the results of examining the trend of changes in the number of dust days and climatic indicators for nearly 3 decades indicate a significant increase in the number of dust days in most parts of Iran and the conditions for this increase have been provided and if the trend of changing these indicators in the coming years is according to the current trend, the risk of environmental problems in the country can be expected to increase.