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 objectives
Land 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 objectives
Land 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.
Methodology
The 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.
Results
Analysis 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.
Conclusion
As 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.
Moslem Yazdani; Hamidreza Azimzadeh; Hamidreza Karimzadeh; Mohsen Soleimani
Volume 32, Issue 1 , May 2025, Pages 18-34
Abstract
Background and Objectives
Accurate measurement of wind erosion and dust intensity requires precise sediment traps. However, traps with varying geometric and aerodynamic properties differ in their efficiency for collecting, retaining, and selecting wind-blown particles. This study evaluates the collection ...
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Background and Objectives
Accurate measurement of wind erosion and dust intensity requires precise sediment traps. However, traps with varying geometric and aerodynamic properties differ in their efficiency for collecting, retaining, and selecting wind-blown particles. This study evaluates the collection efficiency, retention capacity, and particle selectivity of two widely used wind erosion sediment traps—the Cox Sand Catcher (CSC) and the Modified Wilson and Cooke (MWAC)—in Iran, where they have recently been implemented for wind erosion monitoring.
Methodology
Tests were conducted using soils from two wind erosion hotspots in Iran: God-e-Govar (Bafq) and Gavkhuni (Sajzi). A suction-type wind tunnel was equipped with custom-designed bases for the traps and soil trays. Experiments were performed in a controlled laboratory setting at wind speeds of 6.1, 7.88, 9.35, and 10.62 m/s. Collection efficiency, retention capacity, and particle selectivity were measured for both traps.
Results
For loamy sand soil, the CSC trap’s collection efficiency at wind speeds of 6.1, 7.88, 9.35, and 10.62 m/s was 20.61 ± 1.11%, 43.06 ± 2.47%, 35.90 ± 5.12%, and 29.41 ± 1.78%, respectively. For sandy soil from Bafq, efficiencies were 25.35 ± 3.35%, 47.33 ± 4.00%, 41.68 ± 5.19%, and 33.11 ± 3.83%. In contrast, the MWAC trap’s efficiencies for loamy sand were 29.75 ± 4.02%, 31.95 ± 7.18%, 57.57 ± 5.21%, and 62.84 ± 5.82%, and for sandy soil, 43.92 ± 8.83%, 44.23 ± 4.34%, and 47.19 ± 2.97% at the respective wind speeds. Both traps exhibited retention efficiencies exceeding 95% for both soil textures. Selectivity was lower for very fine particles (<100 µm) and very coarse particles (>1 mm), but the CSC trap showed greater selectivity for sand particles due to its design.
Conclusion
The MWAC trap’s collection efficiency increased with wind speed for both loamy sand and sandy soils, whereas the CSC trap’s efficiency peaked at approximately 8 m/s before declining. These differences stem from the traps’ geometric and aerodynamic designs. Both traps showed reduced selectivity for very fine (<100 µm) and very coarse (>1 mm) particles, with the CSC trap being more selective for sand particles. Collection efficiency, retention, and selectivity depend on soil particle size distribution, wind speed, and trap design.
Sedigheh Zarekia; Ali Ashraf Jafari; Niloofar Zare
Volume 32, Issue 1 , May 2025, Pages 35-49
Abstract
Background and Objectives
The degradation of rangelands in Iran, characterized by the decline of palatable species and proliferation of invasive plants, coupled with the abandonment of rainfed agricultural lands due to reduced productivity, has significantly compromised forage production for livestock. ...
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Background and Objectives
The degradation of rangelands in Iran, characterized by the decline of palatable species and proliferation of invasive plants, coupled with the abandonment of rainfed agricultural lands due to reduced productivity, has significantly compromised forage production for livestock. As various species of Astragalus serve as crucial forage resources, this study evaluated the efficacy of two establishment methods - direct seeding and transplanting - for five perennial Astragalus species (A. vegetus, A. brachyodontus, A. effusus, A. cyclophyllon, and A. brevidens) at the Homand Abasard research station.
Methodology
The experiment employed a completely randomized block design with three replications for both establishment methods. Direct seeding was conducted in November 2018 using a rainfed system with specific spatial arrangements (6m rows, 0.5m between populations, 0.75m between species, and 25cm plant spacing). Transplanting followed in April 2019 with identical spacing but received two supplemental irrigations for establishment. Data collection occurred in June-July 2021 (two years post-establishment), measuring forage production, canopy cover, plant height, and seed yield. Statistical analysis included ANOVA and Duncan's multiple range test.
Results
Both establishment methods revealed significant interspecific differences (p<0.05) across all measured parameters. Direct seeding outperformed transplanting for all species, with A. effusus achieving superior forage yield (102 g/plant) and A. brevidens showing the highest seed production (14 g/plant) in this method. Transplanted specimens demonstrated reduced performance, with maximum forage (80 g/plant) and seed yields (11 g/plant) recorded for A. brevidens and A. effusus, respectively. Following A. brevidens, A. vegetus and A. effusus exhibited the most favorable overall performance.
Conclusion
Direct seeding proved more effective for Astragalus establishment under conditions of >300 mm annual rainfall with favorable distribution. However, transplanting remains viable where direct seeding is impractical due to seed shortages, poor seedbed conditions, or erratic precipitation. To ensure successful stand establishment, a two-year grazing moratorium is recommended post-planting regardless of establishment method.
samira Zandifar; Adeleh Jamalian; Farhad Khaksarian; Hamidreza Abbasi; Mohammadreza Forudi Jahromi
Volume 32, Issue 1 , May 2025, Pages 50-70
Abstract
Background and Objectives
Geochemical 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 Objectives
Geochemical 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.
Methodology
A 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.
Results
Sediments 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.
Conclusion
Geochemical 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.
Shafagh Rastegar; Fatemeh Shafiee
Volume 32, Issue 1 , May 2025, Pages 71-90
Abstract
Background and Objectives
Ecotourism represents a sustainable income source for rangelands beyond traditional livestock grazing, potentially reducing pressure on these ecosystems by diversifying local livelihoods. While offering economic opportunities and environmental protection benefits, ecotourism ...
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Background and Objectives
Ecotourism represents a sustainable income source for rangelands beyond traditional livestock grazing, potentially reducing pressure on these ecosystems by diversifying local livelihoods. While offering economic opportunities and environmental protection benefits, ecotourism development must balance socioeconomic and ecological considerations. This study evaluates the multidimensional impacts of ecotourism on local communities in Mazandaran province's summer rangelands, focusing on sustainability across economic, social, and environmental dimensions.
Methodology
The study area comprised 120 Range Sites (RS) and 40 villages, with 12 high-tourism RS selected from Paband, Kelia, Sarkh Griveh, Yanesar, and Sankruj villages based on their natural/cultural attractions. Data collection involved validated questionnaires (Cronbach's α = 0.82), interviews, and field observations. The questionnaire assessed nine social, seven economic, and eight environmental impact statements. Statistical analyses included Descriptive statistics (frequency, mean, SD), Kolmogorov-Smirnov test for normality, Friedman test for item ranking, Spearman/Kendall Tau-b tests for correlations, Regression and path analysis (SPSS v26) to model relationships between ecotourism impacts (independent variables) and sustainable livelihoods (dependent variable).
Results
Path analysis revealed that economic factors exerted the strongest direct influence on livelihood sustainability (β=0.385), primarily through income generation (25-30% increases) and seasonal employment creation (15-20 jobs/village), while social factors demonstrated both direct (β=0.106) and indirect economic-mediated effects (β=0.120), significantly improving quality of life (65% of respondents) and cultural preservation. Environmental awareness showed a positive but limited impact (β=0.072), with 55% of locals reporting increased ecological knowledge, though infrastructure development displayed the weakest correlation (r=0.12). Individual characteristics (education, residency) emerged as significant moderators (p<0.01), collectively explaining 69% of livelihood sustainability variance (R²=0.69), whereas ecotourism's effect on migration reduction remained marginal (5% decrease) due to persistent infrastructure gaps (only 30% village adequacy) and awareness deficiencies (40% knowledge gaps).
Conclusion
While ecotourism enhanced socioeconomic conditions (notably incomes and cultural preservation), its potential remains underdeveloped due to:
Infrastructure gaps (only 30% of villages had adequate facilities)
Limited community awareness (40% lacked ecotourism knowledge)
Minimal impact on migration rates (5% reduction observed).
Prioritizing infrastructure investment and implementing integrated ecotourism management plans are critical to maximizing benefits.
Zahra Abbasnasab; navazollah moradi; Yahya Esmaeilpour; Hamid Gholami; Mehdi Biniaz
Volume 32, Issue 1 , May 2025, Pages 91-107
Abstract
Background and Objectives
Applying organic and eco-friendly additives for soil protection and wind erosion control offers an economical and practical solution. Among these, nanoparticles have emerged as an effective soil stabilization method. Chitosan, a natural, non-toxic, and biodegradable polymer, ...
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Background and Objectives
Applying organic and eco-friendly additives for soil protection and wind erosion control offers an economical and practical solution. Among these, nanoparticles have emerged as an effective soil stabilization method. Chitosan, a natural, non-toxic, and biodegradable polymer, shows promise for mitigating wind erosion, and its composites have attracted considerable research interest. In Iran, large quantities of agricultural waste are generated daily, and their uncontrolled release into the environment not only represents a waste of resources but also contributes to pollution. Converting this waste into biochar presents an optimal strategy for enhancing environmental protection. This study evaluates the efficacy of four bio-amendments: (1) nanobiochar from palm tree stems (NBS), (2) nanobiochar from date palm kernels (NBK), (3) a chitosan-biochar composite from palm stems (ComS), and (4) a chitosan-biochar composite from date kernels (ComK), applied at three levels (0%, 1%, and 2% by weight). Their effects on key soil aggregate stability indicators were assessed.
Materials and Methods
Four amendment materials were produced: nano-biochar from palm stems, nano-biochar from date kernels, chitosan-nano-biochar stem composite (ComS), and chitosan-date kernel composite (ComK). Palm biomass residues (stems and kernels) were collected from Minab villages and ground and pyrolyzed at 300–350°C for 3.5 hours. The resulting biochar was converted into nano-biochar using a planetary ball mill. Chitosan was extracted from shrimp shells obtained from Bandar Tiab’s shrimp farms. The chitosan-nano-biochar composite was synthesized using acetic acid and NaOH solutions in laboratory conditions at Hormozgan University. For the experiment, each amendment was mixed with sandy soil at 0%, 1%, and 2% (w/w) in a completely randomized design with three replicates. The treated soils were maintained in plastic pots under greenhouse conditions (field capacity and 50% moisture) for 90 days. Post-incubation, soil samples were analyzed for physical and chemical properties at Hormozgan University’s Soil and Water Laboratory. Data were analyzed using R software (v3.2.2), with mean comparisons performed via Tukey’s HSD test (p < 0.05), and graphs were plotted in Excel.
Results
The study utilized a sandy-textured soil with near-neutral pH and salinity (15.04 dS/m), where date kernels showed higher carbon and volatile content but lower moisture and ash compared to palm stems. All amendment materials significantly (p < 0.05) improved soil properties, though effects varied by material type and application rate. Specifically, all treatments increased soil pH, aggregate stability, mean weight diameter (MWD) of dry aggregates, and clay-silt dispersion ratio while reducing bulk density and electrical conductivity (EC). Date kernel-derived amendments (NBK, ComK) at higher application rates (2%) were particularly effective, decreasing EC by 18-22% and bulk density by 12-15% while increasing aggregate stability by 30-35% and MWD by 25-28%. In contrast, palm stem-derived amendments (NBS, ComS) showed mixed effects - while increasing MWD by 15-18%, they reduced aggregate stability by 8-10% and increased bulk density by 5-7% at higher application rates. The chitosan-biochar composites demonstrated superior performance compared to nano-biochar alone, with ComK showing the most balanced improvement across all measured parameters. These findings confirm that both nanoscale amendments and organic polymers can effectively modify the physical and chemical properties of erosion-prone soils, with material source and application rate being critical factors determining their efficacy.
Conclusion
All tested amendments enhanced soil quality, underscoring their potential for wind erosion mitigation. Improving soil physicochemical properties is critical for sustainable land management and dust storm control. Implementing technical and management strategies to optimize these amendments could significantly reduce wind erosion, addressing the pressing challenge of dust storms.