Volume 27, Issue 3 , October 2020
Parvaneh Ashouri; Behnam Hamzeh; Adel Jalili
Volume 27, Issue 3 , October 2020, Pages 385-395
Abstract
The ecological model of productivity-species richness relationships states that maximum species diversity occurs when species production is moderate, and there is a humped-back pattern between production as ecosystem energy variable and species richness. The discovery of this ...
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The ecological model of productivity-species richness relationships states that maximum species diversity occurs when species production is moderate, and there is a humped-back pattern between production as ecosystem energy variable and species richness. The discovery of this relationship leads to an understanding of the processes of biodiversity formation in ecosystems. To test this model, species production and richness were measured in the semi-steppe ecosystem of Gharebough in the Anguaran wildlife refuge in Zanjan province. Correlation and linear and nonlinear regression analysis were used to examine the relationship between species richness as a dependent variable and productivity as an independent variable. A total of 41 plant species were identified in 30 plots. The average species richness per plot per square meter was calculated as nine species. The relative production percentages were 15% for shrubs, 16% for forbs, and 69% for grasses. The highest percentage of presence in the plots was allocated to Stipa lessingiana, Poa bulbosa, Astragalus stevenianus, and Bromus tomentellus. The total production of the species was calculated to be 83 g/m2. Shrub production and forbs showed a significant linear regression relationship with species richness. Also, the shrub production had a significant nonlinear regression relationship with species richness, showing a humped-back pattern. The findings of this study showed that increasing production increases species richness and according to the values of the coefficient of explanation of regression relations (R2), in addition to the production factor, other important factors play a role in species richness. Therefore, this hypothesis cannot be confirmed on a local scale.
Mahshid Souri; mirfarhad blurfrush; Hirad Aghbari; javad motamedi; Behnaz Attaeian
Volume 27, Issue 3 , October 2020, Pages 369-409
Abstract
If the rangeland forage is used continuously, the important elements such as NPC do not return to the soil, which will cause the rangeland lands to lose their fertility. Therefore, nowadays, in the field of rangeland management, rangeland improvement and rehabilitation has become ...
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If the rangeland forage is used continuously, the important elements such as NPC do not return to the soil, which will cause the rangeland lands to lose their fertility. Therefore, nowadays, in the field of rangeland management, rangeland improvement and rehabilitation has become very important. The use of fertilizers is one of the methods to rehabilitation the rangelands. If the proper fertilizer application is carried out in accordance with the climatic conditions, cover condition, and soil characteristics, it will improve the rangeland. Otherwise, it will increase the concentration of salts, soil toxicity, and surface and groundwater contamination and leads to drying of the plants. The aim of this study is to present a model based on the use of an artificial neural network that expresses the relationships between organic carbon, nitrogen and phosphorus of rangeland soil and plant factors, based on which, it is possible to estimate the mentioned elements in the rangeland ecosystems without statistics to manage fertilization. Based on the results, organic carbon, nitrogen and phosphorus of the soil were estimated in the Nazlocha rangeland of Urmia. Eight factors of electrical conductivity, acidity, clay percentage, silt percentage, sand percentage, lime content, production and canopy cover percentage of rangeland plants were also selected for factor analysis. Therefore, according to the mentioned results, the neural network was able to accurately predict the amount of organic carbon, nitrogen and phosphorus in rangeland soils. According to the results, the vegetation type Astragalus gummifera-prangos uloptera-Bromus tomentellus requires phosphorus and nitrogen fertilizers. Onobrychis cornuta- Festuca ovina-Thymus kotschyanus requires phosphorus fertilizer, and Astragalus macrostachys-Noeae mucronata-Stipa barbata requires organic matter and nitrogen and phosphorus fertilizers.
Bayazid Yousefi; Jamal Hassani; Mohammad Fayaz
Volume 27, Issue 3 , October 2020, Pages 410-420
Abstract
This study was aimed at investigating the effects of planting time and method on the establishment and production of Onobrychis subnitens (sainfoin) in rainfed conditions of Saral research station (365 mm annual rainfall) in Sanandaj (Kurdistan-Iran) during 2013 -2016. ...
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This study was aimed at investigating the effects of planting time and method on the establishment and production of Onobrychis subnitens (sainfoin) in rainfed conditions of Saral research station (365 mm annual rainfall) in Sanandaj (Kurdistan-Iran) during 2013 -2016. Two planting times (spring and fall) and methods (line sowing and seeding) were studied in a split-plot design based on the randomized complete block design in three replications. The results showed that in the third year of cultivation, the average percentage of plant establishment in the plot was 53%, the average canopy cover of the plot was 45.4%, and the average fresh and dry forage yield of the plot (8 m2) were 5268.5 (6585.6 kg ha-1) and 2831.5 g (3539.4 kg ha-1), respectively. Traits of plant establishment percentage, plant density, average canopy cover, dry and fresh forage yield showed a significant difference (p < /em>≤0.05) between fall and spring sowing; however, the difference between line sowing and seeding methods and the interaction effects of time and planting method was not significant for the traits studied. The forage yield showed a significant positive correlation with plant height, plant weight, main stem number per plant, plot green cover percentage, plant vigor rate, and dry to fresh weight ratio of forage (p≤0.01), and also a significant positive correlation with plant density in plot and average plant canopy diameter (p≤0.05). Based on the results of the regression of forage yield as an independent variable on other traits, the plant fresh weight, plant height, and established plants percentage in the plot showed the highest contributions in the forage yield. This result indicates the high and direct impact of these traits as the main components of forage yield. In general, considering the relative superiority of plant establishment percentage and average forage yield in fall planting and line sowing method compared to spring sowing and seeding method, as the final result, fall seeding of this species in Sanandaj and similar areas is recommended.
Ali Yazdanpanahi; Khaled Ahmadaali; Mohammad Jafari; Salman Zare
Volume 27, Issue 3 , October 2020, Pages 421-432
Abstract
Nowadays, the addition of bio-charcoal to soils, as a way for carbon sequestration in the soil, reducing the concentration of carbon dioxide in the air, improving soil fertility, and reducing wind erosion, has attracted much attention. The aim of this study was to investigate ...
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Nowadays, the addition of bio-charcoal to soils, as a way for carbon sequestration in the soil, reducing the concentration of carbon dioxide in the air, improving soil fertility, and reducing wind erosion, has attracted much attention. The aim of this study was to investigate the effect of biochar application on yield and components of Haloxylon species in a randomized complete block design with soil additive factors including mycorrhizal fungi at two levels (consumption of 50 g of mycorrhiza and non-consumption of mycorrhiza), natural charcoal, and biochar produced from municipal waste compost at four levels (0, 50, 150 and 250 g / kg soil of dry soil), in the greenhouse of the Agriculture and Natural Resources, University of Tehran for nine months. The results showed that the addition of biochar had no significant effect on any of the morphological characteristics of Haloxylon persicum except root surface. The results also indicated that the average collar diameter, height, root area, fresh and dry weight of Haloxylon aerial parts in mycorrhiza-free treatments increased 31.9%, 35.7%, 15.5%, 56.9%, and 32.6%, respectively, and in mycorrhiza treatments, these characteristics increased by 4.7, 16.1, 11.1, 33.4, and 6.7%, respectively, as compared to the control treatment. Among the treatments studied, treatment nine (soil + 150 g natural charcoal + 250 g municipal waste compost) had the most positive effect on the morphological characteristics of Haloxylon.
sahar ghafari; Ardavan Ghorbani; mehdi moammeri; Raoof Mostafazadeh; Mahmoud Bidar Lord; azad Kake mami
Volume 27, Issue 3 , October 2020, Pages 433-462
Abstract
The aim of this study was to predict the habitat expansion of Festuca ovina by maximum entropy method and to determine the effective factors on its spread in the elevation gradient of Moghan-Sabalan rangelands of Ardabil province. The 28 study sites were selected and in each study site 3 transects and ...
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The aim of this study was to predict the habitat expansion of Festuca ovina by maximum entropy method and to determine the effective factors on its spread in the elevation gradient of Moghan-Sabalan rangelands of Ardabil province. The 28 study sites were selected and in each study site 3 transects and along each 100-meter transect 10 plots of 1 1m2 with a distance of 10 meters from each other were selected for sampling. Soil sampling in each study site was sampled from two depths of 0-15 and 15-30 cm. Soil properties using spatial statistics, topographic characteristics using digital elevation model, climatic information using meteorological data of the region, and land use measurements prepared with the help of a user map. Prediction maps related to the distribution of F.ovina were prepared using the maximum entropy modeling method. The role of environmental factors affecting the distribution of the species was investigated using the Jackknife method and response curves. Height variables, slope, patch size (coefficient of variation), potassium (15-30 cm depth), and lime (0-15cm depth) had the highest share in the model. The area under the curve index (AUC) was 0.86, which indicates the accuracy and average efficiency of the model in identifying the most desirable distribution areas. The kappa coefficient obtained from the comparison of forecast and actual maps was 0.72, which is at a very good level.
Leila Bakhshandehmehr; Mohammadreza Yazdani; Reza Jafari; Saeid Soltani
Volume 27, Issue 3 , October 2020, Pages 463-484
Abstract
Research on the environmental controllers in plant communities is one of the research fields for many ecologists. Identifying the factors affecting the vegetation cover in the arid regions is the first step to recognize the destructive factors, which inhibit the growth and development of vegetation. ...
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Research on the environmental controllers in plant communities is one of the research fields for many ecologists. Identifying the factors affecting the vegetation cover in the arid regions is the first step to recognize the destructive factors, which inhibit the growth and development of vegetation. In the current study, using the structural equation modeling method and Partial Least Square – Structural Equation Modeling (PLS-SEM), climatic and pedological variables that affecting the vegetation cover in steppe rangelands of Zayandehrood basin of Isfahan province were identified and modeled. According to the results, soil clay content, maximum runoff height on the soil, temperature, and dryness of the environment are the most important variables affecting the quantity and quality of vegetation in the rangelands of the Zayandehrud basin. Besides, the role of climatic factors is more than soil factors in the distribution of vegetation in the region. The model presented in this research has good accuracy and high flexibility for modeling ecological phenomena.
Mohammad Amin Soltanipoor; Ehsan Zandi Esfahan
Volume 27, Issue 3 , October 2020, Pages 485-494
Abstract
Utilization of saline lands with the aim of producing lignocellulosic biomass, which has no nutritional value and can be converted to ethanol and at the same time has no effect on human food production, seems necessary. Halophytes and salt-tolerant plants that produce high biomass using saline resources ...
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Utilization of saline lands with the aim of producing lignocellulosic biomass, which has no nutritional value and can be converted to ethanol and at the same time has no effect on human food production, seems necessary. Halophytes and salt-tolerant plants that produce high biomass using saline resources (saline water and soil) can be considered as an important alternative in this regard. For this purpose, this study with the aim of investigation of ethanol producing potential of five species of Auluropus lagopoides, Atriplex leucoclada, Desmostachya bipinata, Halopyrum mucronatum and Halocnemum strobilaceum was conducted in Hormozgan province in 2016. Plant samples were collected at three phenological (vegetative, flowering and seeding) stages from two saline lands in Zaminsang and Sirik, Hormozgan province and three parameters of lignin, hemicellulose and cellulose were measured. Data analysis of variance was performed as a factorial experiment based on the completely randomized design with three replications and comparison of means with Duncan's multiple range test in SPSS-14 software. The results showed that Halopyrum mucronatum had the potential to produce ethanol in all three vegetative stages. Halocnemum strobilaceum had the potential for ethanol production only at the vegetative growth stage and Aeluropus lagopoides and Desmostachya bipinata had the potential for ethanol production only at the seed ripening stage.
Mohammad Abolghasemiy; Sedigheh Zarekia; seyyed Mojtaba Safavi
Volume 27, Issue 3 , October 2020, Pages 495-503
Abstract
A significant area of the country's rangelands has been destroyed by various factors such as uncontrolled exploitation, climate change, and other factors. An important part of the rangeland plants has been endangered, and the abundance of some important plant species has been ...
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A significant area of the country's rangelands has been destroyed by various factors such as uncontrolled exploitation, climate change, and other factors. An important part of the rangeland plants has been endangered, and the abundance of some important plant species has been severely reduced. To create stability in such rangelands, their improvement and rehabilitation by selecting suitable species and finding the best cultivation and establishment methods have a special priority. For this purpose, the seeds of the most important populations of perennial plants and forages, along with their existing populations, were collected from the rangelands of different regions of Yazd and South Khorasan provinces on appropriate dates. The study was conductedin the form of a randomized complete block design with three replications in the field conditions, and the characteristics of forage production yield, canopy cover percentage, height, and seed yield were recorded. Data were analyzed using SAS software, and the means were compared with the Duncan test. The results showed that the populations of Kharanagh, (production 1094 g per plant and canopy cover 10548 cm2) Tabas (production 1734 g per plant and canopy cover 17221 cm2) Halothamnus subaphyllus and Tabas population of Salsola imbricata (production 2278 g per plant and canopy cover 22221 cm2) and Bahabad population of Salsola yazdiana (production 530 g per plant and canopy cover 4646 cm2) were superior in terms of the evaluated traits compared to other populations that could be taken into account for the improvement of saline rangelands.
Sajad Amiri; qasem khodahami
Volume 27, Issue 3 , October 2020, Pages 504-515
Abstract
Three perennial grass species, Stipaarabica, Elymus pertenuis, and Hordeum bulbosum, were selected in the semi-steppe habitats of Fars province, and seeds of 15 populations of these three species (5 species of each genus) in were collected 12 habitats. For each population, 120 pots (a total of 1800 pots) ...
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Three perennial grass species, Stipaarabica, Elymus pertenuis, and Hordeum bulbosum, were selected in the semi-steppe habitats of Fars province, and seeds of 15 populations of these three species (5 species of each genus) in were collected 12 habitats. For each population, 120 pots (a total of 1800 pots) were prepared and the seeds (three seeds per pot) were planted. In the third year, after preparing the main land, seeds were planted in three rows in each plot based on a completely randomized block design. Necessary evaluations after emergence of the species were performed based on the cover canopy area, plant height, forage production, seed production, and vigor. The results showed that Hordeum bulbosum with seed production of 471.67 kg and forage production of 539.20 kg/ha had the highest production, and Stipa arabica had the highest canopy cover (1642 cm2) and vigor (92.60%). Elymus pertenius had the highest forage production (460.93 kg/ha) and canopy cover (1447 cm2).
Tahereh Ensafi moghaddam
Volume 27, Issue 3 , October 2020, Pages 516-544
Abstract
In the present study, the Miqan sub-basin of the Arak region was quantitatively investigated to find out the temporal and spatial variations of groundwater level in the nine Qanats (subterranean canals). The methodology to evaluate the spatial and temporal changes of groundwater level, the ...
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In the present study, the Miqan sub-basin of the Arak region was quantitatively investigated to find out the temporal and spatial variations of groundwater level in the nine Qanats (subterranean canals). The methodology to evaluate the spatial and temporal changes of groundwater level, the 26 years data of changes in underground water (1365 -1390) produced by the Water Authority Bureau of Arak city for the Miqan-sub-catchment were collected and analyzed using GIS software and time series methodology processing of data. In this methodology, firstly the mean of water discharge and withdrawals of qanats water for daily, monthly and annually were analyzed and monitored. Then the trend of changes in the water level of all investigated wells for the 26 years data was graphically determined for those time series respectively. Secondly, a group of hydrograph for this sub-catchment were presented in figures and compared for all-time series based on daily, monthly, seasonally and annually respectively mentioned in the paper. Linear regression (simple linear) and Mann-Kendall statistics method were used to test the significant trend of changes in the underground level for all the periods' mentioned above. In the last stage, to produce the sub-catchment maps for showing the groundwater hydrograph of the plain, interpolation on maps was performed using ARC GIS software. The results indicated that according to the hydrograph of the 26 years of groundwater level has decreased drastically. Available hydrogeological data also show a sharp drop in aquifer water levels in recent years. The maximum rate of decline has been observed in the central parts, located below the Miqan basin. The most important reasons in increasing the rate of groundwater level are the mismanagement and uncontrolled withdrawal of groundwater resources by resident farmers and also the frequent reduction of precipitation
Maryyam Molaei; Ardavan Ghorbani; Mehdi Moameri; Asgar Hossainzadeh
Volume 27, Issue 3 , October 2020, Pages 545-560
Abstract
The purpose of this research was to model the spatial distribution of Artemisia fragrans and A. chamaemelifolia in Ghezelozen-Aghdagh elevation profile rangelands of Khalkhal city. For modeling, information about species and habitat factors such as topography, soil, and climatic factors ...
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The purpose of this research was to model the spatial distribution of Artemisia fragrans and A. chamaemelifolia in Ghezelozen-Aghdagh elevation profile rangelands of Khalkhal city. For modeling, information about species and habitat factors such as topography, soil, and climatic factors were used, and habitat distribution modeling was performed by a logistic regression method. All parameters affecting the distribution of species were prepared as a raster map. Then, by combining the maps of the factors affecting the species distribution, the distribution map was predicted through the logistic regression method. The results showed that the most important factor in spatial prediction of A. fragrans in the region was altitude and with each meter of elevation, the presence of this species decreased by 0.88%. The results also showed that the presence of A. chamaemelifolia species was inversely related to altitude, mean temperature, and soil potassium. The Kappa index was used to determine the agreement between the prediction models with ground truth. The kappa coefficient was 0.91 for A.fragrans and 0.62 for A. chamaemelifolia, which indicates the excellent agreement of the model with reality. According to the prepared forecast map, A. fragrans and A. Chamaemelifolia species can be considered for lowland and higher altitude rangelands.
Maliheh Keyghobadi; Hossein Piri Sahragard; Mohammad Reza Pahlavan Rad; Peyman Karami; reza yari
Volume 27, Issue 3 , October 2020, Pages 561-576
Abstract
Species distribution models (SDMs) are the basis of informed decisions in vegetation management by quantifying the relationship between species distribution and influential environmental variables. The present study aimed to evaluate the GAM and CART models' performance in estimating ...
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Species distribution models (SDMs) are the basis of informed decisions in vegetation management by quantifying the relationship between species distribution and influential environmental variables. The present study aimed to evaluate the GAM and CART models' performance in estimating the potential habitat distribution as well as recognizing the ecological needs of plant species in the Khezri rangelands of Bayaz plain of southern Khorasan. According to the regional condition and field observation, in an area of about 14500 hectares, vegetation sampling was done using the randomized-systematic method. Eighteen environmental variables including land characteristics, Normalized Difference Vegetation Index (NDVI), and salinity index were used as an estimator to generate maps of predictor variables. After modeling the habitat distribution prediction using CART and GAM methods in R 3.5.2 software, the accuracy of the models was assessed using the subsurface area (AUC) statistics. After determining the threshold by the TSS method, the continuous utility map was converted to the presence/absence map and the degree of conformity of the maps with the kappa index was calculated. Based on the results of the used models, the variables of the base level of the channels network, the vertical distance to the channels network, the depth of the valley, the wetness index, and the relative position of the slope are effective in habitat suitability for species establishment. In general, the GAM method has high accuracy in estimating the habitat distribution range of all species studied (Kappa≥ 0.9). According to the maps obtained from the GAM model, the highest and lowest potential habitats belong to S. rigida and T. serotina species. Therefore, the GAM method can be useful in accurately identifying the ecological needs of plant species and therefore their distribution useful at the local scale. As a result, it is suggested that this method be used as part of a management support system in the protection and restoration of vegetation in the rangelands of the Bayaz plain.
mohammad ekrami; rasool mahdavi; mazieh rezaei; hassan vagharfard; Jalal Barkhordari
Volume 27, Issue 3 , October 2020, Pages 577-595
Abstract
Drought can reduce the sustainable production of natural ecosystems, including rangelands. The main purpose of this study was to expand the vulnerability of rangelands drought in the Pishkuh watershed in Yazd province. In the present study, geographical information systems ...
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Drought can reduce the sustainable production of natural ecosystems, including rangelands. The main purpose of this study was to expand the vulnerability of rangelands drought in the Pishkuh watershed in Yazd province. In the present study, geographical information systems and multi-criteria decision-making method (AHP) were used. In this regard, the parameters affecting the drought vulnerability of rangelands of the study area, including slope, slope direction, precipitation, soil texture, and evaporation were extracted and converted into information layers with the help of GIS. After weighing the layers in terms of importance in drought vulnerability in the framework of multi-criteria decision making (MCDM), the final combination and drought vulnerability map of the study area was prepared. Also, to control and measure the final map, field studies of the study area were used. Finally, a map of the dominant rangeland vegetation type was prepared and overlapped with the drought vulnerability map of the rangelands of the study area to identify the most resistant and vulnerable rangeland vegetation type. The results showed that the highest weight of the effective parameters in rangeland drought vulnerability was related to the precipitation with a value of 0.54, and the lowest weight was related to the slope with a value of 0.061. Based on the results, the eastern, southeastern, and southern regions of the Pishkuh watershed have the highest rate of rangelands drought vulnerability, and Ar.au-St.ba.Sc.or type is the most vulnerable vegetation type in the study area. It is recommended that more management resources and strategies be implemented in vulnerable rangelands to protect the soil and its vegetation.
Mohsen Armin; Afsaneh Khairi; Vajihe Ghorbannia Kheybari
Volume 27, Issue 3 , October 2020, Pages 596-616
Abstract
Rainwater harvesting is a management technique with many positive results that can be used to supply the water needed by livestock in rangelands. In this study, suitable sites for the construction of rainwater harvesting systems using multi-criteria analysis (MCE) and hydrological ...
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Rainwater harvesting is a management technique with many positive results that can be used to supply the water needed by livestock in rangelands. In this study, suitable sites for the construction of rainwater harvesting systems using multi-criteria analysis (MCE) and hydrological model (HM) in the GIS environment were identified in the nomadic ecology of Ab Bahareh at the interval of Bahmaei and Lendeh counties in Kohgiluyeh and Boyer-Ahmad province. For this purpose, appropriate criteria maps to identify sites of rainwater harvesting system including slope, rock type, land use and land cover, runoff depth, and drainage density were provided in the GIS environment. After classifying the suitability map of each criterion, the classified map of the criteria was overlaid into the geographic information system environment and the appropriate sites for the rainwater harvesting system were identified. The results showed that in terms of each of the selected parameters, except for the slope, about 30 to 50 percent of the Ab Bahareh area was very suitable for the construction of rainwater harvesting systems. Due to the mountainous nature of the region, the slope parameter is the main limitation for the construction of rainwater harvesting systems. Based on the combined analysis of all the criteria selected, about 25% of the nomadic ecosystem of Ab Bahareh is highly suitable for the construction of rainwater harvesting systems, especially pits and ponds, rock outcropping catchment, road catchment, and check dams that can be provided during the dry season between rains. In regard to the number of 4000 goats and sheep in 5 villages in the nomadic ecosystem of Ab Bahareh, assuming the daily requirement of each livestock to 4 liters of water and the dry period of 30 days between the main rains, the total catchment area for the 25 mm rainwater harvesting system to meet the needs of livestock in the region is about 2.4 hectares.
Mahdi Boroughani
Volume 27, Issue 3 , October 2020, Pages 617-631
Abstract
Sistan watershed has caused severe dust storms in the region in recent years due to the drying up of Lake Hamoon and consecutive droughts. This study aimed to identify and determine the characteristics of dust source areas (land use, lithology, slope, and geomorphology) in the ...
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Sistan watershed has caused severe dust storms in the region in recent years due to the drying up of Lake Hamoon and consecutive droughts. This study aimed to identify and determine the characteristics of dust source areas (land use, lithology, slope, and geomorphology) in the Sistan watershed. To identify the dust source area, MODIS satellite images of dust days for the period 2015 to 2019 were used using dust detection indicators including BTD3132, BTD2931, NDDI, and D. The results of identifying dust source area indicate that a total of 211 dust source areas were identified in the whole region. Of these identified dust source area, 61 are in Iran and 150 in Afghanistan. The results of the distribution of dust collection centers in different uses indicate that dryland agricultural lands with 172 centers, dried lake surfaces, and irrigated agricultural lands with 16 and 12 sources have the highest dust collection sources. From the overlap of the lithology map and dust source, it was obtained that the most dust source area with 111 and 98 sources, respectively, are located in continuous and discontinuous sedimentary formations. The results of the distribution of dust source area in geomorphological units indicate that the erosion plain unit with an area of 35.69 percent, 48 dust source area has the highest collection source. Also, the results of the distribution of dust source area in different slopes show that the highest dust source area is in the slopes of 0 to 2% with 107 sources and the lowest located in more slopes of 32%% with 6 sources.