Morteza Abtahi
Volume 28, Issue 4 , November 2021, , Pages 605-613
Abstract
Biological stabilization of dunes is one way to prevent wind erosion and the creation of sandstorms. Clligonum is one of the plant species that due to its unique root structure can settle in the dunes and stabilize them. In this study, we intend to investigate the most suitable species and age of Calligonum ...
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Biological stabilization of dunes is one way to prevent wind erosion and the creation of sandstorms. Clligonum is one of the plant species that due to its unique root structure can settle in the dunes and stabilize them. In this study, we intend to investigate the most suitable species and age of Calligonum shrub for planting in three different points of Kashan long sand. This research is in the form of split-plot (split plots) based on the randomized block design. Analysis of variance showed that the differences between different locations and the age of different seedlings and species of Calligonum were significant at the level of (p≤0.01). In all three age groups, Calligonum turkestanicum with 61.15% had the highest establishment, and C. comosum is in the second rank, and C. schizopterum and C. bungei species were in the third and fourth ranks, respectively. Siazgeh region, with an average of 59.7%, has the highest percentage of seedlings. Three-year seedlings, with an average of 58.7%, had no significant difference with two-year seedlings with an average of 57.01% and with one-year seedlings with an average of 53.84% at the level of (p≤0.01).Accordingly, the use of 0biennial C. turkestanicum seedlings and three-year C. comosum seedlings is recommended for sand stabilization in Kashan region.
Morteza Abtahi
Volume 26, Issue 3 , September 2019, , Pages 517-530
Abstract
Wind erosion and its consequences, such as dust storms and sand movement is one of the environmental problems in arid regions. There are several ways to combat wind erosion, among which biological reclamation using drought-tolerant species and psammophytes is the most sustainable method. The initial ...
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Wind erosion and its consequences, such as dust storms and sand movement is one of the environmental problems in arid regions. There are several ways to combat wind erosion, among which biological reclamation using drought-tolerant species and psammophytes is the most sustainable method. The initial establishment of these plants requires the use of sand stabilizers such as mulches. The mulch used in the past was the product of oil refineries and industries, which despite its merits such as strength and flexibility, had many environmental consequences. Therefore, researchers and scientists in the country decided to present an eco-friendly product that would replace the oil mulch. One of these products is polymer-cellulosic mulch, produced by the Department of Chemistry, Malek Ashtar University of Isfahan. This mulch was used in sand dunes of Kashan, during which the mulch resistance to environmental conditions, its effect on plant establishment, and soil moisture uptake and retention were investigated. The results showed that this mulch had no negative effect on plant establishment. Its resistance to wind erosion is very good for the first few months of spraying. However, over time and during the hot summer months, cracks appear that partially overshadow the mulch's stabilizing properties. The soil moisture content was about 4.5% higher in 10 t/h mulch as compared with control. In general, for the crust and cracks problems, this mulch cannot be a good alternative to petroleum mulch.
Mehdi Farahpour; fatholah Ghayour; Hosein Sharbaf; Ali Yousefizadeh
Volume 12, Issue 2 , September 2019, , Pages 121-134
Hamidreza Abbasi
Volume 8, Issue 3 , September 2019, , Pages 93-112
Hosein Golbabaie; Abolfazl Khalilpour; Alimohammad Tahmasebi Beyragani
Volume 11, Issue 3 , August 2019, , Pages 255-274
Mahsa Abdolshahnejad; Ali Akbar Nazari Samanni; Mehdi Ghorbani; Aziz Orsham; feridoon Taheri
Volume 26, Issue 2 , July 2019, , Pages 325-339
Abstract
The effects of human activities on the land use and landscape and its subsequent effects on the natural environment have always been considered. Therefore, to have a sustainable landscape planning, knowing about such changes would be essential. Satellite images of TM sensor in ...
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The effects of human activities on the land use and landscape and its subsequent effects on the natural environment have always been considered. Therefore, to have a sustainable landscape planning, knowing about such changes would be essential. Satellite images of TM sensor in 1990, ETM+ Sensor in 2002 as well as OLI Landsat 8 in 2013 were used to investigate the trend of changes and preparation of cover maps. The executive phase of the study included the analysis of the gradient of land use structure in eight geographical directions for class area (CA), number of patch (NP), and mean patch size (MPS) in seven classes such as woodland) low-density forest and garden), water zone, agriculture, bare land, rangeland, urban and sand dunes. The results showed that the land use of woodland, urban, and sand dunes had an increasing trend, while the bare land showed a decreasing trend. The results of gradient analysis of land use structure in eight geographical directions indicated that the most changes were in the west and center of the region. Based on the analysis of changes rate of metrics, the most changes were recorded for rangeland, bare land, and urban during 1990 to 2002; the woodland, agriculture, and urban during 2002 to 2013; and rangeland, woodland and urban during 1990 to 2013. Therefore, given that some aspects of land use change depend on human aspects, the relationship between these quantitative indicators can be used to determine the sustainability level as well as the future trend of land use change to identify the critical affected areas. Metrics of area, number of patches and mean patch size were recognized as the important indices in discussions of monitoring land use and mosaic changes.
Zeynab Gandomi; Amir Hosein charkhabi; Hasan Mohseni; Manouchehr Amiri
Volume 24, Issue 4 , January 2018, , Pages 897-906
Abstract
The southwest province of Iran has a dry and semi-arid climate, with about 250,000 hectares of sand dunes; therefore a comprehensive review and overview of these features and their correlation with other features is needed. In this study, over 200 sand samples were collected from the ...
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The southwest province of Iran has a dry and semi-arid climate, with about 250,000 hectares of sand dunes; therefore a comprehensive review and overview of these features and their correlation with other features is needed. In this study, over 200 sand samples were collected from the mobile and not mobile sand dunes to study the grain size of sand dunes in Khuzestan. The results showed there was no significant difference in the mean grain size from east to west, along a 200 km transect of the sampled area. The mean grain size in the west was 2.87 to 2.14 φ scale (136 to 226 microns) and in the east 3.05 to 2.16 φ (120 to 223 microns). The standard deviation of particle size of the samples was good and fairly good (0.71 to 0.35 φ). Using tilt condensation particle diameter in the range of sand dunes area, folk scale (0.1 to 1 φ) was positive. These distances represent 20 to 50 km with mean transported distance of 35 km for the west and 50 to 200 km transported distance with mean value of 125 km for the east section of the Khuzestan province for the sand dunes. For the transport distances, average transport distance could be divided into four categories, including 3, 12.5, 35 and 125 km. According to the results, the source of particles of the sand dunes in Khuzestan province is local, mainly from northwest and west.
farokh asadzadeh; maral khodadadi; ehsan ehsan malahat
Volume 24, Issue 1 , May 2017, , Pages 126-141
Abstract
Huge parts of Urmia Lake have been dried up in recent years. As a result, vast areas of salty fine sand dunes, which are very susceptible to wind erosion, have been formed. This study was conducted to investigate the performance of Particle Size Distribution (PSD) models in description of sand dune PSDs ...
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Huge parts of Urmia Lake have been dried up in recent years. As a result, vast areas of salty fine sand dunes, which are very susceptible to wind erosion, have been formed. This study was conducted to investigate the performance of Particle Size Distribution (PSD) models in description of sand dune PSDs and predicting wind erodibility by using PSD models in parts of western coast of Urmia Lake. Totally, 48 samples from a grid of 500m × 500m were collected. PSD of the samples was determined by dry sieving method. Statistical parameters of grain size including mean, sorting, skewness and kurtosis were calculated. Performance of nine PSD models in describing the grain size distribution was assessed by the coefficient of determination (R2), Root mean square error (RSME) and Akaike criterion (AIC) of the models. To determine wind erodibility of sand dunes, mass fractions of aggregates
Amir Hosein parsamehr; zahra khosrovani
Volume 23, Issue 4 , March 2017, , Pages 832-842
Abstract
In arid and desert regions, wind has an important role in soil erosion. The amount of wind energy and its direction variability have significant control on the morphology and maintenance of aeolian land forms. This research was aimed to analyze the erosive winds and investigate the discharge and sediment ...
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In arid and desert regions, wind has an important role in soil erosion. The amount of wind energy and its direction variability have significant control on the morphology and maintenance of aeolian land forms. This research was aimed to analyze the erosive winds and investigate the discharge and sediment transport in the study area. For this research, anemometric data of a duration period of 20 years (1994-2013) were analyzed. Wind rose and sand rose are one of the best methods to determine the wind erodibility. The results obtained from the analysis of wind rose data indicated that the direction of prevailing wind in the study area was NE, W and E. The results of sand rose for a wind speed threshold of 12 knots showed that the drift direction was from south – west towards north – east. The maximum and minimum amount of total sand drift potential was 105.3 and 594.7 in vector units, related to Kashan and Ardestan stations, respectively.
Marzieh Abassi; Sadaat Feiznia; Hamid reza Abassi; Uones Kazemi; Ahmad Gharanjik
Volume 18, Issue 3 , September 2011, , Pages 441-451
Abstract
Source identification of sand dunes is of particular importance in projects of wind erosion control. In this study, the map of geomorphology and inventory map of sand dunes were prepared for five regions of Baluchestan under wind erosion using aerial photos, satellite images and Arc-View ...
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Source identification of sand dunes is of particular importance in projects of wind erosion control. In this study, the map of geomorphology and inventory map of sand dunes were prepared for five regions of Baluchestan under wind erosion using aerial photos, satellite images and Arc-View and Arc-GIS soft wares. Then, 28 samples were collected based on the form of sand dunes and geomorphological facies. The samples were analyzed for Granulometry, morphoscopy and mineralogy in the laboratory. Granulometric analysis was performed using dry–sieving technique and the curves and statistics were drawn and calculated using Gradistat software. The morphoscopic and mineralogic investigation were performed using binocular microscope. Granulometric analyses show that the sediments are well sorted, having better sorting than fluvial sediments, with standard deviation of less than 0.5. Morphoscopic analyses mostly show the effect of Aeolian transport on the grains. Mineralogical studies show that the most abundant particles in the sediments are rock fragments consisting of limestone, quartzite and granodiorite (%84), and the rest are minerals such as quartz, feldspat and calcite. About 94.5 percent of the particles have been transported in saltation. The results of differentiation of sediments according to sedimentary processes indicate that about %71.43 of sediments are transported and deposited by Aeolian processes, %21.42 by fluvial processes and %7.15 by overlapping of Aeolian and fluvial processes.
Naser Baghestani Maybodi; Mohammad taghi Zare; Mohammad Abolghasemi
Volume 14, Issue 4 , February 2008, , Pages 478-489
Abstract
Wilted and dried up stands of haloxylon aphyllumspecies in afforested areas of Yazd has allways been a focal point of natural resources experts. Using various pruning treatments, the effect of pruning on the wideness of canopy cover and vigor of 12-year-old semi-trees of haloxylon aphyllumhad been evaluated ...
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Wilted and dried up stands of haloxylon aphyllumspecies in afforested areas of Yazd has allways been a focal point of natural resources experts. Using various pruning treatments, the effect of pruning on the wideness of canopy cover and vigor of 12-year-old semi-trees of haloxylon aphyllumhad been evaluated formerly. That study had been conducted in two different sections of the forest in the winter of years 1994. One section had shown a tree-density of 125 semi-trees per hectare, and the other had represented a tree-density of 250 semi-trees per hectare. The treatments included cutting at different heights of 70, 35, 10 cm and also no cutting (control). The results of that previous six-year study (1994-2000) showed that pruning increased vigority and regrowth of plants treated with different levels of pruning. The 35-cm pruning treatment was preferred over other treatments. At the end of growing season of year 2005, eleven years after pruning treatments, the same trees were evaluated for the second time. Results of the new study (in 2005) showed that while non-pruning (control) 23-year-old semi-trees are wilted and almost dried up, the semi-trees with pruning are vigorous and healthy. In terms of canopy cover and height, no significant difference was found between trees with different pruning treatment in the 5 years of 2000-2005. There was a significant reduction in the canopy cover and height of non-pruning (control) semi-trees (p<0.05). For the semi-trees which had been cut at a height of 35 cm, the diameter of canopy and the height were 262 and 164 cm, respectively. This semi-trees showed a good resistance against movement of sands and sand dunes.
Ali Akbar Safdari; Zahra Mahmoodi; Hadi Memarian Khalilabad
Volume 15, Issue 3 , January 2008, , Pages 304-319
Abstract
In the wind erosion process, there are three areas: detachment area, transport area and deposition area. The prevention of sediments movement in the detachment area is a basic task. Knowing origin of sediments of sand dunes, the recognition of the detachment regions is necessary. In order to origin study ...
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In the wind erosion process, there are three areas: detachment area, transport area and deposition area. The prevention of sediments movement in the detachment area is a basic task. Knowing origin of sediments of sand dunes, the recognition of the detachment regions is necessary. In order to origin study of eolian sediments in the Mokhtaran plateau, step-by-step method (Ekhtesasi-Ahmadi) was used. This study is done at tow stages: direction finding and location finding. To direction finding of taking sector, firstly by questionnaire completion, local winds information were gathered. Then satellite image (ETM+, 2002) and field investigations, the erg morphological map was provided. By studying of wind regime and wind rose drawing, the erosive winds were recognized. After recognition of taking sector (surrounding pediments of sand dunes), the location finding phase was started. In this stage by geomorphologic studying of taking sector and sampling into facieses, the mineralogical and morphoscopical studies of sand dunes and taking sector sediments were done. At least, the study shows that KUPH (schist and phyllit), Colored melonged and other sensitive formations in the east and southeast areas are basic sources of eolian sediments for Mokhtaran erg, which deposited by water erosion in the different parts of Mokhtaran plateau. In consequence of east and southeast erosive winds, these sediments are taken and deposited around of DAGH. These sediments were displaced so much time by winds that have different directions inside of the erg (north and northwest winds) and formed pyramid sand dunes. Thus in order to preventing of wind erosion, the initial sources i.e. KUPH formation and surrounding pediments must have in mind.
Hadi Memarian Khalilabad; Ali akbar Safdari; Mohammad reza Ekhtesasi
Volume 15, Issue 1 , January 2008, , Pages 26-41
Abstract
In wind erosion process, there are three areas: source area, transport area, and deposition area. The prevention of sediments movement in the source area is a fundamental task. In stabilizing source sediments of sand dunes, recognition of the taking regions is essential. In order to study the in order ...
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In wind erosion process, there are three areas: source area, transport area, and deposition area. The prevention of sediments movement in the source area is a fundamental task. In stabilizing source sediments of sand dunes, recognition of the taking regions is essential. In order to study the in order to study the source of eolian sediments in the Fadisheh region, a step-by-step method (Ekhtesasi-Ahmadi) was used. This study was done in two stages: direction finding and location finding. First, information about the direction of local winds was gathered by questionnaire. Then satellite image (ETM+, 2002) and field investigations, the erg morphological map was determined. By studying wind regime and wind rose drawing, the erosive winds were recognized. After recognition of source sector (southeast and east sector), the location finding phase was started. In this stage by geomorphologic studying of the source sector and sampling into facieses, the mineralogical and morphoscopical studies of sand dunes and source sector sediments were done. Finally, paying attention to other evidences as the direction of Barkhan dunes (Southeast-Northwest), high intensity of energy for East winds, the existence of heavy minerals as Hematit, Chamosite, Edenite and Sphalerite in sand dune and source area soil samples, average median of sand dunes sediment samples (~210micron), symmetrical shape of sand dunes sediments frequency graph, was found that the source of eolian sediments are in the middle distance relative to sand dunes and are as follows: damaged Haloxylon forests, non vegetative area, unutilized lands in the southeast sector of the clay plains, Microlithic pediments and non vegetative lands in the margins of Kal-e-Shoor and Kal-e-Shoor River bed.
Ebrahim khalifeh; Mojtabah Pakparvar; Mohammad reza Kaviyanpoor
Volume 14, Issue 3 , January 2007, , Pages 403-420
Abstract
Active sand dunes particularly barkhans are serious threats for adjacent civilians live, agricultural lands and economic activities. Deployment quality and motion paths of these dunes are main targets in wind erosion studies in deposit regions. These targets need the active and inactive dunes to be identified. ...
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Active sand dunes particularly barkhans are serious threats for adjacent civilians live, agricultural lands and economic activities. Deployment quality and motion paths of these dunes are main targets in wind erosion studies in deposit regions. These targets need the active and inactive dunes to be identified. Edges and borders are evident characteristics of wind deposits and sand dunes. Inactive (old) dunes are more voluminous and smooth. Furthermore active dunes have distinct feature. Also temperature, humidity and plant cover variation lead to change surface and feature of inactive dunes. These changes can’t be observed in one band images. Therefore making uses of filters particularly non directional edges enhancement and band ratio techniques are main ideas to process the images of these dunes especially about their activity and displacement. In present research filter and band ratio techniques have been used and consequently, third band in Profile Testing and Spectral Analysis method (in this case study b5 of Landsat ETM+) and ratio of first and second bands (in this case study b62/b4) have been introduced respectively as appropriate band and ratio for these techniques to identify and separate active (new) and inactive (old) sand dunes.