پديد آورندگان :
يماني، مجتبي دانشگاه تهران - دانشكده ي جغرافيا , لك، راضيه پژوهشكده ي علوم زمين، تهران , گورابي، ابوالقاسم دانشگاه تهران - دانشكده ي جغرافيا , شهبازي، رضا سازمان زمين شناسي و اكتشاف معادن كشور، تهران , شعباني عراقي، عارفه دانشگاه تهران - دانشكده ي جغرافيا
چكيده لاتين :
1- Introduction
The desert area, the world's widest ecosystem, covers more than one-third of its surface, and
much of Iran is affected by climatic conditions. Wind erosion due to the persistence and extent
of erosion in time and space, especially in arid areas with high damage potential. In fact, the
morphodynamic boundaries affected by climate change have changed from past to present,
leading to the expansion of the territory of wind erosion, and in recent years the dust hazard has
also become an environmental issue in these areas. One of the natural occurrences and
challenges for sustainable development and management in arid and semiarid areas is wind
erosion .Also, wind erosion is one of the causes of soil loss and due to its wide range of
activities it usually has less destructive performance than other erosions. This study was in
Damghan basin. Haj Ali Gholi Playa is affected by wind erosion.
2- Methodology
The data used are library data, meteorological statistics, maps, satellite imagery, field and
laboratory data. Initially based on geomorphological, geological, soil, vegetation, slope, land
use information, geomorphologic facies of the identified area and using 9 effective erosion
potential determination models. This process was studied and the erosion class of each facies
(sedimentation rate) was determined. Also, the wind as a motiving factor for wind erosion was
studied using the hourly data of synoptic stations over the period (2003-2019) of the
Meteorological Organization of the four stations in the basin and the annual windrose was
plotted to determine its direction and velocity. After partial understanding of the wind process
status to determine its rotational and local pattern system, the features of the evidence of wind
erosion landforms (orientation and dispersion distribution) such as barchan, Erg, sand arrows,
etc. used in field visits. Then, to determine the influence of particle size on wind erosion and
dust erosion performance in this hole, 38 samples from Playa marginal areas were taken from
Quaternary sediments for sedimentary experiments.
3- Results
According to the results of implementation of the Erifer model for determining wind erosion
potential in Damghan basin, seasonal lake bed facies, lakes and sand masses in high erosion
class and seasonal mud facies and alluvial plain in middle erosion class and the coniferous
facies and rough mountain slopes are in a low erosion class. This indicates that the lakeside
facies have the highest potential for wind erosion due to the sediment type and the
environment. This indicates that the lakeside facies have the highest potential for wind erosion
due to the sediment type and the environment. In the study of wind erosion potential, it is the
motiving factor of wind erosion that was intercepted and analyzed. The existence of a
convective cyclone corresponding to the lowest and hottest point of the plain in the region was
found to be counterclockwise in the cyclone, with converging motion toward the center. The
wind cyclonic swirl pattern to the ground screw and removal of sediments in the west and
southwest prevail hole. This moves eastward from the surface of the Earth, causing sand to be
deposited in the southeastern half of the hole as we observe the wells of the Damghan Basin in
the southeast of Playa, and in the eastern part of the wind deposits. We don't have. In fact, the
movement of wind particles is a function of wind strength and erosion, surface resistance to
erosion and erosion. The analysis of 38 sediment samples showed that sediments above 63
microns in the southwestern range of 66.18%, southeast of 76.33%, northwest of 93.62% and
north of 97.85%.
4- Discussion & Conclusions
The major causes of erosion on the surface, especially in arid and semi-arid wind erosion, to
prevent damage is necessary to study their properties. As the Quaternary lakes declined in
volume and volume and groundwater levels declined, large areas of the older lakes, including
Playa Damghan, were exposed to wind and wind erosion .The results show that a thermal
cyclonic system causes the distribution of wind sands along the playa border. Also based on
wind data and particle size the sediment movement in the region was then mutated and
suspended in creep and wind erosion has led to the creation of landforms, and the dust hazard
in the area is poorer than that. The results show that in the Damghan Playa area, due to studies
of wind erosion and various forms over time, more dust has been created than the landform
evidence we see today in the Playa border.
