بررسی پتانسیل یابی فرسایش بادی و مناطق تولید گردوغبار در پلایای جازموریان

فرسایش بادی و گردوغبار از چالش های زیست محیطی است که جامعه جهانی در زیست بوم های حساس و شکننده مناطق خشک با آن روبروست. این دو پدیده در نواحی بیابانی از پتانسیل تخریب بالایی برخوردارند به همین جهت شناخت و مدیریت آنها همواره مورد توجه است. این پژوهش در حوضه جازموریان و پلایای آن انجام شده است. داده های مورد استفاده شامل: منابع کتابخانه ای، داده های هواشناسی، نقشه ها، داده های میدانی و آزمایشگاهی بودهاند. در این پژوهش برای شناخت وضعیت باد منطقه به عنوان عامل محرک این دو فرآیند، گلباد های سالانه با داده های ساعتی ایستگاه های سینوپتیک در بازه زمانی (2003-2019) برای 6 ایستگاه موجود در حوضه ترسیم و وضعیت باد منطقه رهگیری شد. سپس با استفاده از مدل(اریفر) 9 عامل موثر در تعیین پتانسیل فرسایش بادی در رخساره های ژئومورفولوژی حوضه بررسی و میزان رسوبدهی آنها مشخص گردید. برای تشخیص تاثیر اندازه ذرات در عملکرد فرآیندهای بادی نیز، 20 نمونه رسوب سطحی از نقاط شاخص منطقه برداشت و پس از دانه سنجی مورد تحلیل قرار گرفت. نتایج مدل اریفر بیانگر این است که رخساره(توده های ماسه ای ریگزار) با امتیاز 107.5 دارای بیشترین میزان رسوبدهی و در بالاترین کلاس فرسایشی است و برهمین اساس موقعیت این رخساره در نیمه شرقی و جنوب شرقی پلایای جازموریان بر روی نقشه مشخص شد. بررسی ویژگی ه ای بادهای غالب در دوره خشک سال با راستای غالب شمال غربی و غرب، و مطالعه ی اندازه ذرات نمونه های رسوبی در حوضه که بیشترین مقدار آنها در اندازه زیر(63 میکرون) قرار دارد، باعث حرکت این رسوبات ابتدا به صورت معلق سپس جهش و خزشی بوده است. مطالعات نشان دادکه مخاطره گرد و غبار عملکرد وسیعی در سطح پلایا و حواشی آن دارد و پلایای جازموریان به دلیل شرایط محیطی یکی از منشاهای گردوغبار در جنوب شرق کشور محسوب می شود.

Investigating the potential of wind erosion and dust production areas in Jazmourian Playa

Extended abstract1 IntroductionIn this century, wind erosion as one of the most important processes in arid and semiarid regions has affected about onesixth of the world's land area. Wind erosion is usually attributed to the process of soil particles being removed and displaced by the wind. Wind is one of the dominant processes in arid, semiarid, and subarid regions and is the result of wind dynamics, transport of soil or sediment particles, and the development and evolution of desert roughness based on erosion and sedimentation intensity.The risk of wind erosion and dust is also more severe in areas where the soil is loose, dry, and bare, with high winds and high repetition. This study was conducted in Jazmourian basin and its playa. Jazmurian Playa has been studied as the most important area affected by wind erosion and the source of dust hazard in the southeast of the country; because these two hazards are often found in closed basins of old lakes or playa that contain loose sediments, and they are disconnected, they are happening.2 MethodologyData used are library data, meteorological statistics, maps, field, and laboratory data. At first, using the (Eriffer) model, nine effective factors in determining the wind erosion potential in the geomorphological facies of the basin were investigated, and their sedimentation rate was determined. The annual windroses were plotted with hourly data from the synoptic stations over the period (20092019) for six stations, and the wind situation of the area was analyzed. Then, 20 surface sediment samples were taken from the area to determine the effect of particle size on the performance of wind processes, and Granulometry was performed. And the position of the sanddune as the end point of wind erosion and the areas affected by the dust were also identified.3 ResultsAccording to the results of the implementation of the Eriffer model for determining the wind erosion potential in the Jazmourian basin of high and diverse sandstone facies very high erosion class and seasonal litter lithofacies, seasonal muddy salt marsh, terraces lakes and alluvial plain. There is a lot of erosion in the classroom. Also, alluvial facies are in middle erosion grade and uneven mountain slopes in low erosion grade. In fact, in the Jazmourian basin, there are scattered sandy masses, but the highest distribution is in the southeast of Playa, with 44.49% of sedimentation of the whole basin. The wind Baft situation in the area indicates that the maximum velocity at the station is 2.10 to 3.60 m / s. The highest wind speed at this station is in the range of 5.70 to 8.80, which accounts for about 2 percent of all winds. The Bam Station Wind in different directions at speeds below 4.5 m / s. Khash Station is about 2 percent of the winds in the speed range of 8.8070.70, and about 80 percent is between 0.50 to 3.60 m / s. Jiroft Station is about 1 percent of the winds in the speed range of 8.8070. Nikshahr Station At this station, about 2% of the winds blow at a speed of 5.70 to 3.70 / 60 and the Other at lower speeds. Iranshahr Station about 80% of the winds in this station are northeast to southeast and are classified at speeds of 0.50 to 3.60 m / s. Annual windrose show at stations in the area Local winds can create local dust. The results of the analysis of the samples show that 74.75% of the eastern Playa sediments, 76.25% of the southern Playa sediments, 67.50% of the northern sediments, and 95% of the Playa center sediments are below 63 microns in size. Surface sediments are the environment for the production of dust.4 Discussion Conclusions The results show that the low and flat topography, the presence of fine particles in the sediments, and the dominant winds during the dry season, with the dominant northwest and west direction, caused the sediment to move suspended, then jump and creep. And the dust hazard has Extensive performance on the playa and its margins, and more importantly, the Jazmourian playa is one of the main sources of dust in the southeast of the country. Also, the areas covered by dust hazards are greater in the central, southern and, western margins of the hole than in other areas.