آنالیز شیمیایی رسوبات بادی شرق سیستان با استفاده از تحلیل فرایندهای رسوبگذاری

Purpose: The purpose of this research is to assess the risks of wind-blown sediments in the Sistan plain and its impact on Chahnimeh vital reservoirs in the two crisis centers in the northwest of Chahnime Chahar and the northeast of Zahak with an area of about 13166 hectares in the southeast of Zabol located in the north of Sistan and Baluchistan province and in the south It is in the east of Iran. This area includes a sector in the direction of southeast to northwest, which geomorphologically has 2 units, Dashtsar and Playa. Therefore, one of the important goals of this research is to provide appropriate solutions to minimize the damage caused by wind deposits and its secondary damages, as well as to investigate and identify the risks caused by wind deposits, in the sectors of facilities, agriculture, roads, and damages to the region, especially to Chahnimeh water reservoirs. Is. In the southeast, there are forms of wind erosion in the form of barkhans, transverse barkhans, Saif and Silk. To determine the origin of these hills, the method of finding the origin of sand dunes was used and based on that, orientation and location were used in two stages. According to the review of maps and field observations, it was found that the origin of sands is the dry bed of rivers in the region. Research methodology: the method of conducting research in this research, library and field studies, review of aerial photos, review of satellite images with different time periods, review of general morphology and winds of the region (120 days) and location in terms of the study of geomorphology of the region, sampling of sediments (sedimentology and drawing relevant diagrams) and laboratory studies (XRD "X-ray diffraction" and XRF "X-ray fluorescence" tests, granulometric tests, morphoscopy and determination of statistical parameters). After performing the relevant tests, a comparative analysis and data analysis method will be done. In this research, topographic maps, geological maps, computer software such as ENVI and GIS were used.
Findings: The results of the research showed that the direction of the prevailing wind and the direction of sand transport is generally northwest to southeast, which has had the greatest effect in the region with the centrality of the existing sand dunes and 120-day winds.
Conclusion: The dangers caused by the movement of sand dunes in villages include threats to the health of residents, burial of villages, destruction of soil and public infrastructure, etc. Several factors such as strong and permanent winds, the plain's low slope and low complexity, fine-grained soil, consecutive droughts and poor vegetation play a role in the amount of sand movement on the surface of the Sistan plain and entering the Chah Nimeh reservoirs.
On a global scale, the occurrence of storms and floods are among the most destructive natural hazards (Vesterb and et all, 2022), as most accidents are caused by these two hazards (Yakshin and et all, 2022). Hazards mean natural events that potentially cause danger to humans and what is valuable to them. Hazard has the potential to cause damage, for human health, human, economic, educational activity, damage to property, damage to the environment, loss of flora and fauna, pollution and insecurity of natural disasters are dangerous (Rahimi Harabadi, 2019). The active and dynamic nature of the sand dunes causes the movement of sands towards the settlements to be more frequent and creates many dangers such as threats to the health of residents, burial of villages, destruction of soil and public facilities, and causes financial losses, migration of residents, and finally, a human disaster. (Jadidoleslami, 2019). Therefore, in order to plan fundamentally to solve the problem, it is necessary to analyze the origin of the sands, the role of the morphometric parameters of the sand dunes in the extent of their displacement, and considering the fact that the area is residential, the risks of the sands are identified and solutions are provided to reduce the risks. Sand dunes in the realm of the wind process are considered to be one of the most dynamic geomorphic phenomena on the earth's surface, which are affected by the characteristics of wind speed, direction and frequency on the one hand, and on the other hand by the characteristics of the earth's surface and sedimentary materials (Abbasnejad and Zahab Nouri, 2013). The results of studies on a scale of 1:250,000 show that the sand dunes of Iran include 11 sand seas and 39 hill fields that cover approximately 1.1 million hectares (Abbasi et al., 2019). Sandstorms are one of the most important weather phenomena that spread in many deserts and dry areas of the world, and in recent years, they have received a lot of attention, and every year these incidents cause a lot of damage and casualties in all parts of the world.In order to carry out this research, first, with direct field observations and field operations, to determine the harvesting areas, sampling was done from the transport areas and possible harvesting areas, and based on the mineralogical characteristics and the examination of the genetic relationship of the samples, the primary origin of the sediments was investigated. In order to identify the harvesting areas, sampling was done from the place of accumulation of sands, from different points of possible harvesting areas, and the genetic relationship (similar properties) of the three areas (harvesting, transportation and sedimentation) was investigated through the physical and chemical analysis of the sediments. Took Also, four synoptic stations (Zabol-Zahak-Hirmand-Hamon) were also studied.According to the presented results, the level of heavy metals in the air of Enqelab Street is not hazardous to the health of the residents. Therefore, there is no need to spend enormous expenses in this area. Nevertheless, the health of permanent and temporary residents is threatened by chromium and arsenic due to their high rate of carcinogenesis. The outcome of these investigations indicates that despite recording few different values in some places, the air pollution levels are equal in whole the area, from Enqelab Square to Imam Hossein Square. However, the air pollution level of ValiasCr rossroads is relatively considerable. This difference only has resulted from high volume of traffic in the crossroads. Unfortunately, traffic of students in this area is so heavy that solving Valiasr Crossroad’s traffic issues are considered as an important priority.