Document Type : Original Article
Subjects
Extended Abstract
1. Introduction
Dust storms are one of the most significant sources of atmospheric pollution, occurring in arid and desert regions. Iran is constantly under the influence of dust storms due to its proximity to a large part of the desert areas. Dust storms have a negative impact on climate, weather patterns, the air quality of ecosystems, and human health. One of the most essential measures to control and reduce the destructive impact of dust storms on the environment and human health is dust source detection and conducting specialized studies on them. Since the drying of the Hor al-Azim wetland and its transformation into a sabkha has created lands susceptible to erosion and dust centers, this study aims to identify places with high potential for dust storms in the Hor al-Azim wetland, as well as potential assessment of the existing sabkhas in this wetland in the production of dust storm with a combination of field, laboratory studies and the use of multi-criteria decision-making model WASPAS.
2. Materials and Methods
In this research, to identify dust storm source areas, the initial areas that have soil erosion potential are determined. The determining factors of soil erosion in this study are the physical and chemical properties of the soils of the study area, including salinity, PH, bulk density, sodium absorption ratio, and amount of clay, silt, and sand, as well as vegetation and land surface maps. After determining the effective criteria, soil property maps were prepared using the ordinary kriging method, and vegetation and land surface temperature maps were prepared using NDVI and LST indices, respectively. In the WASPAS model, in order to prioritize the options, it is necessary to weigh the criteria. For this purpose, the weight of these criteria was calculated by the Shannon entropy weighting method, and finally, the options were prioritized with the WASPAS model, and the final 5-class map of dust storm generation potential was prepared based on the output of this model.
3. Results and Discussion
The results of this study indicate that the salinity level in most of the study area is in the very high salinity class, and there also is a sodium problem. The moisture map of the region illustrates low moisture in the southern and southeastern parts. The average bulk density was low, which indicates the fine-grained nature of the soils in the study area, with the lowest value in the southern parts. Also, in the soils of the study area, the amount of silt is higher than the percentage of clay and sand particles. These factors reduce the strength and stability of the soil against wind erosion and erosion and ultimately lead to the formation of dust storm centers. The zonation map of the potential of sabkhas to generate dust storms using the WASPAS model reveals that 18.84% of the study area falls into the very high-risk range, 30.50% into the medium-risk range, and 14.85% into the low-risk range. The southern parts of the region are in the very high and high-risk classes, the middle parts of the region are in the medium-risk class, and the northern parts and parts of the west of the region are in the low and very low-risk classes.
4. Conclusions
The zonation map of the potential of sabkhas to generate dust storms using the WASPAS model illustrated that the southern parts of the region are in the very high and high-risk classes. Comparing this map with the maps of moisture, bulk density, and vegetation, which have a negative impact, meaning that their low levels increase the risk of dust storm formation. This comparison shows that these parts have the lowest amount of moisture, bulk density, and also the low amount of vegetation cover. Also, this map shows that the middle sections of the region are in the medium-risk class, and the northern parts and parts of the west of the region are in the low and very low-risk classes. A comparison of the findings from this study revealed that the results align with the maps of dust origin and sources in Khuzestan province, which include the dried parts of the Hor al-Azim wetland and its surrounding areas. Additionally, based on the obtained results, it can be said that the study area is one of the most significant sources of dust production in the country and, hence, requires management interventions to control or reduce its production.
5. Acknowledgment & Funding
The authors are grateful to US Geological Survey for providing the required data. The manuscript did not receive a grant from any organization.
6. Conflict of Interest
Ethical principles have been fully followed in manuscript preparation. The authors declare no conflict of interest.
