Investigating the relationship between the morphology of Tamarix, Calligonum, and Iranian mesquite with the morphological characteristics of Nebkas(Case Study: Rigan, Kerman)

Extended Abstract IntroductionToday, erosion is a major factor in land degradation in Iran. Since a large portion of Iran is located in arid and semi-arid climates, wind erosion can be an effective means of destroying and causing damage in these areas. Nabkhas have distinct morphometric components from other erosional forms, but some of these parameters can affect the amount of wind sediment transfer. Identifying and measuring the relationship between these parameters and examining the process of changes in certain physical and chemical characteristics of sediments can have a significant impact on planning operations to reduce wind sand transfer and improve the analysis of sediment characteristics. The phenomenon of sand entering human centers in the southeast of Kerman province and Rigan city is considered a problem. This research aims to investigate the impact of the morphology of the species Tamarix, Calligonum, and Iranian mesquite on the morphometrics of the nabkhas in Rigan city and analyzing the measured parameters of the Nabkhas morphometry and their correlations using statistical methods. Material and MethodsThe city of Rigan, which covers 8600 square kilometers, is located south of Kerman. This city is one of the most important centers with the highest priority. Aerial photographs and Google Earth images were used to determine the area of Nabkhas, and a field visit was conducted to assess the development of Nebkas' territory.This area is a major source of wind erosion in Kerman province and even in the country. The severity of erosion is such that date trees with a height of more than 5 meters are buried under sand sediments. The first step was to measure the morphometric characteristics of Nabkhas along 6 one-kilometer transects. The characteristics of the Nabkhas of each of the Calligonum, Iranian mesquite, and Tamarix plants were measured separately. To investigate the characteristics of Nabkhas, the morphological characteristics of Nabkhas including height and diameter of the base were measured. The characteristics of the vegetation that forms Nabkhas were studied by measuring plant morphological factors, such as crown diameter and plant height. Statistics were collected from 44 farms that use Tamarix plants, 51 farms that use Iranian mesquite plants, and 38 farms that use Calligonum plants in total.Results The regression analysis between plant height and Nabkhas height indicates that the slope of changes in Nabkhas height compared to changes in vegetation height is higher in sedge and mesquite plants than in Calligonum. The height of Nebka is more affected by Tamarix changes than the other two plants. Based on the evaluation of the regression results between the canopy diameter and the canopy height, it can be concluded that the slope of the canopy height changes is greater than the slope of the canopy diameter changes in Calligonum and Iranian mesquite plants, respectively. It can be concluded that the Calligonum plant's crown diameter has a greater effect on Nabkhas' height changes than the other two plants. The regression results between plant height and root diameter indicate that the slope of root diameter changes is greater than that of plant height changes, respectively. It can be concluded that the height changes of the Tamarix plant are more significant in influencing the diameter changes of the Nabkhas base than the other two plants. The slope of diameter changes of the base compared to the changes of diameter of the plant crown, respectively, is higher in calligonum and mesquite plants than in Tamarix. Changes in the diameter of the crown of the Calligonum plant have a greater effect than the changes in the diameter of the other two plants on the changes in the diameter of the base of Nabkhas. Results and DiscussionNabkhas with Iranian mesquite have a longer base length in proportion to height than Nebkhas with Tamarix and Calligonum. The geomorphological characteristics of four plant species in Lut Plain's western region were examined, and it was found that the nebkhas with Tamarix have an average height of 1.5 meters and an average base of 4.2 meters. The Nabkhas' Iranian mesquite has an average height of 1.5 meters and an average base of 1.6 meters. Thus, their research results are in accord with the results of this research. According to the correlation results, the morphology of Tamarix, Calligonum, and Iranian mesquite species is significant compared to the morphometric characteristics of Nabkhas, which is consistent with the results (2 and 16). According to the regression results, Tamarix plant has a higher slope of changes in height compared to vegetation. The Calligonum plant has a higher slope of changes in height compared to diameter of plant canopy compared to the other two plants. On the other hand, the slope of changes in the diameter of the Nabkhas base compared to the changes in plant height of Tamarix is greater than that of the other two plants. The slope of the changes in the diameter of the base compared to the changes in the diameter of the plant crown is greater than that of the other two plants. The morphological characteristics of the sediments in the studied area indicate that storms are extremely strong throughout the year, causing a significant movement of sand in the area.