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Background and Objective: Considering the fact that Iran is located in semiarid climate and the harmful effects of dust storms on different ecosystems, this study aimed to identify and locate dust storms using fungal bio-aerosols (spores) and HYSPLIT model in southwestern region of Iran. Materials and Methods: MODIS satellite images and HYSPLIT model were used to investigate the temporal changes of dust masses entering the Khuzestan province. Sampling was carried out from dust storms in Abadan and Khorramshahr cities and from the soil of the dried parts of Hur al-Azim and Shadegan wetlands in a two-month period (from May to July 2019). Results: The results of numerical modeling show that Abadan and Khorramshahr cities were affected by dust storms of internal origin (from Hur-al-Azim wetland). After isolation of bioaerosols from air and soil samples, a total of 6 fungal genera were identified in soil samples and 6 genera in dust samples of internal origin by PCR-Sequencing method. Talaromyces, Alternaria, Penicillium and Aspergillus were identified as the predominant genera fungi in soil and air samples. Conclusion: With 70% similarity of fungi found in soil and air samples, it can be concluded that the main source of fungi in Abadan and Khorramshahr is Hur al-Azim wetland. [ABSTRACT FROM AUTHOR]

Soil water content is the most effective factor associated with the hydrophobic and hydrophilic changes in a soil. Water repellency in soils, is not a permanent feature; it can be reached in the dry season and reduced or eliminated in the wet season It can be said that in terms of moisture, there is a critical region that is defined as the threshold moisture content, where in lower moisture, the soil is repellent and in higher moisture, the soil is wet able. The purpose of this study was to investigate soil moisture variations on degree of hydrophobicity and determine the amount of threshold water content in soil samples of wetland around Shahr-e-Kord. In this study, some samples of Shahr- e-Kord wetland were investigated. After determining the initial moisture content of the soil, the soil hydrophobicity conditions were determined by determining the time of water droplet penetration (WDPT). Soil moisture variations were carried out using soil wetting and drying method, and in each step the soil hydrophobicity conditions were tested. Reducing water content in soil samples, led to a change in the degree of hydrophobicity in hydrophobic samples, in one soil hydrophilic soil sample, Reducing water content changed hydrophilic soil to hydrophobic soil. The threshold water content was also observed up to a maximum of 54% volumetric water content at a given point. Based on this, the higher moisture content of the threshold at this point indicates the higher soil potential for runoff generation. Soil analysis showed that soil organic matter had a positive correlation with threshold water content. [ABSTRACT FROM AUTHOR]

Quantifying land use/land cover changes is essential to monitor and assess the ecological consequences of human disturbances. Ecological condition and water quality of wetlands are highly related to the landscape characteristics, including land use/land cover (LULC) types and their fractions in the upland and the surrounding landscape. The changing characteristics of LULC in Shadegan International Wetland, Khouzestan Province, Iran, were detected in this study by using the Landsat Satellite images of the years 2001, 2014, and 2017, which were classified using the Artificial Neural Network algorithm. Then by using Land Change Modeler (LCM) in the TerrSet IDRISI software, the future of LULC changes was simulated using six independent variables and the Markov chain method. The results of this study showed that from 2001 to 2017, about 48200 ha of the wetland water was increased and around 50000 ha of saline soils and vegetation area was decreased. However, since this water increase in the wetland was due to the entry of drainage and wastewater, particularly from sugarcane cultivation around the wetland, this increase could significantly alter the hydrology, the water quality of wetland and also, the plant species composition, as compared to historical conditions; mapping these changes requires further investigations and fine scale monitoring studies. [ABSTRACT FROM AUTHOR]