Peyman Heidarian; A. Azhdari; M. Jodaki; J. Darvishi Khatooni; R. Shahbazi
Abstract
Significant damages have been caused by dust storm in Iran, particularly in Khuzestan province. Thus, as a primary step to fight with dust storms, it is necessary to map dust sources. The purpose of this study is to identify dust sources using a combination approach of remote sensing, GIS and sedimentology ...
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Significant damages have been caused by dust storm in Iran, particularly in Khuzestan province. Thus, as a primary step to fight with dust storms, it is necessary to map dust sources. The purpose of this study is to identify dust sources using a combination approach of remote sensing, GIS and sedimentology in Khuzestan province. For this, spatial data of soil, land use, climate, slope (collected from related organizations) and sedimentology were used as constraint layers, and vegetation, land surface temperature (LST) and soil moisture constitute the main layers. Sedimentology map was prepared by field sampling (900 samples) and remote sensing techniques. Also the main layers were extracted by performing the necessary computational processes on Landsat 8 satellite images. The constraint layers were applied to remove the areas without any potential of dust source. In next step, main layers weighting was done using pairwise comparison and Fuzzy Analytic Hierarchy Process (FAHP) methods. For preparing map of dust sources, each major layer was multiplied by corresponding weight and were then integrated to present a dust source zonation map. To validate the results, a field work was carried out in 180 points of source areas that verifies high accuracy of the prepared map. Results showed that 9 percent of Khuzestan plain, equivalent to 349254 hectares, are dust-generating sources. Based on land use type and area, the identified zones include destroyed range, rainfed agriculture lands, bare lands, wetlands, dried ponds and irrigated agriculture lands, respectively.
j Darvishi Khatouni; R Lak; A Mohammadi
Abstract
The Lake Urmia is the greatest hyper saline Lake in the world. This lake, located in Azerbaijan area, Northwest of Iran is an intra-continental sedimentary basin. Its area is about 6000 km2 with an average water depth of 6 meters. Hydrochemistry of the water resources of the basin showed mainly chloridic ...
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The Lake Urmia is the greatest hyper saline Lake in the world. This lake, located in Azerbaijan area, Northwest of Iran is an intra-continental sedimentary basin. Its area is about 6000 km2 with an average water depth of 6 meters. Hydrochemistry of the water resources of the basin showed mainly chloridic and sulfidic composition due to the geology of the surrounding areas and its variable lithology and Inlet water are supplied from the permanent and seasonal rivers. The hydrochemical investigations were carried out over a time period from 2007 to 2012 using previously published data together with newly collected water samples. 120 samples were collected during 6 years. The analaysis results showed Na-Mg-Cl type of the brinefrom 2007 to 2010, which is comparable with the Great Salt Lake in the USA. The chemical composition of lake in 2007 showed the percentage of sodium is higher than Magnesium. In 2011 and 2012 water composition is HCO3<<Ca+Mg. That is, the path of brine composition on the Eugster and Hardie flow diagram has changed from row III2b (Na-Mg-Cl) to (Mg-Na-Cl) in 2011 and 2012 after halite crystallization and may finally result in Mg-Cl-SO4 brine type in the future. The Sodium to Magnesium ratio is 5.12 in 2007. However, this amount in 2011 is 0.68 and 0.56 in 2012. In future, with Increasing ofevaporation, the Magnesium to sodium ratio increases and chemical compositions of the brine in the north and south of the Shahid Kalantari Highway experience more difference.
