Sima Pourhashemi; mehdi boroghani; abolghasem Amirahmadi; MohamadAli Zanganeh Asadi; Mahdi Salhi
Abstract
Due to the drought and land use changes in recent years, dust storm phenomenon in Iran has increased. The purpose of this research is to identify and prioritize dust source areas using bivariate models (probability model of event weight and frequency ratio model) in R software environment and determine ...
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Due to the drought and land use changes in recent years, dust storm phenomenon in Iran has increased. The purpose of this research is to identify and prioritize dust source areas using bivariate models (probability model of event weight and frequency ratio model) in R software environment and determine the importance of each of the environmental factors affecting it in Khorasan Razavi province. To this porpuse, 65 dust extraction points were identified in the study area and a dust distribution map was prepared. Then maps of each of the factors influencing the occurrence of dust including soil maps, lithology, slope, vegetation index (NDVI), distance from the river, geomorphology and land use were prepared. Using the frequency and event weighting models, the weight of each effective factor and the relationship between each of the factors and the points of dust source were determined and, finally, priority maps of the dust source areas were prepared for the case study. Models were evaluated using the ROC curve. According to the results of both models, geomorphology units, land use and slope have the most effect on the occurrence of dust in the region, and both models have a frequency ratio and event weight with a sub-curve of 0.818 and 0.825, respectively. They accept.
Ataollah Kavian; Feryal Hayavi; Mehdi Boroghani
Abstract
Splash erosion recognized as first stage of erosion process that results of bombing soil surface with rain drop. Falling rain drops to soil surface resulted moving soil particles and destructing soil structure. At this research effects of various PAM rate (0, 2, 4 and 6 kg.ha) on splash erosion on three ...
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Splash erosion recognized as first stage of erosion process that results of bombing soil surface with rain drop. Falling rain drops to soil surface resulted moving soil particles and destructing soil structure. At this research effects of various PAM rate (0, 2, 4 and 6 kg.ha) on splash erosion on three soil textuere clay, silty clay and sandy clay loam was tested. Simulations were done with rain intensity of 95 mm/h using a FEL3 rainfall simulator in laboratory. Splash erosion rate were measured using splash cup. Results showed that there is no statistically difference between different soil textures in order to decreasing splash rates. Effect of different applying PAM in splash erosion rate showed that there is significantly differences between control treatment with 4 and 6 Kg/ha treatment in 95% level (Fvalue=4.5, Pvalue= 0.039) in sandy clay loam soil texture. Also the results showed splash erosion rates have decreased by 42.3 and 52 percent comparing to control treatment when applied 4 and 6 Kg/ha treatments. Our findings can be useful for better management of agricultural soils in order to sustainable yield and soil sonservation.