Joint Modeling of Severe Dust Storm Events in Arid and Hyper Arid Regions Based on Copula Theory: A Case Study in the Yazd Province, Iran

Tayyebeh Mesbahzadeh,Nir Y Krakauer,Mohsen Mohseni Saravi,Farshad Soleimani Sardoo,Maryam Mirakbari

doi:10.3390/cli8050064

Tayyebeh Mesbahzadeh, Nir Y Krakauer + Show 3 more

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https://doi.org/10.3390/cli8050064

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Abstract

Natural disasters such as dust storms are random phenomena created by complicated mechanisms involving many parameters. In this study, we used copula theory for bivariate modeling of dust storms. Copula theory is a suitable method for multivariate modeling of natural disasters. We identified 40 severe dust storms, as defined by the World Meteorological Organization, during 1982–2017 in Yazd province, central Iran. We used parameters at two spatial vertical levels (near-surface and upper atmosphere) that included surface maximum wind speed, and geopotential height and vertical velocity at 500, 850, and 1000 hPa. We compared two bivariate models based on the pairs of maximum wind speed–geopotential height and maximum wind speed–vertical velocity. We determined the bivariate return period using Student t and Gaussian copulas, which were considered as the most suitable functions for these variables. The results obtained for maximum wind speed–geopotential height indicated that the maximum return period was consistent with the observed frequency of severe dust storms. The bivariate modeling of dust storms based on maximum wind speed and geopotential height better described the conditions of severe dust storms than modeling based on maximum wind speed and vertical velocity. The finding of this study can be useful to improve risk management and mitigate the impacts of severe dust storms.

Highlights

Evidence suggests that the rate of natural disasters has increased worldwide from 1993 to 2002.Of 2654 natural disasters that occurred during this time period, floods and dust storms were the most common types, accounting for 70% of the total, with drought, landslides, fires, etc., making up the remainder [1].Dust storms, the result of particle transfer through the air, are an environmental problem and serious natural disaster in arid and semiarid regions
The correlation between the pairs of maximum wind speed–geopotential height and maximum wind speed–vertical velocity at the three levels of 500, 850, and 1000 hPa was determined by the Kendall coefficient on the day of the dust storm and one day before the dust storm
There is no significant correlation between variables on the day before the dust storm

Summary

Introduction

Evidence suggests that the rate of natural disasters has increased worldwide from 1993 to 2002.Of 2654 natural disasters that occurred during this time period, floods and dust storms were the most common types, accounting for 70% of the total, with drought, landslides, fires, etc., making up the remainder [1].Dust storms, the result of particle transfer through the air, are an environmental problem and serious natural disaster in arid and semiarid regions. Evidence suggests that the rate of natural disasters has increased worldwide from 1993 to 2002. Of 2654 natural disasters that occurred during this time period, floods and dust storms were the most common types, accounting for 70% of the total, with drought, landslides, fires, etc., making up the remainder [1]. The result of particle transfer through the air, are an environmental problem and serious natural disaster in arid and semiarid regions. Dust storms are caused by wind turbulence, severe winds, and rapid ascents of dust to the upper atmosphere, which requires an increase in vertical and horizontal velocity over the area. The climate and environmental conditions of arid and semiarid regions contribute to dust emissions. Dust is an important indicator for assessing the degree of desertification

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Conclusion