Variability and Trends in Dust Storm Frequency on Decadal Timescales: Climatic Drivers and Human Impacts

Abstract

Dust storms present numerous hazards to human society and are particularly significant to people living in the Dust Belt which stretches from the Sahara across the Middle East to northeast Asia. This paper presents a review of dust storm variability and trends in frequency on decadal timescales from three Dust Belt settlements with long-term (>50 years) meteorological records: Nouakchott, Mauritania; Zabol, Iran, and Minqin, China. The inhabitants of each of these settlements have experienced a decline in dust storms in recent decades, since the late 1980s at Nouakchott, since 2004 at Zabol, and since the late 1970s at Minqin. The roles of climatic variables and human activities are assessed in each case, as drivers of periods of high dust storm frequency and subsequent declines in dust emissions. Both climatic and human variables have been important but overall the balance of research conclusions indicates natural processes (precipitation totals, wind strength) have had greater impact than human action, in the latter case both in the form of mismanagement (abandoned farmland, water management schemes) and attempts to reduce wind erosion (afforestation projects). Understanding the drivers of change in dust storm dynamics at the local scale is increasingly important for efforts to mitigate dust storm hazards as climate change projections suggest that the global dryland area is likely to expand in the twenty-first century, along with an associated increase in the risk of drought and dust emissions.

Examining the association between dust and sediment and evaluating the impact of climate change on dust and providing adaptation

“…The area of Karkheh basin covers 4262000 hectares and covers parts of Khuzestan, Ilam, Hamedan, Lorestan, Markazi, Kurdistan and Kermanshah provinces. The most important tributaries of Karkheh River are: Gamasiab, Qarasu, Seymareh and Kashkan, which are divided into four sub-basins by the name of these four rivers [14] .…”

Interannual variations of dust activity in western Iran and their possible mechanisms

“…Dust activity has a significant impact on the environment and human health (e.g., Lin, Levy, Lei, & Bell, 2012), particularly in the "Dust Belt" that stretches from the Sahara across the Middle East to northeastern Asia (Middleton, 2019). Over the Middle East, dust emissions and concentrations have increased by 15% in the last decade (Yu, Kalashnikova, Garay, Lee, & Notaro, 2018), and it has been found that the formation of dust storms in the Middle East is influenced by both thermal and dynamic processes in the atmosphere.…”

“…Observations have shown a high frequency of dust storms in the western and southeastern parts of Iran (e.g., Cao, Liu, Wang, Yang, & Luo, 2015;Middleton, 2019;Modarres & Sadeghi, 2018), and the areas of western Iran, the Khuzestan Plain and the coastal plain of the Persian Gulf in southwestern Iran (the study areas in this research) constitute a regional belt of high-frequency dust outbreaks (Alizadeh-Choobari, Ghafarian, & Owlad, 2016). The high frequency of dust storms in these regions has been attributed to several factors, including low vegetation cover in the arid lands in Iran (Broomandi, Dabir, Bonakdarpour, & Rashidi, 2017a;Esmaili, Tajrishy, & Arasteh, 2006;Najafi et al, 2014), recent droughts in western Iran (Zoljoodi, Didevarasl, & Saadatabadi, 2013), and dust transportation from other regions (e.g., Alizadeh-Choobari et al, 2016;Yu, Notaro, Kalashnikova, & Garay, 2016).…”

The role of soils in the regulation of air quality

“…Trends in dust storms are variable across the globe, but simulations suggest global annual dust emissions have increased by 25-50% over the last century due to a combination of land use and climate changes [12,15]. Recent trends have shown that dust storm frequency has decreased in some areas (Iran, China, Mauritania), which was attributed to increases in precipitation [16].…”