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Lanzhou University (2020)

Spatiotemporal Evolution Characteristics and Source Contributions of Dust Storm in Northern China

徐传奇;

Titre : Spatiotemporal Evolution Characteristics and Source Contributions of Dust Storm in Northern China

Auteur : 徐传奇;

Grade : Doctoral Dissertation 2020

Université : Lanzhou University

Résumé partiel
Dust storms are one of the major meteorological disasters affecting the world.It has a profound impact on climate change,atmospheric environment,human health and urban construction.Northern China,as an important part of dust sources in East Asia,has always been attacked by dust storms.The Hexi region is located in the key throat area of the ―Belt and Road‖,which is not only an important dust source in northern China but also an area heavily affected by dust storms.Therefore,it is of great significance to clarify the characteristics,transport process and potential dust sources of dust storms in the Hexi region in order to reveal the mechanism of dust sources in East Asia.This study systematically studied the spatiotemporal changes of dust storms in the Hexi region by using measured data from national air quality monitoring stations,paleoclimate proxy indicators,remote sensing satellite data,spaceborne lidar and dust emission experience models,and discussed both in terms of meteorological factors.Coupling relationship.On this basis,the dust trajectories in the study area in the past four years were screened out and their main potential dust source contributions were quantified.The main findings are as follows:A statistical survey of the frequency of dust storms recorded in North China from 1960 to 2007 found that the dust storms in the Taklimakan Desert in the west and the Hunshandake Sandy Land in the east mainly occurred in the early(77.1%)and late(72.1%).In contrast,the frequency of dust storms in the Hexi region(middle)differed slightly at the end of the 30 s,only slightly higher in the middle(45.8%).The annual changes and high incidences of dust storms in the three regions indicate that 1985 and 2000 were the years when the frequency of dust storms changed abruptly.Meteorological factors are the main factors influencing the frequency of dust storms.Corresponding to the high incidence of the three dust storm centers in northern China,the low critical wind velocity,strong solar radiation,and large evaporation can provide a reasonable explanation for the temporal and spatial differences on the scale of the dust storm.However,temperature,relative humidity,and precipitation are weakly explained.Multivariate factors reveal that the maximum wind speed is the determinant of the ten-day difference,followed by relative humidity,evaporation and solar radiation.Temperature and precipitation are not the main influencing factors.

Mots clés : Hexi region; ten-day difference; reconstruction of dust storms; dust trajectory; potential dust sources;

Présentation (CNKI)

Page publiée le 3 juin 2021, mise à jour le 26 octobre 2021