| Atmospheric dustfall is the aerosol particles on the surface of the Earth, which is very significant to the biogeochemical cycles and the environment. Atmospheric dustfall flux refers to the quality of the particulate matter falling on the surface per unit area per unit time. It is the quantitative description of the basic parameters of atmospheric dust properties. Atmospheric dustfall flux can be used in the study of atmospheric dust transport and deposition mechanisms. As a character of environmental quality, atmospheric dustfall flux reflects the concentration levels of particulate matter, indicating the soil, air and other environmental conditions near the surface. Hebei Province is an important dust deposition area from Central Asian north Pacific. The mechanism of the current atmospheric dust deposition in this region is still unclear. The thesis aims to analyze the changes of atmospheric dustfall flux according to time and space in Hebei Province for nearly 20 years. Probing into atmospheric dust deposition mechanisms, the paper may help people understand the quantity of atmospheric dust transport and provide the basis to improve the air quality in Hebei.Based on 11 cities in Hebei Province from 1986 to 2006 monitoring data of atmospheric dustfall flux, this research explores temporal and spatial variation of atmospheric dustfall flux in Hebei Province by mathematical statistics and wavelet analysis. The results showed that: (1) In the last 20 years, the average dustfall flux was in the range of 16.09 37.26 t·km-2·month-1 Hebei Province. Among them, the highest value was in 1988, and the lowest value was in 2005.Its general tendency was downward. On the one hand dustfall flux decline in Hebei Province was due to a downward trend of dusty weather in northern China, on the other hand the government gradually controlled dust in transportation and construction. Over the last 20 years the area of the paved road and green area in Hebei Province increased, as a result, it reduced dust emission by sources of local, led to reduction of dust flux value. In addition to Tangshan, Hengshui, Cangzhou and Xingtai four cities, before and after 1996 there is a low peak of dust flux in other cities . Dust flux occurred in 1996 due to low peak of dust flux value. During this period it was mainly affected by large-scale of climatic background conditions. (2)The maximum dustfall flux is in spring, followed by winter, autumn and summer. In spring, the provincial average dustfall flux was 29.79 t·km-2·month-1. It is equivalent to 65.6% of the mean dustfall flux in the East Part of North China(42.35 t·km-2·month-1), 47.5% of the mean dustfall flux in the Gobi Desert of north China ( 58.56 t·km-2·month-1) and about 12.4 times of the average dustfall flux on North Pacific Ocean. The average dustfall flux was highest in April which was 31.84 t·km-2·month-1, and the lowest was 18.455t·km-2·month-1in August. (3) There are nine cities in Hebei Province dustfall flux occurred 5 to 6 years, 7 years, 9 years and 11 years cycle. Especially in the four seasons of dustfall flux, there were the cycle of 6.5 years . In Handan, Xingtai, Baoding, Qinhuangdao, Langfang, dustfall flux in the province average 6.5 years in the spring cycle. Only seasonal cycle of dustfall flux in Tangshan and Shijiazhuang was not significantly different, reflecting that there dust flux was greatly influenced by anthropogenic sources.By using statistical analysis module of ArcGIS software, the research analyzed dustfall flux variability and semi-variance function interpolation in 11 cities. The main conclusions drawn are as follows: (1) The overall spatial distribution of dustfall flux from the Northwest to the southeast was decreasing in Hebei Province. Dustfall flux in the peak was in Zhangjiakou, the lowest areas were in the center of Handan and Tangshan which was formation of high and low ends of the distribution trend. Northwest dustfall flux is due to the high value area of dust storms increasing in dust deposition. The second highest dustfall flux value area because of the two cities are dominated by heavy industry city, where the main pillar industries are steel, coal, building materials, and coal, iron ore and metallurgical raw materials in Handan, mineral building materials is widely distributed, so people have more dust emission, resulting in higher dustfall flux. (2) Dustfall flux spatial distribution of Hebei Province has obvious correlation and direction of spatial effects. The average dustfall flux in 1990 and average dust flux in January of the past 20 years have south-north directional effect, other years and month average dust flux are close to northeast - southwest directional effect. All this indicates that the dust flux are evenly distributed, and it has more similar characteristics in farther spatial distance in this direction. (3) In Hebei Province during the past 20 years, the overall spatial distribution of dustfall fluxes changed little, and high-value centers are in Zhangjiakou, low areas are in Hengshui, Cangzhou, Langfang, and Qinhuangdao.
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