Quantifying the contributions of natural and anthropogenic dust sources in Shanxi Province, northern China

Dust storms have direct or indirect impacts on climate change and human health. Identifying and quantifying natural/anthropogenic dust sources can facilitate effective prevention and control of dust events. Based on surface real-time PM10 monitoring data, satellite remote sensing and the HYSPLIT model, this study determined the specific timing, coverage and sources of dust events in Shanxi Province, Northern China. Thus, a composite fingerprinting technique was established to quantify potential dust sources and dust contributions of single dust events. The dust oxidation model was validated, indicating that the composite fingerprinting technique was well suited to the study region. The results show that natural dust sources (67%) contributed more to the study region than anthropogenic dust sources. They were mainly from the northwest and north of the study region. Particularly, the contributions of Taiyuan (TY) and Linfen (LF) accounted for the largest (82%) and smallest (55%) proportions, respectively, both exceeding 50%. Anthropogenic dust sources contributed 33%, mainly from the east and south of the study region. The contribution of anthropogenic dust sources increased in the study region from north to south. In terms of potential dust sources, the Tengger Desert and Badain Jaran Desert (TDBD) contributed the most (26%), followed by the Otindag Sandy Land (OL) (22%). The Taklimakan Desert (TD) contributed the least (2%). The Middle Farmland region of the Hexi Corridor (HMF) in the west (15%) had the largest proportion of anthropogenic dust sources. Differences in the regional contribution of potential dust sources mainly resulted from winter winds, surface drought severity and particle size. At an insignificant distance from the study region, the contribution of potential dust sources was larger in the west than in the east and increased from south to north overall. These methods and findings can contribute to improving the ecological environment in Northern China.

Using composite fingerprints to quantify the potential dust source contributions in northwest China

Dust storms have a profound impact on the atmospheric environment, global climate change, and human health, so it is of great importance to strengthen related research. The main areas of occurrence and frequency of dust storms in northwestern China were distinguished by measuring the concentration of geochemical elements in the topsoil and atmospheric dust samples, combined with the HYSPLIT backward trajectory model, MODIS true-color satellite images, and PM₁₀ real-time monitoring data. On this basis, the composite fingerprints method was used to establish an end-member model between the concentration of dust storm samples and topsoil samples, and then to trace the sand and dust sources in northwest China and quantify their source contributions. The results showed that the main potential source areas causing sandstorms were located in the Kumtag Desert, Hexi area, and the Gobi Desert in the central and western parts of Inner Mongolia. Overall, the contributions from natural sources were greater than those from anthropogenic sources, especially at Alxa League. In addition to natural sources, anthropogenic dust sources contributed highly to dust storms, with a contribution rate of approximately 40% in cities. The main dust source in Zhangye City was from agriculture areas. The contribution of the potential dust sources in the west of the study area showed a decreasing trend from west to east because of the distance effect. Because of the influence of the prevailing westerly winds in the east, the sources of dust were relatively extensive. The Badain Jaran Desert and Tengger Desert were not the main dust sources in the study area because of artificial sand control measures and the low amounts of fine-grained components in sandy deserts. These methods and results are of great importance for sustainable development in northwest China.