干旱区生态环境知识资源中心

Year-long field observations have shown that there are spatial and temporal variations in the quantity of dust emissions for particulate matter 10 (PM10), particulate matter 63 (PM63) and vertical dust flux over different gravel surfaces (with loose sand, without loose sand, with a crust, and without a crust), with the greatest emissions occurring in the spring. The largest quantity of PM10 and PM63 emissions occurred over gravel with a loose sand surface ( and , respectively). The gravel surface without loose sand and without a crust presents the lowest values of PM63 () and PM10 (). However, the vertical dust flux was largest at over sandy surface (). Multivariate correlation analysis indicates that the quantity of PM10 is strongly negatively correlated to gravel coverage (). The quantity of PM10 dust emissions over a gravel surface with loose sand is approximately three times greater than that of a gravel surface with a crust. The mean quantity of PM10, PM63 and vertical dust flux over a gravel surface decreased with increasing gravel coverage. By comparing the quantity of PM10 dust emissions over gravel and sandy deserts, we found that gravel deserts and sandy deserts are both major sources of dust for dust storms in this region.