关键词: 武夷山自然保护区, 植被覆盖度(FVC), Landsat影像, 遥感生态指数(RSEI), 地表灰尘, 重金属, 污染, 生态风险, 库尔勒市

Abstract: A total of 54 surface dust samples were collected from Korla. The contents of six heavy metals (Hg, Cd, As, Pb, Cr and Cu) in those samples were determined. The pollution levels and potential ecological risk of heavy metals in surface dust were evaluated using Nemerow pollution index (NPI), ecological risk index (HRI), and ecological risk warning index (IER). Results showed that the average contents of Hg, Cd, Pb, Cr and Cu in the surface dust in Korla exceeded the corresponding background values of Xinjiang soils by 3.71, 1.87, 1.96, 1.14 and 1.29 times, respectively. Among them, the surface dusts were highly polluted by Hg, lowly polluted by Cd, Pb, Cr, Cu, and slightly polluted by As. The average NPI value fell into the high pollution level. Results of ecological risk assessment indicate that Hg in surface dust fell into high ecological risk level, while Cd fell into moderate ecological risk level, and As, Pb, Cr, and Cu fell into low ecological risk level. The average value of HRI was 232.23, being at the moderate risk level. According to the classification of ecological risk warning degree, Hg in surface dust fell into low ecological warning status, while Cd, Pb, Cu, and Cr fell into early ecological warning status, As fell into no ecological warning status. The average value of IER was 4.91, being at a moderate ecological warning status. Spatial distribution of heavy metals showed that areas with high pollution and ecological risk levels were mainly distributed in the northern part in the study area. Overall, the pollution risk of heavy metals in surface dust in Korla was relatively low.

Key words: Landsat imagery, fractional vegetation cover (FVC), Wuyi Mountain Nature Reserve, remote sensing based ecological index (RSEI), surface dust, heavy metal, pollution, ecological risk, Korla.