Spatial Distribution and Potential Ecological Risk of Heavy Metals in Sediments of Ulansuhai Lake during Ice-on Period

摘要

In order to understand the heavy metals distribution and environmental risk level of sediments in Ulansuhai Lake during ice-on period, concentrations of heavy metals (Cu、Fe、 Mn、 Zn、 Pb、 Cr、 Cd、 Hg、 As） were measured. Samples were taken at 13 positions in January 2009. To evaluate the potential risk by potential harm Hokinson, and draw potential ecological risk index distribution by ArcGIS9.2, Finally, the ecological risk classification area was calculate quantitatively according to potential ecological risk index classification standard. The results demonstrated that (l)heavy metals in surface sediment have the similar spatial distribution pattern which are high at north and south are low at middle and eastern. (2)The potential risk index of heavy metals in the sediment decreases as follows: Hg> Cd> As> Cu> Pb> Cr> Zn> Mn> Fe. Hg, Cd played as the main pollution factor during ice-on period. Potential ecological risk of Hg and Cd. (3)potential ecological risk index during ice-on period was 177.45-685.58 respectively and means value was 389.73. Potential ecological risk indexes of area in level II , IIIand IV accounted for the total area 1.88%, 96.2%, 1.92% of total area during ice-on period.