Heavy metal and ecological risk assessment of river sediment in the upper reaches of the Yangtze River——Taking Dayao County in Yunnan Province for example
The quality of rivers'environments is influenced by the spread and buildup of heavy metals in sediments.To assess the condition of aquatic ecosystems in the Yangtze River Basin,this research focuses on analyzing the heavy metal content and pollution levels in the sediment of major rivers in Dayao County.Various methods such as the modified Nemerow index,potential ecological risk index,cluster analysis,and principal component analysis are employed to evaluate the current state of heavy metal pollution and identify the sources of these pollutants.Findings reveal that the sediment in Dayao County's major rivers has a pH of 8.0,indicating a slightly alkaline nature.The potential ecological risk index for each heavy metal element and the overall comprehensive potential ecological risk index for each river basin are relatively low,suggesting a clean overall status.Among the pollution risk index values of the major rivers studied,Cd and Hg are the primary contributors,each making up around 30%of the total,highlighting these two heavy metals as the main sources of potential ecological risks in the sediment.For instance,the average Cu content in the Jiangdi River sediment is 372.35 mg/kg,which is significantly higher than the background values for soil in Yunnan and sediment in the Yangtze River system.The Nemerow pollution index in the area has reached 3.72,signifying severe pollution.It is important for the local community to focus on addressing the copper pollution resulting from mining activities.
Sediments of riverheavy metalthe modified Nemero index methodpotential ecological riskDayao County
NETL
NSTL
万方数据
