Distribution Characteristics, Source Identification and Risk Assessment of HMs in the Communicate Area of Weihe River and Qianhe River, China

With the acceleration of new-type urbanization and beautiful countryside construction, the urban fringe has become one of the main spaces for urban expansion and environmental quality improvement.Water and sediment samples are collected from 8 sites at the intersection of the Weihe River and the Qianhe River in the eastern suburbs of Baoji City.The results show that from the upper reaches to the lower reaches of the river, the HMs concentration of the mainstream is Weihe River>Qianhe River, and the upper stream < the lower stream.The highest concentrations of Cr, Ni, Pb, and Hg in river water exceeded GB3838 Class II standard limits.The HM concentration in sediments from, high to low, is Zn>Cr>Cu>Ni> Pb>As>Cd>Hg.The degree of potential ecological risk from the upper reaches to the lower reaches of the river was: high → considerable → moderate → considerable.However, the ecological risk degree of individual metal elements is Hg>Cd>Pb>Cu>As>Ni>Cr>Zn.The main pollution elements are Hg, Pb, and As, mostly from point-source discharge and upstream tributaries.In the future, point-source emissions should be strictly controlled, and land use planning should be adjusted.