Authors: Charles Martin*, Kansas State University
Topics: Geomorphology, Environmental Science, Physical Geography
Keywords: Trace metals, sediment contamination, monitoring of trace metals, German rivers
Session Type: Virtual Paper
Start / End Time: 3:05 PM / 4:20 PM
Room: Virtual 25
Presentation File: No File Uploaded
Previous research has documented trace metal storage (Cu, Pb, Zn) at near-channel locations along the Lahn River in central Germany. In order to monitor recent changes in trace metal concentrations at geomorphically sensitive floodplain locations, I revisited near-channel sites along the Lahn River in 2019 that were sampled for trace metals in 2007. Thirty-three cores were extracted from sites < 5 m from the active channel along a 75-km reach of the river. The median concentrations of Cu and Zn in 2019 were statistically unchanged from concentrations in 2007, but median concentrations of Pb in 2019 were statistically higher than in 2007. On an individual sample site basis, the Cu concentration decreased at 48% of the sites and the Zn concentration decreased at 57% of the sites between 2007 and 2019; Pb concentration decreased at only 30% of the sites. With one exception, concentrations of all three trace metals increased at other sites between 2007 and 2019. The reach of the Lahn River between 50 and 75 km continues to have the highest concentrations of all three trace metals. Concentrations of metals in this reach were greater in 2019 than in 2007. This reach of the Lahn River is downriver from the confluence with the Dill River, a watershed that is more contaminated with trace metals than is the upper Lahn River. It appears that relatively high concentrations of trace metals are conveyed through the Dill River into the lower Lahn River, where they are then stored in near-channel locations.