Numerical modeling of fine-grained sediment remobilization in heavily polluted streams. Case study: Elbe and
Abstrakt
The northern part of the Czech Republic is regarded to be heavily polluted by antecedent or ongoing heavy industrial production mainly concentrated in the riparian zones of the River Elbe and its tributaries. The toxic pollutants as heavy metals or specific organic matters tend to persist in the environment for a very long time electro-chemically bound with the cohesive fine-grained sediments burdened in the river bed and floodplains.
The predisposition of those deposits to remobilization during flooding was analyzed by numerical modeling at four stream stretches of the Elbe and its left tributary Bílina (total 113 km) by using the MIKE by DHI modeling software with different levels of horizontal plan schematization adequate to the flow conditions and available data sources. The causal discharges were relativized by the return period assessment that led to the most crucial sites detection for the future environmental risk mitigation.