Migration of risk elements within the floodplain of the Litavka River, the Czech Republic

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F19%3A00500190" target="_blank" >RIV/61388980:_____/19:00500190 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985831:_____/19:00500190 RIV/44555601:13520/19:43894490 RIV/00216208:11310/19:10397037 RIV/61989592:15310/19:73600613

Výsledek na webu

<a href="http://hdl.handle.net/11104/0294721" target="_blank" >http://hdl.handle.net/11104/0294721</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.geomorph.2018.12.010" target="_blank" >10.1016/j.geomorph.2018.12.010</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Migration of risk elements within the floodplain of the Litavka River, the Czech Republic

Popis výsledku v původním jazyce

Floodplains are one of the most complex sedimentary environments used for the reconstruction of human impacts on fluvial deposition and catchment pollution. Studies of polluted floodplains require an interdisciplinary approach, including tools from geomorphology, geophysics, and geochemistry. The spatial distribution of pollutants can reflect not only pollution history but also post-depositional transfers of pollutants. The Litavka River (SW Czech Republic) was impacted by historical mining and processing of Ag-Pb-Zn-Sb sulfidic ores, which resulted in a severely polluted floodplain. Previous studies revealed that nearly all of the floodplain deposits of the Litavka River downstream from the ore district are polluted, indicating massive floodplain aggradation. Our aim was to decipher the role of aggradation in floodplain development by investigating the pollutant distribution in the floodplain fill. Another important goal was to distinguish polluted (modern) sediments from secondarily polluted sediments (which were previously pristine) caused by extensive lateral and vertical post-depositional chemical migration of risk elements within the floodplain fill. The floodplain topography was characterized via a digital terrain model (DTM), the internal structure of the floodplain was determined by electrical resistivity tomography (ERT). Sediment samples were collected from hand-drilled cores across the floodplain along the ERT line, and their elemental composition and magnetic susceptibility were analysed. Dating of sediments was performed via optically stimulated luminescence (OSL). The concentrations of Zn, Pb and Cd, along with values of magnetic susceptibility decreased with increasing distance from the current river channel. However, the spatial patterns of risk elements were more complicated than expected in a fluvial sedimentary environment. Inter-element relationships of risk elements exhibited a complex pattern, with abundant outliers that required the use of robust regression. The results helped distinguish the geochemical difference between proximal and distal floodplains, and to identify zones of anomalous inter-element ratios attributed to post-depositional element migration. The observed migration was significant, and not only vertical but horizontal, spanning a distance of approximately half the floodplain width. Metal migration explains why unpolluted sediments are practically missing from the floodplain fill of the Litavka River. Use of pollution chemostratigraphy, without considering the possibility of post-depositional migration of risk elements, could lead to overestimation of the volume of younger sediments deposited directly within the floodplain and to overestimation of the role of aggradation processes.

Název v anglickém jazyce

Migration of risk elements within the floodplain of the Litavka River, the Czech Republic

Popis výsledku anglicky

Floodplains are one of the most complex sedimentary environments used for the reconstruction of human impacts on fluvial deposition and catchment pollution. Studies of polluted floodplains require an interdisciplinary approach, including tools from geomorphology, geophysics, and geochemistry. The spatial distribution of pollutants can reflect not only pollution history but also post-depositional transfers of pollutants. The Litavka River (SW Czech Republic) was impacted by historical mining and processing of Ag-Pb-Zn-Sb sulfidic ores, which resulted in a severely polluted floodplain. Previous studies revealed that nearly all of the floodplain deposits of the Litavka River downstream from the ore district are polluted, indicating massive floodplain aggradation. Our aim was to decipher the role of aggradation in floodplain development by investigating the pollutant distribution in the floodplain fill. Another important goal was to distinguish polluted (modern) sediments from secondarily polluted sediments (which were previously pristine) caused by extensive lateral and vertical post-depositional chemical migration of risk elements within the floodplain fill. The floodplain topography was characterized via a digital terrain model (DTM), the internal structure of the floodplain was determined by electrical resistivity tomography (ERT). Sediment samples were collected from hand-drilled cores across the floodplain along the ERT line, and their elemental composition and magnetic susceptibility were analysed. Dating of sediments was performed via optically stimulated luminescence (OSL). The concentrations of Zn, Pb and Cd, along with values of magnetic susceptibility decreased with increasing distance from the current river channel. However, the spatial patterns of risk elements were more complicated than expected in a fluvial sedimentary environment. Inter-element relationships of risk elements exhibited a complex pattern, with abundant outliers that required the use of robust regression. The results helped distinguish the geochemical difference between proximal and distal floodplains, and to identify zones of anomalous inter-element ratios attributed to post-depositional element migration. The observed migration was significant, and not only vertical but horizontal, spanning a distance of approximately half the floodplain width. Metal migration explains why unpolluted sediments are practically missing from the floodplain fill of the Litavka River. Use of pollution chemostratigraphy, without considering the possibility of post-depositional migration of risk elements, could lead to overestimation of the volume of younger sediments deposited directly within the floodplain and to overestimation of the role of aggradation processes.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10511 - Environmental sciences (social aspects to be 5.7)

Projekt

<a href="/cs/project/GA15-00340S" target="_blank" >GA15-00340S: Antropogenní znečištění a stavba říčních niv: dva fenomény a jediný příběh</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Geomorphology

ISSN

0169-555X

e-ISSN

—

Svazek periodika

329

Číslo periodika v rámci svazku

MAR

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

46-57

Kód UT WoS článku

000460085400004

EID výsledku v databázi Scopus

2-s2.0-85059623726