What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)?
Hydrological variations hold a significant influence over the water chemistry in the karst systems within the critical zone. In this context, the Baget Catchment (BC) was monitored at high-resolution over 2 hydrological years. The high-frequency survey at the outlet of BC displayed multiple hydroche...
Main Authors: | , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2020-11-01
|
Series: | Environmental Sciences Proceedings |
Subjects: | |
Online Access: | https://www.mdpi.com/2673-4931/7/1/9 |
_version_ | 1797611884708364288 |
---|---|
author | Francesco Ulloa-Cedamanos Anne Probst Vanessa Dos-Santos Jean-Luc Probst |
author_facet | Francesco Ulloa-Cedamanos Anne Probst Vanessa Dos-Santos Jean-Luc Probst |
author_sort | Francesco Ulloa-Cedamanos |
collection | DOAJ |
description | Hydrological variations hold a significant influence over the water chemistry in the karst systems within the critical zone. In this context, the Baget Catchment (BC) was monitored at high-resolution over 2 hydrological years. The high-frequency survey at the outlet of BC displayed multiple hydrochemical patterns in response to hydrological variations, mixing water sources, and biogeochemical processes. Among the major elements, sulfate exhibited the widest relative variation during flooding and showed a significant dilution, whereas calcium and bicarbonate revealed a chemostatic behavior as a result of carbonate dissolution in the karst. Hysteretic analysis evidenced the control of different hydrological reservoirs over the stream transport processes of dissolved elements. The concentration of dissolved organic carbon increased during the hydrograph rising limb and was controlled by surface runoff. The relationships between Ca<sup>2+</sup> and HCO<sub>3</sub><sup>−</sup> concentrations and stream discharge exhibited hysteresis patterns with counterclockwise loops, unlike all other elements, due to the carbonate weathering by biogenic CO<sub>2</sub>-rich water. Finally, high-frequency sampling during storm events improved the understanding of the factors controlling the hydrochemical dynamic of the Baget stream water. The relative contributions of the karst and epikarst zones, of rainwater, as well as the role of different biogeochemical processes and the hydrological conditions were highlighted. |
first_indexed | 2024-03-11T06:35:00Z |
format | Article |
id | doaj.art-7364a0298ff6406bb184b06a6c5ba100 |
institution | Directory Open Access Journal |
issn | 2673-4931 |
language | English |
last_indexed | 2024-03-11T06:35:00Z |
publishDate | 2020-11-01 |
publisher | MDPI AG |
record_format | Article |
series | Environmental Sciences Proceedings |
spelling | doaj.art-7364a0298ff6406bb184b06a6c5ba1002023-11-17T10:58:41ZengMDPI AGEnvironmental Sciences Proceedings2673-49312020-11-0171910.3390/ECWS-5-08058What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)?Francesco Ulloa-Cedamanos0Anne Probst1Vanessa Dos-Santos2Jean-Luc Probst3Laboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Auzeville Tolosane, 31326 Castanet Tolosan, FranceLaboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Auzeville Tolosane, 31326 Castanet Tolosan, FranceLaboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Auzeville Tolosane, 31326 Castanet Tolosan, FranceLaboratoire Écologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Auzeville Tolosane, 31326 Castanet Tolosan, FranceHydrological variations hold a significant influence over the water chemistry in the karst systems within the critical zone. In this context, the Baget Catchment (BC) was monitored at high-resolution over 2 hydrological years. The high-frequency survey at the outlet of BC displayed multiple hydrochemical patterns in response to hydrological variations, mixing water sources, and biogeochemical processes. Among the major elements, sulfate exhibited the widest relative variation during flooding and showed a significant dilution, whereas calcium and bicarbonate revealed a chemostatic behavior as a result of carbonate dissolution in the karst. Hysteretic analysis evidenced the control of different hydrological reservoirs over the stream transport processes of dissolved elements. The concentration of dissolved organic carbon increased during the hydrograph rising limb and was controlled by surface runoff. The relationships between Ca<sup>2+</sup> and HCO<sub>3</sub><sup>−</sup> concentrations and stream discharge exhibited hysteresis patterns with counterclockwise loops, unlike all other elements, due to the carbonate weathering by biogenic CO<sub>2</sub>-rich water. Finally, high-frequency sampling during storm events improved the understanding of the factors controlling the hydrochemical dynamic of the Baget stream water. The relative contributions of the karst and epikarst zones, of rainwater, as well as the role of different biogeochemical processes and the hydrological conditions were highlighted.https://www.mdpi.com/2673-4931/7/1/9carbonate dissolutionchemical weatheringwater chemistryflood eventshigh frequency monitoringhydrochemical survey |
spellingShingle | Francesco Ulloa-Cedamanos Anne Probst Vanessa Dos-Santos Jean-Luc Probst What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)? Environmental Sciences Proceedings carbonate dissolution chemical weathering water chemistry flood events high frequency monitoring hydrochemical survey |
title | What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)? |
title_full | What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)? |
title_fullStr | What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)? |
title_full_unstemmed | What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)? |
title_short | What Can Be Learned about the Relationships between Water Discharge and Composition during Flood Events in a Forested Karstic Catchment from the Pyrenees Mountains (Southwestern France)? |
title_sort | what can be learned about the relationships between water discharge and composition during flood events in a forested karstic catchment from the pyrenees mountains southwestern france |
topic | carbonate dissolution chemical weathering water chemistry flood events high frequency monitoring hydrochemical survey |
url | https://www.mdpi.com/2673-4931/7/1/9 |
work_keys_str_mv | AT francescoulloacedamanos whatcanbelearnedabouttherelationshipsbetweenwaterdischargeandcompositionduringfloodeventsinaforestedkarsticcatchmentfromthepyreneesmountainssouthwesternfrance AT anneprobst whatcanbelearnedabouttherelationshipsbetweenwaterdischargeandcompositionduringfloodeventsinaforestedkarsticcatchmentfromthepyreneesmountainssouthwesternfrance AT vanessadossantos whatcanbelearnedabouttherelationshipsbetweenwaterdischargeandcompositionduringfloodeventsinaforestedkarsticcatchmentfromthepyreneesmountainssouthwesternfrance AT jeanlucprobst whatcanbelearnedabouttherelationshipsbetweenwaterdischargeandcompositionduringfloodeventsinaforestedkarsticcatchmentfromthepyreneesmountainssouthwesternfrance |