Towards operational hydrology for a thorough spatio-temporal exploration of the Critical Zone
Résumé
Over the last century, the Critical Zone faced remarkable climate and land use changes increasing the pressures on
the Hydrosphere and giving rise to numerous environmental consequences in terms of water quantity and quality.
From now on, the Critical Zone must face the challenge to supply 9 billion people with quality food and safe
drinking water in a context of global warming. For the Hydrosphere, this challenge could be addressed with a
better understanding of the dynamics and resilience of aquatic environments (rivers, lakes, groundwaters, oceans).
In view of the spatial and temporal variety and variability of flow dynamics and biogeochemical reactions occur-
ring in the Hydrosphere a new investigation method is needed. This study approaches the concept of “operational
hydrology” aiming to enhance either the spatio-temporal distribution and the quality of environmental data for a
thorough exploration of the Hydrosphere.
To illustrate our approach, we present natural and anthropogenic dissolved gas data (He, Ne, Ar, Kr, Xe, N2, O
2
,
CO
2
, CH4, N2O, H2, BTEX, and some VOCs) measured in situ with a CF-MIMS (Chatton et al, 2016) installed
in a mobile laboratory arranged in an all-terrain truck (CRITEX-Lab). This ongoing work focuses on groundwater
and the field investigation of residence time distributions, recharge processes (origins), water flow paths and
mixing, biogeochemical reactivity and contamination (sources).
The rationale behind “operational hydrology” could be applied to the field measurement at high-frequency of
many other environmental parameters (temperature, cations, anions, isotopes, micro-organisms) not only for the
investigation of groundwaters but also rivers, lakes and oceans.
Eliot Chatton, Thierry Labasque, Jerome de La Bernardie, Nicolas Guihe neuf, Olivier Bour and Luc
Aquilina; Field Continuous Measurement of Dissolved Gases with a CF-MIMS: Applications to the Physics and
Biogeochemistry of Groundwater Flow; Environmental Science & Technology, in press, 2016.