Sala de Graus II
Facultat de Ciències i Biociències, Edifici C
UAB Campus de Bellaterra
Cerdanyola del Vallès
Espanya

Seminar: "Understanding water storage, mixing and travel times in soils using water stable isotopes"

dimarts, març 14, 2017 15h

UNDERSTANDING WATER STORAGE, MIXING AND TRAVEL TIMES IN SOILS USING WATER STABLE ISOTOPES

Seminar by Mattias Sprenger, from the School of Geosciences, Geography & Environment, University of Aberdeen.

Soils play a central role in water partitioning into evaporation, transpiration and recharge fluxes. I present how stable isotopes (d2H and d18O) of soil water can help to assessing soil evaporation dynamics, interpreting plant water uptake pattern, and inferring groundwater recharge fluxes.

On the one hand, the presented field observations of soil water isotopes under different environmental conditions allow direct interpretations of how water is mixed, stored, released to the atmosphere or percolating to the groundwater. The isotope data emphasizes how variable these processes in the subsurface are in space (e.g., soil depth) and time (e.g., seasonality) and I will discuss the implications regarding plant water uptake in ecohydrological studies.
On the other hand, the sampled soil water isotope data can be used for calibrating soil hydraulic models. Taking the isotopic tracer – in addition to hydrometric data (e.g., soil moisture) - into account allows to simulate in addition to the hydraulic response (e.g., change of soil moisture due to rainfall event, celerity) also the water transport (e.g., advection and dispersion of water, velocity). This way, we can trace water through the soil-plant-atmosphere continuum and determine travel times of evaporation, transpiration and recharge. I will present how variable these travel times are in space and time and what this means for catchment hydrology and groundwater contamination.

Sprenger, M., H. Leistert, K. Gimbel, and M. Weiler (2016), Illuminating hydrological processes at the soil-vegetation-atmosphere interface with water stable isotopes, Rev. Geophys., 54, 674–704, doi:10.1002/2015RG000515.