Water age and stream solute dynamics at the Hubbard Brook Experimental Forest (US)

TitleWater age and stream solute dynamics at the Hubbard Brook Experimental Forest (US)
Publication TypeConference Paper
Year of Publication2016
AuthorsBotter, G, Benettin, P, McGuire, KJ, Rinaldo, A
Conference NameEGU General Assembly Conference Abstracts
Date Published2016/04/01/

The contribution discusses experimental and modeling results from aheadwater catchment at the Hubbard Brook Experimental Forest (New
Hampshire, USA) to explore the link between stream solute dynamics and
water age. A theoretical framework based on water age dynamics, which
represents a general basis for characterizing solute transport at the
catchment scale, is used to model both conservative and
weathering-derived solutes. Based on the available information about the
hydrology of the site, an integrated transport model was developed and
used to estimate the relevant hydrochemical fluxes. The model was
designed to reproduce the deuterium content of streamflow and allowed
for the estimate of catchment water storage and dynamic travel time
distributions (TTDs). Within this framework, dissolved silicon and
sodium concentration in streamflow were simulated by implementing
first-order chemical kinetics based explicitly on dynamic TTD, thus
upscaling local geochemical processes to catchment scale. Our results
highlight the key role of water stored within the subsoil glacial
material in both the short-term and long-term solute circulation at
Hubbard Brook. The analysis of the results provided by the calibrated
model allowed a robust estimate of the emerging concentration-discharge
relationship, streamflow age distributions (including the fraction of
event water) and storage size, and their evolution in time due to
hydrologic variability.