title: High-frequency water quality time series in precipitation and streamflow: from fragmentary signals to scientific challenge.
abstract: Eighteen months of 7-hourly analyses of rainfall and stream water chemistry are presented, spanning a wide range of chemical determinands and building on over 20 years of weekly records for the moorland headwaters of the river Severn. The high-frequency time series data show that hydrochemical responses to major hydrological and biological drivers of short-term variability in rainfall and rivers are not captured by conventional low-frequency monitoring programmes. A wealth of flow related, flow independent, diurnal, seasonal and annual fluctuations indicate a cacophony of interactions within the catchment and stream. The complexity of the chemical dynamics is visually obvious, although there appears to be no clear way of translating this complexity into a simple algorithm. The work provides a proof of concept for the complex structure of catchment functioning revealed by extensive high-frequency measurements coupled with high analytical sensitivity and reproducibility. It provides new insights into hydrogeochemical functioning and a novel resource for catchment modelling.
authors.affiliation: Centre for Ecology and Hydrology, Wallingford, Crowmarsh Gifford, Oxon, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Neal
authors.forename: Brian
authors.initials: B
authors.lastname: Reynolds
authors.forename: Philip
authors.initials: P
authors.lastname: Rowland
authors.forename: David
authors.initials: D
authors.lastname: Norris
authors.forename: James W
authors.initials: JW
authors.lastname: Kirchner
authors.forename: Margaret
authors.initials: M
authors.lastname: Neal
authors.forename: Darren
authors.initials: D
authors.lastname: Sleep
authors.forename: Alan
authors.initials: A
authors.lastname: Lawlor
authors.forename: Clive
authors.initials: C
authors.lastname: Woods
authors.forename: Sarah
authors.initials: S
authors.lastname: Thacker
authors.forename: Hayley
authors.initials: H
authors.lastname: Guyatt
authors.forename: Colin
authors.initials: C
authors.lastname: Vincent
authors.forename: Kathryn
authors.initials: K
authors.lastname: Hockenhull
authors.forename: Heather
authors.initials: H
authors.lastname: Wickham
authors.forename: Sarah
authors.initials: S
authors.lastname: Harman
authors.forename: Linda
authors.initials: L
authors.lastname: Armstrong
mesh_terms: D004784:Environmental Monitoring; D011786:Quality Control; D011891:Rain; D014872:Water Movements; D060753:Water Quality