Characterising phosphorus and nitrate inputs to a rural river using high-frequency concentration-flow relationships

M. J. Bowes, H. P. Jarvie, S. J. Halliday, R. A. Skeffington, A. J. Wade, M. Loewenthal, E. Gozzard, J. R. Newman, E. J. Palmer-Felgate

    Research output: Contribution to journalArticlepeer-review

    137 Citations (Scopus)
    308 Downloads (Pure)

    Abstract

    The total reactive phosphorus (TRP) and nitrate concentrations of the River Enborne, southern England, were monitored at hourly interval between January 2010 and December 2011. The relationships between these high-frequency nutrient concentration signals and flow were used to infer changes in nutrient source and dynamics through the annual cycle and each individual storm event, by studying hysteresis patterns. TRP concentrations exhibited strong dilution patterns with increasing flow, and predominantly clockwise hysteresis through storm events. Despite the Enborne catchment being relatively rural for southern England, TRP inputs were dominated by constant, non-rain-related inputs from sewage treatment works (STW) for the majority of the year, producing the highest phosphorus concentrations through the spring-summer growing season. At higher river flows, the majority of the TRP load was derived from within-channel remobilisation of phosphorus from the bed sediment, much of which was also derived from STW inputs. Therefore, future phosphorus mitigation measures should focus on STW improvements. Agricultural diffuse TRP inputs were only evident during storms in the May of each year, probably relating to manure application to land. The nitrate concentration-flow relationship produced a series of dilution curves, indicating major inputs from groundwater and to a lesser extent STW. Significant diffuse agricultural inputs with anticlockwise hysteresis trajectories were observed during the first major storms of the winter period. The simultaneous investigation of high-frequency time series data, concentration-flow relationships and hysteresis behaviour through multiple storms for both phosphorus and nitrate offers a simple and innovative approach for providing new insights into nutrient sources and dynamics.

    Original languageEnglish
    Pages (from-to)608-620
    Number of pages13
    JournalScience of the Total Environment
    Volume511
    Early online date14 Jan 2015
    DOIs
    Publication statusPublished - 1 Apr 2015

    Keywords

    • Diffuse source
    • Eutrophication
    • Hysteresis
    • Nutrient dynamics
    • Point source
    • Source tracking

    Fingerprint

    Dive into the research topics of 'Characterising phosphorus and nitrate inputs to a rural river using high-frequency concentration-flow relationships'. Together they form a unique fingerprint.

    Cite this