Articles | Volume 18, issue 9
Hydrol. Earth Syst. Sci., 18, 3429–3448, 2014
Hydrol. Earth Syst. Sci., 18, 3429–3448, 2014

Research article 08 Sep 2014

Research article | 08 Sep 2014

High-frequency monitoring of nitrogen and phosphorus response in three rural catchments to the end of the 2011–2012 drought in England

F. N. Outram1, C. E. M. Lloyd2, J. Jonczyk3, C. McW. H. Benskin4, F. Grant5, M. T. Perks6, C. Deasy6,4, S. P. Burke7, A. L. Collins8,9, J. Freer2, P. M. Haygarth4, K. M. Hiscock1, P. J. Johnes2, and A. L. Lovett1 F. N. Outram et al.
  • 1School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7T, UK
  • 2School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
  • 3School of Civil Engineering and Geosciences, Cassie Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
  • 4Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK
  • 5ADAS, Pendeford House, Pendeford Business Park, Wobaston Road, Wolverhampton WV9 5AP, UK
  • 6Department of Geography, Durham University, Durham DH1 3LE, UK
  • 7British Geological Survey, Keyworth, Nottingham NG125GG, UK
  • 8Sustainable Soils and Grassland Systems Department, Rothamsted Research-North Wyke, Okehampton, EX20 2SB, UK
  • 9Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK

Abstract. This paper uses high-frequency bankside measurements from three catchments selected as part of the UK government-funded Demonstration Test Catchments (DTC) project. We compare the hydrological and hydrochemical patterns during the water year 2011–2012 from the Wylye tributary of the River Avon with mixed land use, the Blackwater tributary of the River Wensum with arable land use and the Newby Beck tributary of the River Eden with grassland land use. The beginning of the hydrological year was unusually dry and all three catchments were in states of drought. A sudden change to a wet summer occurred in April 2012 when a heavy rainfall event affected all three catchments. The year-long time series and the individual storm responses captured by in situ nutrient measurements of nitrate and phosphorus (total phosphorus and total reactive phosphorus) concentrations at each site reveal different pollutant sources and pathways operating in each catchment. Large storm-induced nutrient transfers of nitrogen and or phosphorus to each stream were recorded at all three sites during the late April rainfall event. Hysteresis loops suggested transport-limited delivery of nitrate in the Blackwater and of total phosphorus in the Wylye and Newby Beck, which was thought to be exacerbated by the dry antecedent conditions prior to the storm. The high rate of nutrient transport in each system highlights the scale of the challenges faced by environmental managers when designing mitigation measures to reduce the flux of nutrients to rivers from diffuse agricultural sources. It also highlights the scale of the challenge in adapting to future extreme weather events under a changing climate.