TY - JOUR

T1 - Seasonal variation in phosphorus concentration–discharge hysteresis inferred from high-frequency in situ monitoring

AU - Bieroza, Magdalena

AU - Heathwaite, Louise

N1 - This is the author’s version of a work that was accepted for publication in Journal of Hydrology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Hydrology, 524, 2015 DOI: 10.1016/j.jhydrol.2015.02.036 Evidence of Acceptance: Date of Acceptance is on publishers version of paper. -------- Original message -------- From: "J. Hydrology" Date:20/02/2015 15:44 (GMT+01:00) To: "Bieroza, Magdalena" ,magdalena.bieroza@gmail.com Cc: bibhash12@gmail.com Subject: HYDROL16642R2: Editor's decision: accepted Dear Dr. Bieroza, I am pleased to inform you that the manuscript "Seasonal variation in phosphorus concentration-discharge hysteresis inferred from high-frequency in situ monitoring" (Dr. Magdalena Bieroza) has now been accepted for publication. Your manuscript will soon be passed to the production department for further handling. Then you will receive further notice. When your paper is published on ScienceDirect, you want to make sure it gets the attention it deserves. To help you get your message across, Elsevier has developed a new, free service called AudioSlides: brief, webcast-style presentations that are shown (publicly available) next to your published article. This format gives you the opportunity to explain your research in your own words and attract interest. You will receive an invitation email to create an AudioSlides presentation shortly. For more information and examples, please visit http://www.elsevier.com/audioslides. Thank you for considering our journal for the publication of your research. With kind regards, Laurent Charlet Editor Journal of Hydrology

PY - 2015/5

Y1 - 2015/5

N2 - High-resolution in situ total phosphorus (TP), total reactive phosphorus (TRP) and turbidity (TURB) time series are presented for a groundwater-dominated agricultural catchment. Meta-analysis of concentration–discharge (c–q) intra-storm signatures for 61 storm events revealed dominant hysteretic patterns with similar frequency of anti-clockwise and clockwise responses; different determinands (TP, TRP, TURB) behaved similarly. We found that the c–q loop direction is controlled by seasonally variable flow discharge and temperature whereas the magnitude is controlled by antecedent rainfall. Anti-clockwise storm events showed lower flow discharge and higher temperature compared to clockwise events. Hydrological controls were more important for clockwise events and TP and TURB responses, whereas in-stream biogeochemical controls were important for anti-clockwise storm events and TRP responses. Based on the best predictors of the direction of the hysteresis loops, we calibrated and validated a simple fuzzy logic inference model (FIS) to determine likely direction of the c–q responses. We show that seasonal and inter-storm succession in clockwise and anti-clockwise responses corroborates the transition in P transport from a chemostatic to an episodic regime. Our work delivers new insights for the evidence base on the complexity of phosphorus dynamics. We show the critical value of high-frequency in situ observations in advancing understanding of freshwater biogeochemical processes.

AB - High-resolution in situ total phosphorus (TP), total reactive phosphorus (TRP) and turbidity (TURB) time series are presented for a groundwater-dominated agricultural catchment. Meta-analysis of concentration–discharge (c–q) intra-storm signatures for 61 storm events revealed dominant hysteretic patterns with similar frequency of anti-clockwise and clockwise responses; different determinands (TP, TRP, TURB) behaved similarly. We found that the c–q loop direction is controlled by seasonally variable flow discharge and temperature whereas the magnitude is controlled by antecedent rainfall. Anti-clockwise storm events showed lower flow discharge and higher temperature compared to clockwise events. Hydrological controls were more important for clockwise events and TP and TURB responses, whereas in-stream biogeochemical controls were important for anti-clockwise storm events and TRP responses. Based on the best predictors of the direction of the hysteresis loops, we calibrated and validated a simple fuzzy logic inference model (FIS) to determine likely direction of the c–q responses. We show that seasonal and inter-storm succession in clockwise and anti-clockwise responses corroborates the transition in P transport from a chemostatic to an episodic regime. Our work delivers new insights for the evidence base on the complexity of phosphorus dynamics. We show the critical value of high-frequency in situ observations in advancing understanding of freshwater biogeochemical processes.

KW - High-frequency in situ nutrient monitoring

KW - Phosphorus

KW - Turbidity

KW - Groundwater-fed rivers

KW - Hyporheic zone

KW - Fuzzy inference system

U2 - 10.1016/j.jhydrol.2015.02.036

DO - 10.1016/j.jhydrol.2015.02.036

M3 - Journal article

VL - 524

SP - 333

EP - 347

JO - Journal of Hydrology

JF - Journal of Hydrology

SN - 0022-1694

ER -