Slide 1

High-resolution monitoring of diffuse pollution effects in the River Eden catchment, UK

Dr Ben SurridgeLancaster Environment Centre, Lancaster University

PPM-nutrients workshop, Beijing, China, 25-26th February 20141Defra Demonstration Test Catchment Platform

Wensum(Norfolk)

Arable farmingConsortium includes:University of East Anglia, Scott Wilson, Cranfield University, British Geological Survey, Entec, NIAB and others...

Avon(Hampshire)

Mixed lowland farmingConsortium includes:ADAS, University of Reading, University of Bristol, QMUL, ENTEC and others...

Eden(Cumbria)

Livestock and mixed farmingConsortium includes:Lancaster University, Newcastle University, Durham University, Newton Rigg, Eden Rivers Trust, CEH and others...

Three catchments representative of major UK agricultural production systems

2Eden Demonstration Test Catchment (DTC)

2000 km2

3EdenDTC

3* 10 km2

4EdenDTC

3* 10 km2

5An integrated monitoring platformCombining data from the same location at high-frequency:

Water qualityDischargeBiological quality

Make the clear points about needing an integrated monitoring in space if were to understand a system and the cause-effect relationships related to environmental impacts of diffuse pollution.

Make the point about high-frequency measurements for system understanding6

Quantifying annual/seasonal patterns in load and concentrationAutumn/winter 2011/2012Spring 2012Summer 2012Make the clear points about needing an integrated monitoring in space if were to understand a system and the cause-effect relationships related to environmental impacts of diffuse pollution.

Make the point about high-frequency measurements for system understanding7Understanding concentration and load patternsWet summer 2012 significantly impacts total load and seasonal distribution of load

Annual concentration-discharge relationships lead to hypotheses about sources of nutrients

Important of high-frequency annual data for load estimation

Also important for understanding behaviour of the system in this case likely sources of reactive P (diffuse)8

Make the clear points about needing an integrated monitoring in space if were to understand a system and the cause-effect relationships related to environmental impacts of diffuse pollution.

Make the point about high-frequency measurements for system understanding9Understanding event-scale responses

Autumn/winter eventSummer eventHypothesis: changes in nitrate source between autumn and summer runoff eventsSources/pathways change at sub-annual scales?

Interesting with nitrate peak in summer high flow, usually diluted. Possible agricultural sources, e.g. fertiliser app followed by runoff?

Generating hypotheses that can be tested experimentally.10Looking inside a runoff eventHysteresis in concentration-discharge relationships

For TRP higher concentration on the falling compared to rising limb

Hypothesis: transport-limited source of P drives TRP, not source-exhaustion

Outram et al. (In review) HESS Biological effects of chemical water quality

Benthic biofilm used as a bioindicator, particularly the diatom community

Sensitive to nutrient availability (P, Si)

Sensitive to variation in river discharge

Links between water quality and biological response in streams key for legislation and for food web linkages12Biological effects of chemical water quality

Seasonal variability in descriptors of benthic diatom communityHypotheses: a response to seasonal changes in water quality or river dischargeLinks between water quality and biological response in streams key for legislation and for food web linkages13