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A presentation by Dr Gareth Old of the Centre for Ecology & Hydrology (CEH) on monitoring work at the CEH River Lambourn Observatory and research into chalk river systems.
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CEH RIVER LAMBOURN OBSERVATORY
Dr Gareth Old A. House, C. Stratford, C. Roberts, J. Sorensen, D. Gooddy, A. Newell, B. Marchant, O. Mountford, P. Scarlett, R. Ponnambalam, P. Williams and J. Chambers
CHALK STREAMS
• High quality designated habitat; diverse ecology• Stable flows, clear waters, constant temperature, and
low nutrients/sediments• Long time ago very different!• Current chalk streams are heavily modified• Return to pristine landscape not possible• Management is a challenge
Monthly Flow Values, Boxford
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Jul 08 Aug08
Sept08
Oct 08 Nov08
Dec08
Jan09
Feb09
Mar09
Apr 09 May09
Jun09
Cu
me
c
Winter Period
Peak flow
BOXFORD FLOW REGIME
Widespread agricultural systems: 18th C
Managed water levels (SW and GW) : soil moisture, temp. and fertility
Widespread abandonment in 20th C
Many now recognised as important GDE’s
Concern in WFD - vulnerable to environmental change
Many are now degrading: restore/conserve
WATER MEADOWS
BOXFORD WATER MEADOW
• Desmoulin’s whorl snail• MG8 veg community
Designated SSSI and SACCondition assessment:
“Scrub is beginning to encroach … will need to be addressed shortly to … avoid site becoming unfavourable”.Natural England July 2008
RESEARCH: HYDROLOGICAL FUNCTIONING
• Survey and monitor to model the site– Developed new non-invasive techniques– Conceptual and numerical
• Inform management, monitoring and enable assessment of scenarios
TOPOGRAPHY
SUBSURFACE GEOLOGY
Manual probingBorehole logsElectro resistivity tomography
METEOROLOGICAL INPUTS
GROUNDWATER INPUTS
Temperature and chemistry
GROUNDWATER INPUTS
INFLUENCE OF THE RIVER
RIVER DISCHARGE
GROUNDWATER LEVELS
GROUNDWATER LEVELS
CONCLUDING REMARKS
CEH River Lambourn Observatory
Monitoring and surveying• Non-invasive, low cost and rapid• Information versus investment• Conceptual and numeric model development
Test scenarios
Results and methods: applicable to other sites