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