nerc.ac.uk

Revealing groundwater discharge to a lowland wetland by combining temperature and vegetation surveys

House, Andrew; Sorensen, James; Gooddy, Daren; Marchant, Benjamin; Newell, Andrew; Old, Gareth; Roberts, Colin; Scarlett, Peter. 2013 Revealing groundwater discharge to a lowland wetland by combining temperature and vegetation surveys. [Lecture] In: Wetland Hydrology: BHS National Meeting, Birmingham, UK, 13 Sept 2013. (Unpublished)

Full text not available from this repository. (Request a copy)

Abstract/Summary

Understanding of wetlands is vital for conservation management and evaluating the impacts of climate change and groundwater abstraction. The Lambourn Observatory at Boxford comprises a 10 ha SSSI designated water meadow. A layer of up to 2.7 m of peat covers up to 7.5 m of coarse-grained gravel alluvium, underlain by Chalk. Previous investigations using an arbitrary piezometer array and chemistry have suggested a northern dependency on river stage and southern dependency on groundwater contributions. However, groundwater inflows to wetlands can be discrete and easily missed. Spatial surveys are necessary to ensure sites are adequately conceptualised. We rapidly characterised the site using temperature and vegetation over 2 weeks. Temperature data were collected in winter at multiple depths down to 0.9 m at over 1000 locations. Temperature ranged from ~10 °C to ~2 °C, with anomalous warm hotspots and relatively constant temperature gradients indicating areas of groundwater contribution. Botanical indicators of groundwater were identified from a vegetation survey and available literature. The distribution of Carex paniculata (Greater tussock sedge) corresponded to temperature anomalies, whilst Alisma plantago-aquatica (Water plantain) matched areas of constant surface flow fed by springs. Hydraulic heads and groundwater chemistry from a new targeted piezometer array provided corroborating information which supported designation of the temperature anomalies as zones of groundwater discharge.

Item Type: Publication - Conference Item (Lecture)
CEH Sections: Acreman
Additional Keywords: GroundwaterBGS, Groundwater, Surface water interaction, Groundwater thermometry
NORA Subject Terms: Hydrology
Date made live: 11 Nov 2013 11:42 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/503673

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...