The hydrological response of heavy clay grassland soils to rainfall in south-west England using δ2H
Granger, Steven J.; Bol, Roland; Meier-Augenstein, Wolfram; Leng, Melanie J.; Kemp, Helen F.; Heaton, Tim H.E.; White, Sue M.. 2010 The hydrological response of heavy clay grassland soils to rainfall in south-west England using δ2H. Rapid Communications in Mass Spectrometry, 24 (5). 475-482. 10.1002/rcm.4281Full text not available from this repository. (Request a copy)
Stable isotopes of water have been previously used in catchment studies to separate rain-event water from pre-event groundwater. However, there are a lack of studies at the smaller scale looking at the separation of event water from pre-event water. This is particularly relevant for heavy clay soil systems through which the movement of water is uncertain but is thought to be rainwater-dominated. The data presented here were collected at a rural site in the south-west of England. The historic rainfall at the site was isotopically varied but similar to the global meteoric water line, with annual weighted means of -37 for 2H and -5.7 for 18O and with no seasonal variation. Drainage was sampled from the inter-flow (surface runoff + lateral through-flow) and drain-flow (55 cm deep mole drains) pathways of two 1 ha lysimeters during two rainfall events, which had 2H values of -68 and -92 , respectively. The 2H values of the lysimeter drainage water suggest that there was no contribution of event water during the first, small discharge (Q) event; however, the second larger event did show isotopic variation in 2H values negatively related to Q indicating that rainwater was contributing to Q. A hydrograph separation indicated that only 49-58% of the inter-flow and 18-25% of the drain-flow consisted of event water. This was surprising given that these soil types are considered retentive of soil water.
|Programmes:||BGS Programmes 2010 > NERC Isotope Geoscience Laboratory|
|NORA Subject Terms:||Agriculture and Soil Science|
|Date made live:||15 Apr 2010 08:56|
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