PhD: Rethinking the hydrology of drained agricultural catchments based on insights from natural abundance stable isotopes of water via FindAPhD

University of Leicester

Leicester, UK 🇬🇧

About the Project

Project Highlights:

  • This project will attempt to improve understanding of the hydrology of drained catchments by monitoring the behaviour of natural tracers and pesticides.
  • You will instrument and monitor a drained catchment using high frequency sampling and analysis using state of the art laboratory facilities.
  • You will gain insights into hydrological and solute transport processes using off-the-shelf and bespoke modelling tools.

Overview:

Artificial field drains are installed under approximately 30% of UK agricultural land. These drains maintain water table depths at levels which allow increased yields in heavy soils. However, they also act as conduits for the transfer of water from land to surface waters and they are known to be important pathways for pollutant transport, such as pesticides. However, our current understanding of both water and solute dynamics in drained catchments has largely been derived prior to recent advances in hydrological insight gained via the application of natural tracers such as the stable isotopes of water. This work has shown that the hydrological response of stream discharge to rainfall is often much faster than the mean transit time for water. Moreover, stream water often has a tracer signature characteristic of “old” (pre-event) water (in soil and or groundwater) with relatively little contribution of “new” (event) water (i.e. with a tracer signature similar to rainwater). The modulation of tracer variability in precipitation to that in streamflow is mainly due to physical mixing processes and implies that water storage volumes are large and mean water residence times are long. Paradoxically, peak stream water pesticide concentrations are commonly observed during the first significant storm events after application – suggesting that some relatively new water (i.e. near-surface soil pore water which has mixed with pesticides) can make an immediate contribution to storm flow in drained catchments. There is a need, therefore, to disentangle this paradox and gain a more complete understanding of the behaviour of both natural tracers and pesticides in drained catchments.

In this project, we will investigate this problem by monitoring (simultaneously, at high frequency and at a number of locations) concentrations of pesticides and natural isotope tracers in soil water, drainflow and stream flow and concentrations of natural tracers in rainfall. These data will be used to develop a quantitative conceptual description of catchment dynamics which explains, simultaneously, patterns of stream discharge, natural tracer variations and pesticide concentrations and loads.

Academic entry requirements:

  • Applicants must have or expect to obtain a first class or upper second class BSc and/or M-level degree (or an equivalent overseas qualification) in a relevant subject.
  • University of Leicester English language requirements apply as necessary.

Informal enquiries/Contact details:

Mick Whelan – [email protected]

Arnoud Boom – [email protected]

For general enquiries please email [email protected]

How to apply

Please read carefully the application advice under the How to Apply section at https://le.ac.uk/study/research-degrees/funded-opportunities/centa-phd-studentships before submitting your application.

Eligibility

Applicants who meet or are expected to meet the academic entry requirements can apply.

To be eligible for a full (Home) award a student must have no restrictions on how long they can stay in the UK and have been ordinarily resident in the UK for at least 3 years prior to the start of the studentship.

If you do not meet the criteria for UK Fees you will need to fund the difference between UK and International fees for the duration of your studies. A limited number of top up studentships to fund the fee difference may become available but are not guaranteed.

If you are unsure of your fee status please email [email protected] and include a copy of your passport and any immigration permission you may hold.


Funding Notes

NERC CENTA studentships are for 3.5 years and are funded by NERC. In addition to the full payment of your tuition fees, you will receive the following financial support:
• Annual stipend, currently set at £15,285 (2020/1)
• Research training support grant (RTSG)
If you are not eligible for UK Fees you will need to be able to fund the difference between UK and International fees for the duration of your studies


References

Further reading:
Birkel C., Soulsby C. (2015) Advancing tracer‐aided rainfall–runoff modelling: a review of progress, problems and unrealised potential. Hydrological Processes 29, 5227-5240
Tediosi A., Whelan M.J., Rushton K.R., Thompson T.R.E., Gandolfi C. and Pullan S.P. (2012) Measurement and conceptual modelling of herbicide transport to field drains in a heavy clay soil with implications for catchment-scale water quality management. Science of the Total Environment 438, 103-112
Whelan M.J., Ramos A., Villa R., Guymer I., Jefferson B., Rayner M. (2020) A new conceptual model of pesticide transfers from agricultural land to surface waters with a specific focus on metaldehyde. Environmental Science: Processes and Impacts 22, 956 – 972


POSITION TYPE

ORGANIZATION TYPE

EXPERIENCE-LEVEL

DEGREE REQUIRED