Can we predict the effects of climate induced flood events on the mobility and bioaccessibility of potentially harmful elements?

Overview

Climate change is likely to have an influence on the lives of every citizen in the world. A key anticipated impact is an increase in extreme weather events, with a corresponding higher frequency of severe weather events, particularly flooding [1] (e.g. Figure 1). Depending on frequency and magnitude, flooding can be either beneficial or detrimental, e.g. it can maintain or enhance soil fertility by depositing fresh layers of alluvium and flushing salts out, or it can increase the mobility of potentially harmful elements (PHEs), originating from natural or anthropogenic sources. Flood-waters can redistribute PHEs from soils and sediments, resulting in increased exposure for humans and wildlife, as seen in the aftermath of Hurricane Katrina [2]. Human exposure may occur via direct ingestion, dermal contact and inhalation and contaminant transfer to foodstuffs and is increasingly a problem [3].

Recent findings have shown flooding-induced increases in contamination levels in soils and pore-water after flooding [3]. However, most studies only consider absolute PHE concentrations, leaving considerable scope for improving our understanding of biogeochemical processes occurring during and after flood events.

Understanding the key biogeochemical processes related to contaminant mobility and redistribution during flooding events will have local, national and international impact, from the provision of advice and information to people growing food in urban allotments etc. where flooding may occur through to evolution of the landscape itself, and to providing improved understanding of the risks associated with flooding, thus providing an input into the wider debate on the significance of climate change.

This research will also input into the work of policy makers, land owners, regulators and risk assessors by helping them better understand the role of biogeochemical processes in floodplains as well as considering their impacts on human health, soil health and the environment.

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Image Captions

Figure 1: Flooding of urban and industrial areas and surrounding land used for food production. Source: BGS

Methodology

The project will test the hypothesis that soil flooding associated with climate change will cause ecological and human health impacts from PHE (re)mobilisation (e.g. on soil health through measures of soil function).

Utilising national data geochemical and flood risk data sets and newly generated data on biogeochemical processes, the risks of PHE remobilisation under different saturation, flow and biological conditions will be predicted and, using suitable field locations, field- and laboratory-based experiments will be undertaken to corroborate the modelling work. The Landscape Evolution Modelling (LEM) provides a tool for quantifying fluvial flows and levels, and sediment transport rates across a catchment. Fluvial flow rates can be calibrated and validated against observed data. We will use the well-established CAESAR-LF LEM to give us a continuous sediment and water flux rates over many decades and to track the distribution of sediment. Simulated flooding events in the field along with associated laboratory batch experiments will further determine contaminant mobility.

Opportunities exist for the student to spend time at BGS Nottingham to be trained in analytical and modelling methods.

Project Timeline

Year 1

Funding is available for 3.5 years.

Time will be spent understanding the biogeochemical processes that are influenced by flooding by:

Conducting a literature review and designing an appropriate research strategy for the field and laboratory studies;

Making predictions of flooding induced impacts in different catchments across the UK (training in both analytical (Prof Copplestone and Dr Wragg) and modelling techniques in landscape evolution will be provided by Drs Palumbo-Roe and Barkwith) in year 1.

Participate in BGS annual conference.

Year 2

Year 2 will focus on implementing the planned field and laboratory studies. In particular, by testing the model predictions on the fate and behaviour of PHEs in different catchments and then the models will be refined given the new field and laboratory data.

Participate in BGS annual conference.

Start writing up the first chapters on the literature and modelling predictions.

Year 3

Continue to improve model predictions using the new field/laboratory data and by making spatial predictions of risks from flood mobilisation of potentially harmful elements for catchments not included in the initial study.

Participate in BGS annual conference & one international conference.

Continue to write up with the intention to have 2-3 chapters finished by the end of year 3.

Year 3.5

Thesis finalisation and paper writing (although it is anticipated that these activities will be ongoing throughout the PhD).

Training
& Skills

The analytical and modelling techniques required for this study are established within the University of Stirling and BGS.

The student will receive training in experimental design, chemical analysis, data analysis, predictive modelling techniques, on how to use CAESAR-LF and methods for hydrological calibration and validation, fieldwork, effective writing and presentation skills at both organisations. The student will benefit from wider interaction within research groups at Stirling, the BGS and the wider IAPETUS2 training programme with personal development opportunities available through both organisations and will be eligible for NERC-funded training courses.

The student will be expected to present their results annually at BGS science events and the Biological and Environmental Sciences student symposium. The student will also have the opportunity to present their work at an international conference.

References & further reading

Abel et al. 2010. Environ. Geochem. Health 32, 379-389
Environment Agency. 2009. Science Report SC050021/SR3
Solomon et al. 2007. Climate Change 2007
https://www.bgs.ac.uk/research/GBMG/medicalGeology.html
https://www.bgs.ac.uk/research/environmentalmodelling/processModelling.html

Further Information

Further information and informal discussions can be held with either:

David Copplestone: 01786 467852 (david.copplestone@stir.ac.uk)
Joanna Wragg: 01159363069 (jwrag@bgs.ac.uk)

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