About the Project
Fluvial system sustainability is vital for a half billion riparian residents of global river floodplains and deltas, and it requires knowledge and understanding of the land surface changes through time in response to anthropogenic and climatic forcing. Germane to such understanding is high quality topographic data enabling the quantification of surface morphology and change, which are essential for understanding responses of lowland sedimentary systems to these forcings.
However, most topographic data are of insufficient quality and resolution, creating major challenges for managing lowland river-floodplain complexes in large alluvial rivers. This scarcity of topographic data is especially applicable to low-gradient tropical rivers where 1) accurate topographic survey data are scarce, 2) floodplains have significant vegetation precluding satellite observation of surfaces, and 3) previous global data (eg., SRTM) are technically limited in terms of accuracy and resolution for geomorphic applications. The TanDEM-X high-resolution SAR mission (directory.eoportal.org/web/eoportal/satellite-missions/t/tandem-x) offers a way forwards, especially when paired with remote sensing data and machine learning statistical methods.
Our exploratory work with the high-resolution (~12m) TDX product in Amazonia and SE Asia has identified means to remove trees using a combination of tomographic analysis, remote sensing, and machine learning – producing bare earth DEMs for fluvial systems that can be verified for locations where we have field survey and Lidar data from prior and current NERC, NSF, and NASA-funded research projects.
The PhD student would focus on the refinement and application of these novel data and techniques towards quantifying the topography and evolution of project rivers – the lower Mekong River and large portions of the Amazon, major river systems that can be used to calibrate and test these approaches in coordination with ongoing NERC-funded research. Following this verification and refinement against available data, the student would work with the supervisorial team to identify and pursue a range of intriguing scientific questions for apt research locations, providing the PhD candidate flexibility and intellectual independence to realize their own interests and opportunities for transformative research.
The project will appeal to candidates skilled with GIS analysis of topographic datasets, and who are interested in novel spatial analysis of the expressions of and controls on large river morphodynamics – candidates are encouraged to contact the lead supervisor to discuss specific scientific and technical questions for this PhD research.
Exeter is a Russel Group research-intensive university located in a beautiful semi-rural setting, yet just two hours by train from London. We are an international leader in environmental research, Geography is ranked in the top 5 globally (ARWU 2020), and we have close links to the MET Office/Hadley Centre’s climate research into river systems that offers additional opportunities for the prospective student.
Project Aims and Methods:
After refining the analytical methods for study areas with suitable field data, the PhD research would focus on quantifying the floodplain topography and gradients that drive flow, sediment transport, and river evolution for research sites, providing novel scientific insight into the functioning of fluvial systems. To further evaluate observed relationships, the student would work closely with the supervisorial team to design the reminder of their PhD research. For example, potential causal mechanisms identified for study rivers could be tested using models for fluvial morphodynamics (both standard and Exeter research models). Measurements and predictions could be verified against extensive Exeter field datasets available for the study systems and elsewhere, with possibilities for fieldwork. The ultimate aim of this PhD will be to produce generic findings about the functioning and complex evolution of large river systems that are suitable for publication in prominent journals, preparing the student for further career success.
Candidate Requirements:
Strong skills for topographic analysis and remote sensing are required. Modelling and coding skills would also be beneficial, along with a demonstrated passion for river science.
Training:
We will provide a high spec workstation plus training for analysing project data. Exeter provides expert technical support for GIS, specialist software such as Delft-FM, HSTAR, and other massively parallel models, and the necessary computer resources to run them. There may be opportunities for the student to assist with NERC-funded survey(s) of river bed and floodplain topography along the Amazon and Mekong Rivers.
Useful Links:
https://geography.exeter.ac.uk/staff/index.php?web_id=Rolf_Aalto
http://geography.exeter.ac.uk/staff/index.php?web_id=Barend_Van-Maanen
http://geography.exeter.ac.uk/staff/index.php?web_id=Andrew_Nicholas
https://www.cardiff.ac.uk/people/view/808751-singer-michael
Prospective applicants:
For information about the application process please contact the Admissions team via [Email Address Removed]
Each research studentship project advertisement has an ‘Apply Now’ button linking to an application portal. Please note that applications received via other routes including a standard programme application route will not be considered for the studentship funding.
Funding Notes
NERC GW4+ funded studentship available for September 2021 entry. For eligible students, the studentship will provide funding of fees and a stipend which is currently £15,285 per annum for 2020-21.