Staff Profile

Professor Stuart Dunning

Professor of Applied Geomorphology

Telephone: +44 (0) 191 208 3251
Address: School of Geography, Politics and Sociology
Newcastle University
Newcastle upon Tyne
NE1 7RU

Current Projects

1. Chamoli. SUPERSLUG: Deconstructing sediment superslugs as a legacy of extreme flows (NERC PtF)

On 7th February 2021 a massive rock-ice avalanche originating from a mountain ridge in Chamoli District, Uttarakhand, Indian Himalaya, transformed into a fast-moving and catastrophic debris flow which travelled along the Rishiganga, Dhauliganga, and Alaknanda rivers. The flow killed hundreds of people, destroyed or damaged mature and under-construction hydropower projects, and caused severe modification to the channel and wider valley floor landscape, including the destabilising of steep valley sides. Once the flood subsided, rapid post-event analysis revealed that sediments deposited by the debris flow were more than 20 m thick in places, and that the flow was capable of transporting boulders exceeding 20 m in diameter. SUPERSLUG will push the frontiers of scientific knowledge and technical innovation to reveal new fundamental insights into the legacies of catastrophic sediment-rich flows (SRF) in mountain landscapes, such as landslides, rock-ice avalanches and glacial lake outburst floods. Catastrophic SRFs are hypothesised to become more frequent this century due to climate warming, and often affect vulnerable communities and assets in least developed countries the most. SRFs can entrain, mobilise, and deposit vast quantities of sediment, which can blanket valley floors to depths of tens of metres. The subsequent re-working and transport of these sediments by rivers can generate large-scale and fast-moving 'superslugs', which is a so-called 'legacy' impact of an SRF. Such legacy impacts are poorly understood, mostly due to observational challenges which have persisted for over a hundred years. However, improving our understanding of these impacts is of vital importance: enhanced fluvial transport of sediment following an SRF can affect flood hazard (by altering river channel bed elevation), infrastructure (e.g. by scouring bridge footings and damaging hydropower turbines), and can disrupt water quality, reducing water and energy security in regions that experience increasingly unstable and hazardous hydrological regimes. With SUPERSLUG we seek to encourage a paradigm shift framed around our argument that the landscape legacies of catastrophic SRFs should be quantified in as much detail as an initial event. To do this we will springboard from recent UKRI-funded pilot work by our international team to develop and apply a new multi-method and widely applicable suite of tools for quantifying the geomorphological evolution of SRF-affected catchments over multi-decade timeframes that are relevant for decision makers, in turn generating new insights into the fundamental behaviour, and impacts, of sediment superslugs. We will focus on a ~150 km-long exemplar system in the Indian Himalaya that has recently experienced a catastrophic SRF; the so-called 'Chamoli disaster'. This catchment arguably represents the most data-rich landscape of its type globally and sits within an otherwise extremely data-poor region. To deconstruct the evolution and impacts of sediment superslugs we will implement five work packages which will: (WP1) benchmark the geomorphological and sedimentological evolution of an SRF-affected system in space and time by using drone-derived observations to upscale from local- to catchment-wide observations using satellite remote sensing; (WP2) directly measure bedload motion in SRF-affected river channels using innovative wireless 'smart' cobbles, complemented with passive seismics; (WP3) develop an open-source toolkit for detecting and tracking fine-grained superslugs by leveraging cloud-based (Google Earth Engine) processing of free satellite imagery; and (WP4) integrate our novel observations from WP1-3 to upscale a powerful numerical landscape evolution-hydrodynamic model to simulate superslug mobility and the wider geomorphological evolution of our exemplar catchment. Our calibrated model, which will be a form of 'digital twin', will represent the largest of its kind and we will use it to explore catchment management decisions (e.g. HEP flushing schedules) for mitigating the worst superslug impacts. Underpinning these four WPs is a fifth WP, wherein we will adopt a Theory of Change-based approach for engaging closely with beneficiaries of this new knowledge and associated tools to translate our findings into practical outcomes and impact, including governance and disaster management professionals, hydropower operators and the wider international academic community.

2. Landslides in the U.K.

Over the past 5 years I have obtained funds to undertake high resolution monitoring of landslides that threaten the U.K. road and rail network (NERC Urgency; NERC Constructing a Digital Environment; Scottish Roads Research Board; Research England 'Pitch-In')

NERC CDE: Landslide Mitigation Informatics (LIMIT): Effective decision-making for complex landslide geohazards.

Landslides or the threat of landslides can cause significant economic disruption and pose a risk to life. Relatively small events can affect wide areas, particularly where the primary road network is sparse and there is limited scope for rerouting and diversion. Rainfall triggers the majority of landslides in the U.K. and national level 24-hr forecasts exist (for emergency response agencies), but there is uncertainty surrounding what combination(s) of duration and intensity trigger slope failures on a site specific level and why similar events do not always lead to the same event/no-event outcome. These knowledge gaps are critical where decisions must actively be made to warn users of (or close) linear infrastructure such as roads and rail in order to saves lives and costs. This lack of specificity, combined with the high costs of traditionally instrumenting known 'at risk' locations, hinders effective decision-making for key authorities and their partners. As a result many essential components of the environment are not monitored in advance, or on a wide-scale / high-resolution (spatial and temporal) basis. LIMIT will make use of and develop the next generation of low-cost and low-power integrated network (and networks of networks) sensors combined with edge processing and multi-threshold trigger based streaming of key data in near real-time to allow decisions underpinned by advanced theories of failure mechanics. The result is low cost, wide coverage provision of data that analyses the state of the environment and forecasts future behaviour at higher spatial and temporal resolutions than previously possible, integrated into a seamless 'data chain' from site to decision-makers. Data and key derivations based on fundamental process science are automatically ingested/shared into a newly constructed digital environment via an intelligent hierarchical platform. The outputs are fit for national data sets and modelling; policy makers deciding on sensor networks for monitoring evolving risk due to long-term environmental changes; operational decision-makers tasked with real-time management of acute threats to life; right though to data provision and two-way engagement with the individuals at risk. Innovative low-cost, in situ near real-time data streaming/processing sensors resiliently linked to an integrated portal with automated reporting offers a viable and transformative solution to end-user challenges. The LIMIT feasibility study will generate new field validated intelligent monitoring informatics, underpinned by advanced theories of failure mechanics, to provide critical data on the increasing likelihood and then the occurrence of slope failures in real-time.

3. Landslides onto and into glaciers (EPSRC IAA)

Slope processes play a significant role in sediment delivery to ice; a role of increasing importance as landscapes transition between glacierised and ice-free configurations. Landslide magnitude-frequency (m-f) which dictates the erosion of land exposed above ice surfaces (landslides, not glaciers, reduce peak height above ice) and the resultant sediment flux through the glacier-route-way is poorly quantified, particularly when the debris is entrained and transported en- and sub-glacially and re-emerges (altered or unaltered) in the ablation zones. Crucially, we have been unable to elucidate climate change-driven perturbations in m-f due to the sparsity and incompleteness of existing datasets and the absence of a thorough analysis of the suite of relevant environmental drivers. Estimates of the flux from landslides onto ice range from just a few percent to 60% of total glacial sediment flux.

We hypothesise that landslides in the Arctic and Antarctic deliver significant quantities of sediment including bioavailable iron (BioFe), silica, and nitrogen to the Oceans.

Professor Stuart Dunning

Professor of Applied Geomorphology

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