Fluvial geomorphology and flood risk management

Freshwater flooding is expected to become increasingly common as climate change intensifies the hydrological cycle, affecting the lives millions of people living in flood-prone areas across the world.

However, such increases in flood magnitude and frequency are not purely climate-related. Widespread human disturbance alters fluvial networks and the capacity of river channels to contain flood flows.

In the first part of this seminar, Dr Louise Slater (Loughborough University), will demonstrate that flood risk can only be fully understood by taking both hydrologic and geomorphic changes into account. She will present research quantifying the influence of changing river channel capacity on flood hazards in hundreds of rivers across the USA and UK, drawing on historic date.

Focussing on a few key locations, she will show that these changes in river channels can be caused by a variety of management decisions and land use changes upstream.

These analyses reveal that geomorphic changes are widespread, can occur rapidly, and have a measurable effect on flood hazards.

Dr Slater’s work on the channel capacity part of the flood hazard equation strongly informed the realisation that the Environment Agency’s river discharge measurements could be extremely valuable in developing a more holistic view of the causes and impacts of flooding.

A single river gauging exercise can now yield up to 50,000 individual 3-dimensional measurements of water velocity and direction and several thousand bathymetry readings. The addition in recent years of high precision GPS to the monitoring instrumentation further increases the value of these datasets, by accurately geo-referencing every data point. Thus the humble river gauging becomes a very powerful survey of channel morphology and hydraulic conditions.

In the second part of this seminar, Nick Everard, the Environment Agency’s National Lead for Hydrometry and Telemetry, will tell the story of how technology has transformed river flow measurement methods in the UK, looking to a future where innovative new methods enable measurement of even the most extreme flood peaks, and where smartphones and low cost cameras become valuable flood monitoring equipment.

About the speakers

Dr Louise Slater
Louise is a Lecturer in Physical geography at Loughborough University. Her research focuses on understanding and predicting changes in floods and fluvial systems in the context of contemporary shifts in climate, agricultural practices and urbanisation.

Using statistical and computational tools, Louise’s research aims to disentangle the different drivers of flooding and fluvial change across a variety of climates and land use types. She uses changes in land cover and climate to develop probabilistic streamflow forecasts over a range of timescales, to assess how fluvial systems may change over time.

Louise has a keen interest in data science and in developing new, interdisciplinary methods for understanding and projecting fluvial and hydro-climatic chan

Nick Everard

Nick Everard leads the Environment Agency’s programme on river discharge measurement technologies. With 30 years of experience, Nick has played a major role in transforming the quality, efficiency and safety of discharge measurements at the EA through the adoption of ADCP acoustic monitoring technologies. Now, the challenge is developing new measurement solutions capable of meeting the dual challenges of greater extremes of high and low flows, and tighter funding streams.

Nick is a firm believer in the power of collaboration and has developed a global network of hydrometry researchers and practitioners, with over 220 members in around 20 countries.
This seminar in part of the Oxford Water Network’s ‘hydroclimatic extremes’ series and will be followed by refreshments at Christ Church.