The document provides an overview of a presentation on fluvial geomorphology given by Dr. David Hetherington. It includes details about his background and research interests in fluvial geomorphology. It also summarizes Ove Arup and Partners, the international engineering firm Dr. Hetherington works for, and discusses key concepts in fluvial geomorphology like catchment processes and small scale river features.

1. Fluvial Geomorphology –
From Theory to Practice
Dr David Hetherington
Ove Arup and Partners, Newcastle upon Tyne, UK.
Friday 4th June 2010, Sustainable Cities Forum
Universidad Javeriana Bogota Colombia
Javeriana, Bogota,

2. Personal Profile – David Hetherington
• BSc Geography
• MSc Catchment Dynamics and Management
• PhD Remote Sensing and Fluvial Geomorphology
• Have worked in Fluvial Geomorphology for 10 years.
• Employed for Over Arup and Partners (“ARUP”) for
5 years.
y
• My work relates to River Restoration,
Geomorphological Assessment, Flood Risk
Management and Geomatics.
• I operate the Arup “Geomorphology” and “Remote
Sensing” Communities (appx 80 staff).
S i ”C iti ( t ff)

3. Research Profile
• Geomorphological Evolution
• U of T
Use f Terrestrial LiDAR (Li ht Detection and
ti l (Light D t ti d
Ranging) in Rivers
• Use of Terrestrial LiDAR in Engineering
• Fish Habitat
• Hydromorphology and Hydraulics
• The use of Urban Models for Flood Risk
Management
M t
• Fluvial Geomorphology and River Restoration

4. Ove Arup and Partners (“ARUP”)
• An international multi disciplinary
consultancy firm of engineers,
scientists and designers (>10,000 staff)
i ti t dd i ( 10 000 t ff)
• Founded in 1946 by Ove Arup
Sydney Opera House was an
early project.
• Ove was an engineer and philosopher (he died in 1988)
• Recent large projects including much of the Beijing
Olympics.
• Independent and staff owned (trust).
• Please visit www arup com
www.arup.com

5. The Key Speech
• Ove Arup made the key speech in 1970 to remind Arup
staff of how they should operate: key points…
points
• Work should be interesting and rewarding and be of
the best quality p
q y possible
• All work should have a humanitarian attitude
• Work should be honourable with a social conscience
• Money is not the main aim
• We should be a force of good, and help to shape a
better world….

7. 520
65
105
35
130
GLOBAL WATER SKILLS NETWORK
March 2009

8. Fluvial Geomorphology – What is it?
• A river is something of unimaginable wonder . . .

9. Fluvial Geomorphology – What is it?
• An understanding of river behaviour . . . .

10. Fluvial Geomorphology – What is it?
• A complex earth science using elements of
Hydraulics, Geology and Physics.
• “the study of sediment sources, fluxes and storage
within the river catchment and channel over short,
medium and longer timescales and of the resultant
channel and floodplain morphology” (Newson and
Sear 1993).
• The study of river form-process interactions and
feedbacks over many scales, from the single grain
up to the entire catchment
catchment.
• In Short: An well-qualified Fluvial Geomorphologist
understands how rivers behave, and can use this
,
knowledge to manage them appropriately . . .

11. Fluvial Geomorphology – Catchment Processes

12. Fluvial Geomorphology
– Catchment Controls
• Catchment nature
ultimately determines
habitat in natural
conditions
• Diract (
(local) and
)
Indirect (Catchment)
Anthropogenic changes
p g g
disrupt natural reactions
and responses
• Taken from Brierley and
Fryirs, 2007 – River
styles

13. Fluvial Geomorphology – Small Scale

14. Fluvial Geomorphology – Why do we need it?
(1)
• Rivers are the arteries of the landscape . . .
• Freshwater rivers are valuable and only cover
around 0.0001% of the Earth’s Surface. (0.0002% of
(
total volume of water) – NASA estimate
• Natural rivers are physically diverse over short
distances supporting unique assemblages
• Healthy river systems typically offer better fish
stocks, and better quality water to local
communities.

15. Fluvial Geomorphology – Why do we need it?
(2)
• Healthy meandering systems can help to maintain
y g y p
aggracultural water table levels.
• Upland meandering systems can provide upstream flood
storage (reducing flood risk downstream).
• Designing with natural geomorphological processes is
key
k if new engineering schemes are to be sustainable
i i h b i bl
and environmentally sensitive.
• Rivers are important community features and
boundaries

16. Fluvial Geomorphology – Why do we need it?
(3)
• Rivers are hydraulically and morphologically dynamic in
time, making then unique spaces.
• Support varied and sometimes rare flora and fauna
pp
(which has evolved to natural systems)
• Damage needs repair
• As with most habitats, the quality of the physical space
plays a major role in promoting healthy ecology
•N t
Natural and restored rivers look better and make people
l d t d i l k b tt d k l
happy!

17. Ecology - Fisheries

18. Fluvial Geomorphology and good quality
rivers
e s
What is considered as
being a good quality Geomorphology
gy
i ?
river? and
Hydromorphology
1) Suitable physical
habitat for native
species
2) Suitable water quality
to support sensitive
native species
Ecology Water quality
3) Availibility /
introduction of native
species

19. Fluvial Geomorphology and good quality
rivers
e s
What is considered as
being a good quality Geomorphology
gy
i ?
river? and
Hydromorphology
1) Suitable physical
habitat for native
species
2) Suitable water quality
to support sensitive
native species
Ecology Water quality
3) Availability /
introduction of native
species

20. Fluvial Geomorphology in the UK

21. Fluvial Geomorphology in the UK

22. Fluvial Geomorphology in the UK

23. Fluvial Geomorphology in the UK

24. Fluvial Geomorphologists
• It is a specialist subject that usually requires
outside contractors to supply the necessary levels
of expertise. From the outset it is important to make
clear that like any science, a broad understanding of
principles only gets you so far, and a little
far
knowledge can be a very dangerous thing.
Source: (DEFRA) R&D TECHNICAL REPORT FD1914
(DEFRA), FD1914,
Applied Fluvial Geomorphology.
• It is a profession, and a job of responsibility

25. Expertise Levels in the UK
DEFRA R&D TECHNICAL REPORT FD1914

26. Legislation and Authorities
The Water Framework Directive - Legislation
•To protect, and where necessary, restore the structure and function of
the aquatic ecosystem
•An obligation to return our rivers to their natural hydromorphological
state
•The aim of achieving “good ecological status”
The UK Environment Agency
•The UK statutory body responsible for caring for the environment
•Powers to prosecute in response to damage to river systems
•Promote restoration and habitat creation wherever possible
•Have published recent guidance on Ri
H bli h d t id River W k
Works

27. The Department for Environment, Food, and
Rural Affairs (DEFRA)
• Government Department
• Conduct research of a national interest
• Produce Guidance
• With the Environment Agency - C Commissioned a
“Guidebook of Applied Fluvial Geomorphology”
(
(R&D Technical Report FD1914) in 2003
p )
• By D Sear, M Newson and C Thorne.
• Freely Available on line.
line
• Sets national standards and raised the profile and
requirement for Fluvial Geomorphology.

28. The River Restoration Centre (RRC)
• “A national information and advisory centre on all
aspects of river restoration and enhancement, and
sustainable river management
management”
• The RRC and an Non-Profit organisation based in
Nottingham, UK.
• A hub for best-practice and knowledge sharing
• Keep databases of projects and outcomes
• Offer consultancy services (checking and review)
• Work with rivers trusts and local fisheries
• Offer promotion and training on River Restoration.

29. Drivers for Geomorphological Studies and
work
• Ecology
• Fishing
• Social (Recreation / Community)
• Landscape Improvement
• Stability (Land Erosion)
• Understanding of impacts of river change
• Engineering (allowing for natural processes)
• Flood Risk Management
• Sediment Management
g

30. From Assessment to Enhancement . . .
1) Asses – Measure/Map/Log evidence of the system
2) Understand – Analyse the Data
3) Identify problems – Reveal key information of
quality
4) Prioritise – Use information to plan rehabilitation
5) Restore – Propose sensible, sensitive and
sustainable solutions that consider many environmental
and social factors.

31. Geomorphological Assessment
• 3 broad levels of approaching investigation
and Assessment
Small - Immediate
• Site Specific Local scale
• E g geomorphological impacts of weir removal or
E.g.
channelisation
• Reach Scale
• Restoration plans, rivers with special status,
sediment management plans, water level
management p
g plans, fisheries improvements.
, p
• Catchment scale
• Catchment Audits and Management Plans
Large – Long Term

32. Desk Study Information
• Old photographs
• Ai b
Airborne photographs
h t h
• Old Mapping
• Anecdotal evidence
• Flow Records
• Topographic information
• Agency / Government records
g y
• Geological information

33. Empirical vs Rational Approaches
• Empirical understanding based upon spatial
measurements (quantitative)
• Requires skills in selecting the correct measurement
techniques, methodologies and Processing and analytical
methods.
• Rational understanding based upon experience-
based observations (qualitative)
• Requires “hands-on” experience in various river systems to
q p y
understand how they operate under different conditions, and
react to catchment changes.
• Most studies use a combination of Empirical and
Rational Geomorphological work.

34. Empirical Tools – Field mapping
• Locating features onto maps or direct into GIS
• Handheld GIS has built in GPS technology (How
long until we can install GIS on our I-phones?)

35. Empirical Tools – Surveying and Terrestrial LiDAR

36. Rational Tools - Experience
• Field proforma allowing descriptions and mapping
of:
• Types of erosion and deposition
• Types of sediment Bar Features
• Severity of Erosion
• Severity of Deposition
• Evidence of active and dormant processes
• Evidence of Morphological features (Riffles, pools etc)
• Hydromorphological units (runs, cascades, riffles, ponded
flow etc)
)
• Anthropogenic influences (farming, dumping, livestock
etc)

37. Rational Tools - Proforma

38. Geomorphological Patchiness and Diversity
• Patchiness is an expression of the number of
different key geomorphological features
identified within an individual reach.
• Di
Diversity i a product of patchiness - th t t l
it is d t f t hi the total
number of all features within a reach, multiplied
by the number of different feature types present
within the reach (i.e. patchiness). It is thus a
measure of the frequency at which key features
q y y
occur along a reach.

39. Assessment of Geomorphological quality
• Scales and criteria can be manipulated to suit the
p
catchment, and to reflect absence or presence of
key project features.

40. GIS analysis

41. Restoration options

42. Restoration projects – in channel options
Back water channel Log v weirs
Flow deflectors/ D’s
Ds Flow deflectors/groynes

43. Catchment Scale – Geomorphological mapping
Geomorphological Standard
Diversity V.low
low
Mod
High
V.high
V hi h

44. Catchment Scale – Ecological mapping
V.low
low
Mod
High
V.high
V hi h
Standard diversity for salmonids,
lampreys and bullheads (EA technical
manual - Hendry & Cragg-Hine, 1997)

45. Geomorphological – Ecological links
Geo Eco Com
40.00 R-Sq = 7.8%; P = 0.037
versity
30.00
Ecolog Standard Div
20.00
gy
10.00
0.00
0.00
0 00 5.00
5 00 10.00
10 00 15.00
15 00 20.00
20 00 25.00
25 00 30.00
30 00 35.00
35 00 40.00
40 00
Geomorphology Standard Diversity

46. Geomorphological – Ecological links
Geo Eco Com
R-Sq = 7.8%; P = 0.037
Target for restoration
Good Quality y
Judgement required

47. Project Example – River Mease
• A Site Specific – Geomorphological Impact
assessment of removing a weir

48. Project Example – River Mease

49. River Mease - Considerations
• Important habitat for Bullhead
• Important habitat for Spined Loach
• Local regime will change
• Local sediment transport potential will change
• Local hydraulic diversity will change
• Upstream impacts?
• Downstream Impacts?
• Flood Risk?
• Stability

50. River Mease – Existing Conditions

51. River Mease – Restoration/mitigation Proposals

52. River Mease – Anticipated hydraulic habitat

53. River Mease - Outcomes
• Impact assessment reveals opportunities!
• Habitat for key species promoted in new layout
y p p y
• Opportunities found to relocate vegetation
• Improved local floodplain connectivity
• Upstream hydraulic diversity improved as
backwaters are removed
• Improved aesthetics
• Reduced livestock access
• Land-owners appeased

54. Project Example – Beam Parklands
• A reach based assessment to inform landscape
improvement for community use

55. Beam Parklands – Landscape Vision

56. Beam Parklands - Considerations
• No access for fish (downstream sluice)
• Urban – high population area, community park
• Very Low Morphological or Hydraulic Diversity
• Heavily modified system
• Currently inaccessible
• Very low gradient
• Invasive plants
• Polluted site
• No key species present

57. Beam Parklands – Restoration Plan

58. Beam Parklands - Outcomes
• Accessible park landscape promoting community
involvement and natural play
• Two restored rivers with dramatically improved
geomorphological,
geomorphological hydraulic and ecological
diversity.
• Pool riffle sequence mimicking natural conditions
• Wetland areas
• Improved flood storage

59. Hydromorphology and Hydraulic Diversity
• Definition:
“The physical characteristics of the shape, the
boundaries and the content of a water body” Water
Framework Directive Definition
• A key part of this “content” is spatio-temporal
k t f thi “ t t” i ti t l
hydraulic diversity.
• Fish plant and invertebrate species undertake
Fish,
different parts of their life cycles and daily routines
in different hydraulic units (Biotopes) – Diversity is
key.
• It is possible to map these flow unit habitats
(Biotopes) visually, b t this comes with many
(Bi t ) i ll but thi ith
problems.

60. Biotopes (hydraulic habitats)
Biotope Types

62. Mapping Hydraliuc Diversity using terrestrial lidar
•The local standard deviation of the data were computed using a 0 2 m radius
0.2
moving window
•Data were gridded at 0.04 m so as to capture the smallest biotope unit seen
at the study sites
•Local standard deviation values at each of the measured biotope locations
were then extracted from the grids using the residual function in SURFER™
•Local standard deviation values interrogated at each known biotope location
•Statistical properties of each biotope determined
Statistical

63. Biotope signals

64. Results: Typology validation
frequency biotope successfully
Unit descriptor classified frequency amalgamated biotope successfully classified
Run 0.00 0.90
Glide
Glid 0.14
0 14 0.75
0 75
Chute 0.20 0.59
Rapid 0.38 1.00
Riffle 0.25 0.55
Deadwater
D d t 0.71
0 71 0.71
0 71
Pool 1.00 1.00

65. Research outcomes
• Different features offer similar surface structure
(suggesting similar hydraulics).
• Current system for classifying hydraulic units are
over-complex.
• Rivers present a continuum of hydraulics, rather
than defined units (fuzzy boundaries in time and
space).
• Potential for analysing exiting LiDAR data on larger
river systems.
y
• Methods limited to local and reach scales of
investigation (quantifying betterment).

66. Terrestrial lidar and design

67. Conclusions – Fluvial Geomorphology
• Diagnosing the problems and causes is key to
management.
• The scale that processes are operating at should
determine the scale of the study, and the response.
• S ll scale processes/problems = Local studies
Small l / bl L l t di
• Catchment scale processes/problems = Large
studies
• Consideration of this early on makes schemes
sustainable,
sustainable and adds value (in many ways)
ways).
• It is a serious and complex subject and expertise is
required.
q

68. Conclusions – River Restoration
• We need to learn from, and correct historical
mistakes.
• M h existing guidance and project experience.
Much i ti id d j t i
• Should be based on a sound understanding of the
River System
System.
• Needs to be focused on the drivers.
• What conditions to key species require?
• Provides multiple direct benefits (and residual
benefits e.g. water quality).
b fit t lit )
• Often a far more cost effective solution than hard
engineering.
engineering

69. River Restoration: Costs
• Hard to generalise in terms of economics (projects
so diverse!)
• S ft V H d (S ft approximately 25-50% cheaper at
Soft Vs Hard (Soft i t l 25 50% h t
initial outlay)
• Cost per m <50% for soft
• Engineers vs Bio-engineers (bioengineering groups
small with low overheads - 50% in some cases)
• Soft then requires monitoring, and maintenance
• But has a longer design life because of this
g g
• Restoration should be part of other schemes.
• Additional cost – but great additional benefit
• Cost does not reflect “value”

70. River Restoration: Limitations
• A river can never be fully “restored” back to its
original state.
i i l t t
• Sometimes difficult to design for extreme flood
events.
events
• Sometimes restoration has to be done within
constraints
• Huge potential benefits make the limitations worth
working with

71. Acknowledgements
• The project organisers in Bogota!
• Arup for supporting my involvement
• The below Arup people for contributing and/ helping
in various ways towards my attendance and
y y
presentation at this forum:
Patrick Kuhn, Amit Dutta, Dr Sally German, David Wilkes, Prof
Mark Fletcher Daniel Newton Daniel House Jane Saul
Fletcher, Newton, House, Saul.
• Dr David Bradley – APEM aquatic scientists
• Research Colleagues
• Dr George Heritage – Salford University, UK
• Dr David Milan – University of Gloucestershire, UK

72. Questions?
david.hetherington@arup.com
(Please stay in touch!)
Useful Additional Background Information . .
• DEFRA: www.defra.gov.uk (search for “fluvial g
g ( geomorphology”)
p gy )
• EA fluvial design guide: http://evidence.environment-
agency.gov.uk/FCERM/en/FluvialDesignGuide.aspx
• River Restoration Centre: www.therrc.co.uk