Climate Change and the Implications for the Management of Coastal Landslides. James Houghton Senior Geotechnical Engineer Isle of Wight Council

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1 Climate Change and the Implications for the Management of Coastal Landslides James Houghton Senior Geotechnical Engineer Isle of Wight Council

2 Outline Background to landsliding on the Isle of Wight Current management strategies Specific projects aimed at reducing landslide risk

3 The Isle of Wight Coastline -Complex and Varied

4 The Undercliff

5 The Undercliff 12km 500m

6 Simplified Ventnor Landslide Model

7 Landslip at Bonchurch

8 Loss of Road at Niton

9 GIS Map Data, Ventnor Undercliff Ordnance Survey Base map Aerial photograph

10 Landslide Susceptibility in the Undercliff

11 Mean Monthly Effective Rainfall Change Scenarios at Ventnor From Halcrow, 2001

12 IWCCE Key Responsibilities Shoreline Management & Coast Protection Coastal, landslide and cliff monitoring and management Ground stability engineering Planning liaison over coastal, geotechnical and environmental issues Harbour management Dissemination of information and public relations through the Isle of Wight Coastal Visitors Centre

13 Isle of Wight Undercliff Landslide Management Strategy Undercliff Landslide Management Strategy (since 1992) Management Committee Planning control Building control Engineering measures Monitoring Planning guidance map Codes of good practice Coastal protection Forecast Drainage Early warning Loss mitigation

14 Isle of Wight Undercliff Landslide Management Strategy Action 1) Engineering measures (coastal protection works and drainage etc.) 2) Public education and information 3) The control of water in the ground 4) Avoidance of seriously affected areas 5) Further monitoring and research Example Construction of the Castlehaven coastal protection and land drainage scheme Opening of Coastal Visitors Centre in 1998 Advice to homeowners leaflets (periodically updated & reissued) E.g. The Graben, Newport Road, Upper Ventnor Ongoing ground movement monitoring, European funded projects, etc.

15 1) Engineering Measures Castlehaven

16 2) Public education & information The Coastal Visitors Centre, Ventnor The Coastal Centre is open to the public daily providing displays and information about the coastline of the Isle of Wight, including geology, environment, archaeology, coastal defences and landslides. The Centre also runs a varied programme of coastal based education.

17 3) Control of water in the ground: Advice to homeowners (New leaflet issued October 2004)

18 4) Avoidance of seriously affected areas The Graben, Newport Road, Upper Ventnor

19 5) Geotechnical Monitoring

20 The Monitoring Network Consists of approximately 100 sensors. Network constantly being expanded. Includes inclinometers, tiltmeters, piezometers, extensometers and settlement cells, as well as numerous telltales and other low-tech monitoring points. Readings taken at a variety of periods ranging from once a month to every three minutes.

21 Coastal Defence Policy IW Shoreline Management Plan 5 Yearly Review 100 Year Timeframe Isle of Wight North East Coastal Defence Strategy Study Sandown Bay and Undercliff Coastal Defence Strategy Study West Wight Coastal Defence Strategy Study Implementation Plan

22 Landslide Management Strategies Applicable to Climate Change (from Lee and Jones, 2004) The use of no regret or low regret options Adaptive management Delaying action Delay and buy time Changing the land use / site abandonment Contingency planning Making allowance for climate change in engineering schemes

23 Completed Revetment

24 Siphon Drain Solution: Layout Compressor Chamber Siphon drain Line A Siphon drain Line B Siphon drain Line C Electropneumatic drain - Line D Siphon drain Line E Siphon drain Line F Siphon drain Line G Siphon drain Line H DRAINAGE CONNECTIONS Outfall at Castlehaven Headland

25 Local & Regional: Standing Conference on Problems Associated with the Coastline (SCOPAC) The Solent Forum Isle of Wight Estuary Partnerships Schemes of Management for European Marine Sites South-East Climate Change Partnership National: Local Government Association Coastal Special Interest Group (LGASIG) Chairmen of the Coastal Groups of England and Wales Technical Advisory Group (TAG) Trans-National: Networks & Groups Arc Manche Conference of Peripheral Maritime Regions of Europe (CPMR) and the Islands Commission of CPMR World Landslide Networks e.g. United Nations International Strategy for Disaster Reduction (UN ISDR)

26 Coastal Change, Climate and Instability ( ) A Life Environment Success Story PROTECT PRediction Of The Erosion of Cliffed Terrains ( ) Response Responding to the Risks from Climate Change ( ) Eurosion ( ) EcoEnhance ( )

27 RESPONSE Responding to the risks from climate change supported by the European Commission's LIFE Environment Programme Developing sustainable strategies for the management of natural hazards in coastal areas taking account of the impacts of climate change.

28 (3 years) 5 Coastal Study Areas 9 Project Partners