Jurassic Coast Pathfinder Project: Coastal Change Visualisations
Jurassic Coast Pathfinder Project:
Coastal Change Visualisations
July 2011
Contents
1. Introduction 2 2. Methodology 2 3. Technical notes 3 4. Evaluation and public response 3 5. The visualisations: 5.1 Swanage 5 5.2 Ringstead 11 5.3 Preston Beach Road, Weymouth 17 5.4 Seatown 18 5.5 Charmouth 23 5.6 Pennington Point, Sidmouth 26
1 Jurassic Coast Pathfinder Project: Coastal Change Visualisations
1. Introduction
A primary aim of the Jurassic Coast Pathfinder Project was to help communities better understand coastal change and how it could impact on the coast in their local area. One of the means by which the project sought to address this aim was through the production and presentation of computer generated visualisations to illustrate how the coast at each of the six project case study communities might evolve over the next 100 years.
2. Methodology
The project team appointed Halcrow Group Ltd to produce the coastal change visualisations. For each of the six case study sites Autodesk LandXplorer 2011 was used to produce a digital terrain base model using LiDAR data (light detection and radar) and aerial photography from the Channel Coast and South West Coastal Observatories, part of the DEFRA funded National Strategic Monitoring Programme. These base models showed the coast as it appeared in 2010.
Erosion risk lines for 2050 and 2100 derived from the draft National Coastal Erosion Risk Mapping published in the South Devon and Dorset Shoreline Management Plan and Poole and Christchurch Bays Shoreline Management Plan were then used to manipulate the base models to show how the coast might evolve in future.
The derived erosion lines were subject to expert peer review and are conservative compared to the 'worst case' risk identified in the risk mapping as risk mapping is just that; identifying risk rather than predicting exactly where the coast may be in any given time period. An example of how difficult this is to achieve can be found at Charmouth, where part of the cliff has recently retreated due to a landslide beyond the 2100 risk line. Parts of the newly formed cliff are now likely to be stable and will form the cliff edge for at least the next 100 years.
The visualisations produced were used to support a series of scenario planning workshops held in each case study community during autumn 2010 - spring 2011. During these workshops, the visualisations were presented to participants as ‘fly through’ video clips and still images. Still images were incorporated into displays of photographs showing historical coastal change in each community.
Fig 1. Visualisations of Charmouth and Seatown on display at a Jurassic Coast Pathfinder public exhibition
2 Jurassic Coast Pathfinder Project: Coastal Change Visualisations
Following the completion of the pathfinder project scenario planning exercise, final versions of the visualisations were presented to the general public at a series of exhibitions held in Swanage, Weymouth, Charmouth and Sidmouth during June and July 2011.
The exhibitions incorporated both the still images and ‘fly through’ animations and attendees were also able to navigate the digital terrain models themselves on a computer screen enabling community members to focus on areas of particular interest to them.
3. Technical notes
The process of altering digital terrain models requires a range of technical skills. There is a need for expertise in altering the topography of the digital terrain models and in altering the aerial photography to match the underlying terrain.
Altering the aerial photography requires relatively advanced photo editing skills (e.g. using Adobe Photoshop) and an understanding of how the cliffs fail and change. Major change presents a unique challenge because there may not be sufficient existing textures in the photography to copy or clone to illustrate that change. Understanding is also required of the nature of coastal erosion and cliff failure. The Jurassic Coast Pathfinder communities are characterised by complex cliffs with changing geology and cliff recession is not uniform. Landslides tend to fail in curved or arcuate forms and sometimes clues to likely future failure can be seen within existing aerial photography. Faults and dipping strata produce similar detail which is necessary to incorporate in order to realistically reflect how the coast may evolve over time.
4. Evaluation and public response
Feedback from participants at the Pathfinder Project workshops and public exhibitions indicated that the visualisations are a powerful tool for helping people understand how coastal change could impact on their community. Workshop participants noted that the visualisations aided them in identifying both the implications and inevitability of coastal change and in doing so helped them appreciate the need to plan for adaptation.
Attendees at the Pathfinder public exhibitions were asked to complete an evaluation form which included the question ‘What did you like most about the exhibition?’ Responses to this question included:
• ‘the timeline display and future predictions’ (Sidmouth) • ‘visualisations of erosion at Pennington Point’ (Sidmouth) • ‘photos and simulations’ (Charmouth) • ‘Photos of the future’ (Charmouth) • ‘Photos in time and images of the future’ (Swanage)
3 Jurassic Coast Pathfinder Project: Coastal Change Visualisations
When discussing the value of these exhibitions with the attendees there was an overwhelming response about the value of the visualisations in helping them understand possible future change.
5. The Visualisations
The following section provides a series of still images taken from the visualisations for each of the six Pathfinder Project case study sites. Due to the variation in scale of the six case study sites, the number of images detailed for each location varies. Those included have been chosen to demonstrate the capacity of the digital terrain models for illustrating coastal change from different aspects and at different scales including showing large urban areas and focussing on individual coastal features.
PLEASE NOTE: These visualisations attempt to show how the coast may change in the future based on Shoreline Management Plan policy and National Coastal Erosion risk mapping. As a result, the predictions illustrated should only be regarded as indicative of how the coast may evolve in the future. Similarly, the time frames are also indicative; the change will come but it is not possible to predict exactly when.
The visualisations of Pennington Point, Sidmouth are based on the original draft Shoreline Management Plan 2 policy of No Active Intervention. However that has since changed to Managed Realignment and therefore this series of visualisations show a ‘worst case scenario’ if Managed Realignment were to not include further beach management schemes.
4 Jurassic Coast Pathfinder Project: Coastal Change Visualisations 5.1 North Swanage 2010
5 Jurassic Coast Pathfinder Project: Coastal Change Visualisations North Swanage 2050
6 Jurassic Coast Pathfinder Project: Coastal Change Visualisations North Swanage 2100
7 Jurassic Coast Pathfinder Project: Coastal Change Visualisations North Swanage 2010
8 Jurassic Coast Pathfinder Project: Coastal Change Visualisations North Swanage 2050
9 Jurassic Coast Pathfinder Project: Coastal Change Visualisations North Swanage 2100
10 Jurassic Coast Pathfinder Project: Coastal Change Visualisations 5.2 Ringstead 2010
11 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Ringstead 2050
12 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Ringstead 2100
13 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Ringstead 2010
14 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Ringstead 2050
15 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Ringstead 2100
16 Jurassic Coast Pathfinder Project: Coastal Change Visualisations
5.3 Preston Beach Road 2010
17 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Preston Beach Road 2050
18 Jurassic Coast Pathfinder Project: Coastal Change Visualisations
Preston Beach Road 2100
19 Jurassic Coast Pathfinder Project: Coastal Change Visualisations 5.4 Seatown 2010
20 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Seatown 2050
21 Jurassic Coast Pathfinder Project: Coastal Change Visualisations
Seatown 2100
22 Jurassic Coast Pathfinder Project: Coastal Change Visualisations 5.5 Charmouth 2010
23 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Charmouth 2050
24 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Charmouth 2100
25 Jurassic Coast Pathfinder Project: Coastal Change Visualisations 5.6 Pennington Point, Sidmouth 2010
26 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Pennington Point, Sidmouth 2050
27 Jurassic Coast Pathfinder Project: Coastal Change Visualisations Pennington Point Sidmouth 2100
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