www hoddereducation co ukgeographyreview Coastal systems feedback mechanisms

Introduction This presentation supports the article by Catherine Pennington, et al. in GEOGRAPHY REVIEW Vol. 33, No. 4, pages 2– 6: ‘Measuring coastal retreat: a case study from Holderness’. The article describes the monitoring of cliff landslides on the Holderness coast and explains how the data obtained not only clarify the processes at work but can contribute to coastal management policy. Hodder & Stoughton © 2020

Features of a coastal system Coastal landscapes act as natural open systems with inputs,

Stores and flows in a coastal system Within any coastal area (or littoral zone)

Feedback mechanisms operate in coastal areas. There are two types of feedback mechanisms — positive and negative. An example of positive feedback in a coastal setting • the construction of a sea wall limits cliff erosion • this restricts the release of sediment into the system • this sediment might otherwise have been re-deposited, helping protect the coastline, and so without it, erosional processes increase on the coastal landscape • this erosion often takes place at another location, away from the original sea wall Hodder & Stoughton © 2020

An example of negative feedback in a coastal setting Hodder & Stoughton © 2020

Integrated coastal zone management (ICZM) ICZM requires: • that an entire littoral (coastal) zone is managed, not just the narrow zone where waves cause erosion, flooding or deposition, but also including all ecosystems and human activity in the zone • recognition of the importance of the littoral zone to people’s livelihoods as large numbers of people live and work at the coast • recognition that management of a littoral zone must be sustainable — economic development should improve the quality of life of people and this needs to be environmentally appropriate and equitable In the UK, shoreline management plans (SMPs) implement ICZM. Hodder & Stoughton © 2020

Shoreline management plans (SMPs) SMPs: • were introduced in 1995, with 22 identified in England Wales • do not exist in Scotland Northern Ireland, where the devolved governments and local authorities are jointly responsible for coastal protection • involve all stakeholders in making decisions about how coastal erosion and coastal flood risk should be managed • aim to balance economic, social and environmental needs and pressures at the coast • reduce risks to people and to the developed, historic and natural environment in a sustainable way • predict, so far as it is possible, the way in which a coastline will be shaped in the future (defined as 100 years). Hodder & Stoughton © 2020

SMPs in England Wales Hodder & Stoughton © 2020

Coastal management strategies (1) Four coastal management strategies (or policies) are often considered within the work of SMPs: • Hold the line • Advance the line • Managed retreat • No active intervention Hodder & Stoughton © 2020

Coastal management strategies (2) Making decisions about which strategy to apply in a particular location depends on: • the economic value of the land that could be protected • the cultural and ecological value of land, e. g. historic sites and areas of unusual biodiversity • the technical feasibility of the engineering required • the attitudes of, and pressure from, local communities Cost–benefit analysis is often used to help decide if defending a coastline from erosion and/or flooding is economically justifiable. Hodder & Stoughton © 2020

This resource is part of GEOGRAPHY REVIEW, a magazine written for A-level students written by subject experts. To subscribe to the full magazine go to: http: //www. hoddereducation. co. uk/geographyreview Hodder & Stoughton © 2020