© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 2.5How can human activity influence and activity influence and alter river and coastal alter river and coastal environments? environments? Part B

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge A bay in San Francisco, California, USA How do people make use of the coastal areas? Can you suggest how people make use of the coastal areas? Can the activities you mentioned be found in Hong Kong?

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge How do people make use of the coastal areas? In general, the following activities are found: Tourism and recreation Urban development Power generation Industrial activities

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge How do people alter the coast? AReclamation The development of commercial and residential buildings in West Kowloon (Credit: Liang Wing Hang Yanchap) Reclamation is carried out to obtain land for urban development. It changes the shape and form of the coastline. Reclamation has been carried out near old Star Ferry in Central for the construction of expressways

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge How do people alter the coast? BDredging A dredger (Credit: Liang Wing Hang Yanchap) When deposition is active at a harbour, dredging is carried out to ensure that the port can accommodate large ships. Dredging is also practised for obtaining materials for reclamation and construction.

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge Coastal erosion and deposition are continuing processes. They can shape the shoreline and this has profound impact on human activities. People need to manage the coast to ensure the continuance of human activities. Two approaches are often used. AHard approach (structural response) 1.Groynes 2.Breakwaters 3.Sea walls 4.Rock armour BSoft approach (non-structural response) 1.Beach nourishment 2.Mangrove planting 3.Coral reef growing 4.Vegetation planting 5.Relocation and land use zoning How do people manage the coast?

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 1Reclamation What are the consequences of coastal alterations? In Hong Kong, reclamation projects on both sides of Victoria Harbour narrow the harbour. It increases the speed of water currents and affects the safety of navigation. It may also bury the habitats of aquatic organisms and disturb aquatic ecosystems. The land at both sides of Victoria Harbour Reclaimed land

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 2Dredging What are the consequences of coastal alterations? Dredging shingle would expose the coast to erosion, e.g. the case of Hallsands village in the UK. Dredging may stir up sediment and pollutants from the seabed, which can disturb aquatic ecosystems. 1. Shingle beach before dredging of sand and shingle offshore Sea Sea level 2. Cliff eroded by sea after removal of shingle 3. Part of the village was destroyed 4. Present location of cliff Hallsands village (abandoned)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 3Pollution and the ecological balance What are the consequences of coastal alterations? Sewage and waste from homes, businesses, factories, hotels and other recreational facilities could upset marine ecosystems. Structural work may block sediment movement. It leads to changes in the natural habitat. Tourist facilities along a beach in Cancun, Mexico

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge What are the limitations of coastal management strategies? Groynes Longshore drift Groynes block longshore drift Beaches further along the coast may be more vulnerable to wave erosion Groynes in Dorset, UK (Credit: Rex Features)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge What are the limitations of coastal management strategies? Breakwaters Accumulation of sand behind the breakwater Breakwater Breakwaters protect the coast behind (Credit: Rex Features)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge What are the limitations of coastal management strategies? Sea walls and rock armours Expensive to build and maintain A sea wall Rock armour Expensive if rocks are imported Rocks must be large and heavy enough to remain stable Dangerous to young children (Credit: Tsui Chung Pong David)(Credit: Corbis)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge What are the limitations of coastal management strategies? Beach nourishment The beach of Repulse Bay Sediment of the beach may lose after a storm Regular maintenance is needed Costly (Credit: Getty Images)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge What are the limitations of coastal management strategies? Mangrove planting and coral reef growing Mangrove planting Careful protection is needed for young mangroves Coral reef growing Ensuring that the water is free from pollution

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge What are the limitations of coastal management strategies? Vegetation planting, relocation and land use zoning Vegetation planting Planting vegetation on cliffs or poor soil is difficult Relocation and land use zoning People with investments and properties at the coast are reluctant to move Costly compensation

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge Rivers and coasts are our valuable resources. We should manage them in a sustainable way. To set up a sustainable management strategy, we need to - examine the balance between four parties; - carry out cost-benefit analysis. SocietyEnvironment EconomyGovernment What should people do to face the continued challenges posed by the management of river and coastal environments?

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 5. Investigate the balance between four aspects in the management strategy 1. Define objectives 2. Consider the impact of human 3. Set indicators for use with environmental-based management 4. Design effective assessment methods 6. Implement management strategy 7. Evaluate outcome Let’s look at how the UK works out her shoreline management plans (SMPs)! Management strategy evaluation model

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 5. Investigate the balance between four aspects in the management strategy 1. Define objectives 2. Consider the impact of human 3. Set indicators for use with environmental-based management 4. Design effective assessment methods 6. Implement management strategy 7. Evaluate outcome Case study: Shoreline management plans (SMPs) in the UK 1. Define objectives The aims of SMPs: 1.Improve understanding of coastal processes; 2.Set up long-term planning of coastal defences and land use.

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 5. Investigate the balance between four aspects in the management strategy 1. Define objectives 2. Consider the impact of human 3. Set indicators for use with environmental-based management 4. Design effective assessment methods 6. Implement management strategy 7. Evaluate outcome Case study: Shoreline management plans (SMPs) in the UK -Assessing the risk to people and the natural environment; -Devising a sustainable management strategy with four policy options: Do nothing Hold the line Advance the line Retreat 3. Set indicators for use with environmental-based management

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 1. Define objectives 2. Consider the impact of human 3. Set indicators for use with environmental-based management 4. Design effective assessment methods 5. Investigate the balance between four aspects in the management strategy 6. Implement management strategy 7. Evaluate outcome Case study: Shoreline management plans (SMPs) in the UK 5. Investigate the balance between four aspects in the management strategy Case: SMP for Holderness coast -Rolston: 1.Tackle wave erosion 2.Major land use: agriculture 3.Low population -Bridlington: 1.Tackle wave erosion 2.Major land use: holiday resorts, nationally important place for seabirds

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge 5. Investigate the balance between four aspects in the management strategy 1. Define objectives 2. Consider the impact of human 3. Set indicators for use with environmental-based management 4. Design effective assessment methods 6. Implement management strategy 7. Evaluate outcome Case study: Shoreline management plans (SMPs) in the UK Case: SMP for Holderness coast -Rolston: Option: Do nothing -Bridlington: Option: Hold the line (Methods: Promenade, sea walls, groynes) 6. Implement management strategy

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge AThe ‘hard’ approach: Structural response 1Groynes Groynes are barriers built at right angle to the coastline to stabilize beach deposits. Longshore drift Groynes Longshore drift moves the sand deposits parallel to the shore. Groynes in Dorset, UK (Credit: Rex Features)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge AThe ‘hard’ approach: Structural response 2Breakwaters Breakwaters are long piers built offshore to reflect and dissipate the energy of incoming waves. The coastline is protected from erosion. breakwaters typhoon shelter The Aberdeen Typhoon Shelter (Credit: Lam Man Lok)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge AThe ‘hard’ approach: Structural response 3Sea walls Sea walls are built parallel to the shoreline to protect the coast by reflecting wave energy. The coastline is protected from wave erosion. Curved concrete sea wall Cliff Wave energy is reflected by the presence of the sea wall SeabedToe protectionSheet piling (Credit: Corbis)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge AThe ‘hard’ approach: Structural response 4Rock armour Rock armour is a barrier of large, irregular shaped rocks or concrete placed at the coastline. They protect the coastline from wave erosion. (Credit: Getty Images) Rock armour

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge High Island Reservoir, East Dam

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge BThe ‘soft’ approach: Non-structural response 1Beach nourishment Stabilizing the coastline by adding a large quantity of sand or shingle to the beach. Repulse Bay in Hong Kong is an example of beach nourishment. Repulse Bay is a famous tourist spot in Hong Kong (Credit: Getty Images)

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge BThe ‘soft’ approach: Non-structural response 2Mangrove planting Mangroves can protect the coast against erosion by strong waves and winds by binding the soil. Mangroves can bind the soil and thereby prevent coastal erosion

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge BThe ‘soft’ approach: Non-structural response 3Coral reef growing Coral can reduce the speed of waves approaching the coast and thereby protect beaches against coastal erosion. Coral reefs under the sea

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge BThe ‘soft’ approach: Non-structural response 4Vegetation planting Planting vegetation on cliffs can increase their stability and thereby stabilize the shore. Structures on a sea cliff

© Oxford University Press 2009 Quit Part 2 Managing river and coastal environments: A continuing challenge BThe ‘soft’ approach: Non-structural response 5Relocation and land use zoning Removing or relocating coastal properties to safe ground helps prevent loss of life and property. In the eroding coastal areas, only limited, or even no development, is allowed.