Rivers and Coastal Processes

River discharge (volume of water in a river at a specific time and place) can increase or decrease based on several factors. High precipitation, melting ice caps, steep gradients, and urbanisation all increase discharge. Meanwhile, low rainfall, dams, and vegetation can decrease it.

Hydrographs show how rivers respond to rainfall. They display the relationship between rainfall and discharge over time, with the lag time (delay between peak rainfall and peak discharge) affected by drainage basin size, vegetation cover, valley steepness, and soil type.

💡 The lag time on a hydrograph tells you how quickly a river responds to rainfall - shorter lag times often mean higher flood risks!

Coastal landforms develop differently depending on rock formations. Concordant coastlines have rock bands parallel to the wave front, creating similar erosion rates. Discordant coastlines have alternating hard and soft rock at right angles to the sea, forming distinctive headlands and bays. Sand dunes form when wind carries sand inland, with embryo dunes developing first before eventually becoming mature dunes, while dune slacks form where the water table is exposed.

Tundra Biome: Alaska Case Study

The Alaskan tundra has distinctive characteristics including a short warming period of 12°C for only 3-4 months each year. Plants and animals have fascinating adaptations for survival - plants grow close together with short stems and thorny features, while animals like polar bears have developed two layers of fur, high fat content, and large feet to spread their weight.

Alaska offers several economic opportunities including fishing (supporting 78,500 jobs), mining, tourism (generating $6 billion), and hydroelectric power which supplies half the region's energy. Indigenous tribes like the Inuit maintain traditional lifestyles, with special hunting rights for some communities.

⚠️ Climate change is causing permafrost to thaw in Alaska, creating thermokarst landscapes and releasing methane that further accelerates global warming!

The region faces significant challenges including environmental damage from gold mining, seasonal employment, poor infrastructure, and conflicts between conservation and development. The Arctic National Wildlife Refuge (ANWR) represents this tension, with ongoing debates about whether oil drilling should be permitted in this protected wilderness area.

Amazon Rainforest

The Amazon rainforest in Brazil features a humid climate, dense vegetation, and remarkable biodiversity. Plants have evolved special features like drip tips on waxy leaves to shed excess water, buttress roots for stability, and lianas (woody vines) for climbing. Animals use camouflage $like three-toed sloths$ or deterrents (poison dart frogs) to survive.

Deforestation continues for several reasons: commercial logging for profitable hardwood, mineral extraction, farming, road building, and population pressure. This creates a complex mix of impacts across different areas.

🌳 When a section of rainforest is cut down, it's not just trees we lose - it's an entire interconnected ecosystem that may have taken centuries to develop!

The social, economic and environmental impacts of deforestation are far-reaching. While providing jobs and economic growth, it threatens indigenous communities, reduces biodiversity, contributes to global warming, and causes soil erosion. Sustainable management approaches include ecotourism, debt reduction programs, protection laws, education initiatives, and selective logging practices that aim to balance human needs with conservation.

Earthquake Case Studies

The 2011 Christchurch earthquake in New Zealand (magnitude 6.3) occurred at a destructive and conservative plate boundary where the Pacific plate slid past the Australian plate. Primary effects included 185 deaths, 3,129 injuries, and damage to 100,000 buildings. Secondary effects included liquefaction making roads impassable and significant damage to water and sewerage systems. The response involved international rescue crews, temporary housing, and extensive infrastructure repairs.

The 2015 Kathmandu earthquake in Nepal (magnitude 7.9) was more devastating due to occurring in a less economically developed country. It happened when the Indian plate collided with the Eurasian plate at a destructive boundary, with a shallow focus of just 15km.

⚡ The shallow depth of the Nepal earthquake made it particularly destructive - the closer to the surface an earthquake occurs, the more intense the shaking at ground level!

Nepal's earthquake resulted in 9,000 deaths and left 3 million people homeless. Secondary effects included avalanches on Mount Everest that killed 19 people, blocked roads hampering relief efforts, and lost harvests leading to malnutrition. International responses included search and rescue teams from the UK, financial support from India and China, and temporary housing construction.

UK Flood and Coastal Management

York uses several strategies for flood management. The Foss Barrier is activated when the River Ouse reaches 7.8m, using eight pumps to transfer water. Clifton Ings serves as a natural floodplain capable of storing 2.3 million cubic metres of water. Leeman Road benefits from flood banks and an improved sewage system.

The River Tees in Northeast England demonstrates classic river features as it flows from its source in the Pennine Hills to the North Sea. It features High Force waterfall and gorge in its upper course, meanders and levees in its middle course near Darlington, and a floodplain in its lower course.

🌊 Effective flood management often combines "hard" engineering (like barriers and pumps) with "soft" approaches that work with natural systems!

The Holderness coastline showcases different coastal defences to manage erosion. Flamborough headland, composed of resistant chalk, features stumps and blowholes from erosion processes. Various coastal towns employ different protection strategies: Withernsea uses sea walls and groynes, Mappleton has rock groynes to prevent longshore drift, Hornsea combines riprap and sea walls, while Kilnsea has implemented a managed retreat approach.

Natural Disaster Case Studies

Typhoon Haiyan struck the Philippines in November 2013 as a Category 5 storm with winds up to 275km/h and 15m waves. Primary effects included 6,300 deaths, 600,000 displaced people, and widespread crop destruction. Secondary effects impacted 14 million people through flooding, landslides, disease outbreaks, and loss of income for 6 million residents. International responses included search and rescue support from the USA, food aid, and financial assistance from various countries and the UN.

The 1995 volcanic eruption in Montserrat (West Indies) resulted in 19 deaths and forced the evacuation of 11,000 people. The UK Navy assisted with large-scale evacuation, and residents were granted full UK residency rights. New infrastructure including roads and an airport was built to support recovery.

🌋 Volcanic eruptions often create long-term challenges for local economies, particularly when tourism is disrupted, as seen in both Montserrat and Mount St Helens!

The 1980 Mount St Helens eruption in the USA occurred at a destructive plate boundary (subduction zone). It destroyed 250 homes and 47 bridges, claimed 57 lives, and severely impacted the local tourism economy. Response efforts included replanting millions of trees, building new tourist facilities, and providing financial support for rebuilding homes.

Coastal Landforms and Processes

Mass movement refers to the shifting of rocks and loose material down slopes due to gravity. This takes several forms: rock falls (sudden drops), landslides (rapid sliding), and rotational slumping $curved movement creating stair-like features$.

Coastline types significantly influence erosion patterns. Discordant coastlines have alternating bands of hard and soft rock perpendicular to the sea, forming distinctive headland and bay formations. Concordant coastlines feature rock bands parallel to the shoreline with more uniform erosion.

🏝️ Coastal features like arches and stacks tell a story of ongoing erosion - what looks permanent to us is actually part of a dynamic, ever-changing landscape!

Wave formation occurs when wind creates friction over water, generating swells that become more elliptical as they approach the shore until breaking. These waves shape dramatic coastal features through processes like hydraulic power (water pressure in cracks) and abrasion. Over time, these create wave-cut platforms, caves, arches, stacks, and eventually stumps as erosion continues.

Coastal protection uses both hard and soft engineering approaches. Hard engineering includes sea walls, rock armour, gabions (caged rocks), and groynes to trap sand. Soft engineering involves beach nourishment, regeneration, and more natural approaches that work with coastal processes rather than against them.