Weathering and Mass Wasting

Peru experiences both chemical and physical weathering due to its diverse geography.

• Carbonation: Rainwater dissolves limestone in mountainous areas.
• Hydrolysis: Breaks down minerals in humid regions like the Amazon.
• Freeze-thaw: Cracks rocks in the Andes Mountains.

Mass wasting (landslides) occurs frequently because of steep slopes, heavy rainfall, and earthquakes.

Major Event: In 1970, an earthquake triggered an avalanche from Mount Huascarán, burying the town of Yungay and killing ~20,000 people.

Government Response:

• Early warning systems
• Landslide monitoring
• Building restrictions
• Emergency planning

Water Erosion

Major Rivers

• Amazon River: Source in Andes, ~6,400 km long, largest discharge in the world, meandering channel.
• Ucayali River: Braided/meandering, major Amazon tributary.
• Marañón River: Flows through canyons, used for hydroelectric power.

Impacts

• Loss of farmland
• Flooding
• Damage to infrastructure
• Displacement of communities

Government Solutions

• Levees and flood barriers
• Riverbank stabilization
• Reforestation
• Flood monitoring

Wind Erosion

Wind erosion mainly occurs along Peru’s coastal deserts.

• Sand dunes form from strong coastal winds
• Common in Nazca and Paracas regions

Government Actions:

• Planting vegetation to stabilize sand
• Protecting desert areas

Deserts and Desertification

Major Deserts

• Sechura Desert: Reg (gravel desert), largest in Peru
• Nazca Desert: Reg + hamada (rocky desert), home of Nazca Lines

Desertification Issues:

• Climate change
• Overgrazing
• Deforestation

Government Solutions:

• Reforestation
• Sustainable farming
• Water conservation

Glaciers

Peru has the largest number of tropical glaciers, mainly in the Andes (Cordillera Blanca).

Importance

• Water supply
• Agriculture
• Hydropower

Problems

• Glacier melting due to climate change
• Water shortages
• Flood risks from glacial lakes

Glacial Features

• U-shaped valleys
• Glacial lakes
• Moraines