Geography 101: Physical Geography Basics - Landforms Mountains Plateaus Plains Valleys Canyons Coastlines

What This Is

Landforms are the diverse features that shape our planet's surface. They are formed through various geological processes, such as tectonic activity, weathering, and erosion. Understanding landforms is crucial for grasping the dynamic nature of Earth's surface and how it changes over time. For instance, the formation of the Himalayas is a result of the collision between the Indian and Eurasian plates, which has created the world's highest mountain range.

Key Processes, Landforms & Theories

• Mountain Building (Orogenesis): The process of forming mountains through the collision of tectonic plates – the Himalayas are a classic example.
• Plateaus: Elevated areas of land formed through volcanic activity or erosion – the Colorado Plateau in the US is a notable example.
• Plains: Flat or gently sloping areas of land formed through erosion or deposition – the Great Plains in North America are a prominent example.
• Valleys: Low-lying areas of land formed through erosion or tectonic activity – the Grand Canyon is a famous example of a valley.
• Canyons: Deep, narrow valleys formed through erosion – the Fish River Canyon in Namibia is one of the largest canyons in the world.
• Coastlines: The interface between land and sea, formed through tectonic activity, erosion, and deposition – the Great Barrier Reef is a unique example of a coastline.
• Longshore Drift: Sediment is transported along a coast by an angled wave approach – responsible for the formation of spits like Spurn Head (UK).
• Subsidence: The sinking of the land surface due to tectonic activity or human activities – the city of Venice is a notable example.
• Uplift: The rising of the land surface due to tectonic activity or volcanic activity – the Tibetan Plateau is a prominent example.
• Delta Formation: The deposition of sediment at the mouth of a river, forming a delta – the Nile Delta in Egypt is a classic example.

Step-by-Step Application

1. Identifying Landforms from a Contour Map: Look for changes in elevation, such as peaks, valleys, and ridges, and use the contour lines to determine the shape and size of the landform.
2. Explaining the Formation of a Waterfall: A waterfall forms when a river flows over a steep drop in the landscape, such as a cliff or a fault line. The water flows over the edge, creating a plunge pool below.
3. Calculating River Discharge: Measure the cross-sectional area of the river and the velocity of the water to calculate the discharge (volume of water per unit time).
4. Interpreting a Diagram of a Coastline: Look for features such as bays, headlands, and spits, and use the diagram to determine the type of coastline (e.g., erosional, depositional, or a combination of both).

Common Misconceptions

• Misconception: Deserts are always hot.
• Correction: Deserts can be hot or cold, depending on the location and climate. For example, the Gobi Desert in Asia is cold and dry, while the Sahara Desert in Africa is hot and dry.
• Misconception: Water in a river flows faster on the inside of a meander.
• Correction: Water in a river flows faster on the outside of a meander, due to the increased velocity of the water as it flows around the bend.
• Misconception: Plate tectonics causes volcanoes everywhere.
• Correction: Plate tectonics is responsible for the formation of volcanoes at subduction zones, such as the Andes, but not everywhere. Volcanoes can also form at hotspots, such as Hawaii.

Exam / Short-Answer Tips

• Drawing and Annotating a Labelled Diagram: Use a ruler to draw the diagram, and label each feature clearly and concisely. Use arrows to indicate the direction of flow or movement.
• Tricky Distinctions: Be able to distinguish between weathering and erosion, hamada and erg, storm surge and tsunami, and other similar terms.
• Including Place-Specific Detail: Use specific examples from real-world locations to illustrate your answer, and explain how the process or landform is unique to that location.

Quick Practice Scenario

A river curves sharply, cutting into the outer bank while depositing sediment on the inner bank. Name the feature and explain the process.

Answer: Meander. The process is called lateral erosion, where the river flows faster on the outside of the bend, cutting into the outer bank, while depositing sediment on the inner bank.

Last-Minute Cram Sheet

• Landform: A natural feature of the Earth's surface, such as a mountain, valley, or coastline.
• Weathering: The breakdown of rock in situ, without movement.
• Erosion: The removal and transport of rock or soil.
• Plateaus: Elevated areas of land formed through volcanic activity or erosion.
• Plains: Flat or gently sloping areas of land formed through erosion or deposition.
• Valleys: Low-lying areas of land formed through erosion or tectonic activity.
• Canyons: Deep, narrow valleys formed through erosion.
• Coastlines: The interface between land and sea, formed through tectonic activity, erosion, and deposition.
• Longshore Drift: Sediment is transported along a coast by an angled wave approach.
• Subsidence: The sinking of the land surface due to tectonic activity or human activities.
• Uplift: The rising of the land surface due to tectonic activity or volcanic activity.
• Delta Formation: The deposition of sediment at the mouth of a river, forming a delta.