Formation of Plains
Most plains are formed by rivers. As rivers flow down from mountains, they erode rocks and carry sand and silt. This material, called sediment, is deposited along the river banks and in lower areas.
Characteristics
- Flat Surface: Generally not more than 300 meters above sea level.
- Fertility: The deposited silt makes the land extremely fertile and ideal for agriculture.
- Navigation: Due to the gentle slope, rivers in plains are easy to navigate by boat.
Human Life in the Plains
Plains are the most densely populated regions in the world.
- Agriculture: Major crops like rice, wheat, maize, and cotton are grown here.
- The Gangetic Plain: Home to over 40 crore people (more than 1/4th of India’s population).
- Culture: Rivers in plains, such as the Ganga, are considered sacred. Their sources and confluences (meeting points) are sites for festivals and rituals.
Challenges
- High Population: Leads to pressure on resources.
- Pollution: High industrial and domestic waste.
- Groundwater Depletion: Excessive irrigation is causing water levels to drop.
Tip
The first great civilizations (like the Indus Valley and Mesopotamian civilizations) all started in fertile river plains because of the easy access to water and food.