Exploring Rivers and Streams

What is erosion in the context of rivers?

• Erosion refers to the chemical breakdown of water in rivers.

• Erosion is the process by which river water wears away land and rocks, transporting sediment downstream.

• Erosion is the process of planting trees along riverbanks.

• Erosion is the accumulation of sediment at the river's mouth.

How does water flow affect erosion on riverbanks?

• Water flow decreases erosion by stabilizing soil on riverbanks.

• Water flow increases erosion on riverbanks by removing soil and sediment due to higher velocity and turbulence.

• Erosion on riverbanks is unaffected by water flow.

• Higher water flow leads to the deposition of sediment on riverbanks.

What is deposition in relation to rivers?

• Deposition is when rivers speed up and erode the riverbank.

• Deposition occurs when rivers evaporate water and leave sediments behind.

• Deposition is the process by which rivers drop sediments when their flow velocity decreases.

• Deposition is the process of rivers collecting water from rainfall.

How does sediment get deposited on riverbanks?

• Sediment is carried away by strong currents to the ocean.

• Sediment is deposited only during heavy rainfall.

• Sediment accumulates on riverbanks due to evaporation of water.

• Sediment gets deposited on riverbanks when the river's current slows down, allowing particles to settle.

What features are commonly found in the upper course of a river?

• Lakes and ponds

• V-shaped valleys, waterfalls, rapids, narrow channels, steep gradients.

• Meandering curves

• Wide floodplains

What is a V-shaped valley and where is it found?

• A V-shaped valley is found in mountainous or hilly regions, formed by river erosion.

• A V-shaped valley is found in deserts, formed by sand erosion.

• A V-shaped valley is found in flat plains, formed by wind erosion.

• A V-shaped valley is a type of lake formed by glacial activity.

How do waterfalls form in the upper course of rivers?

• Waterfalls are created by the freezing of water in cold climates.

• Waterfalls occur when rivers flow over flat terrain without any obstacles.

• Waterfalls are formed by the accumulation of sediment in river bends.

• Waterfalls form due to erosion of softer rock beneath harder rock, creating a ledge over which water cascades.

What are the characteristics of the middle course of a river?

• Straight channel, high gradient, no meandering, erosion on all banks, sediment deposition throughout the channel.

• Narrow channel, steep gradient, minimal meandering, sediment deposition on outer banks, erosion on inner banks.

• Very deep channel, flat gradient, constant meandering, erosion only at river mouth, sediment deposition only at river source.

• Wider channel, moderate gradient, increased meandering, erosion on outer banks, sediment deposition on inner banks.

How does the river's speed change from the upper to the lower course?

• The river's speed increases from the upper to the lower course.

• The river's speed fluctuates randomly without a pattern.

• The river's speed remains constant throughout its course.

• The river's speed decreases from the upper to the lower course.

What features are typical of the lower course of a river?

• Straight river path, high elevation, rapids

• Narrow riverbed, fast flow, waterfalls

• Steep banks, rapid currents, canyons

• Wide riverbed, slow flow, meanders, oxbow lakes, delta.