In which river course are canyons formed?

1.7 Humans cause weathering when constructing roads primarily by clearing vegetation. Removing vegetation exposes the soil and underlying rock to the elements, increasing the rate of physical and chemical weathering.
The correct option is C.

• C) by clearing vegetation

1.8 Humans increase the rate of chemical weathering through vehicle emissions. These emissions release pollutants like sulfur dioxide and nitrogen oxides into the atmosphere, which contribute to acid rain. Acid rain then accelerates chemical weathering processes on rocks and structures.
The correct option is D.

• D) vehicle emissions

1.9 Canyons are deep, narrow valleys with steep sides, typically formed by strong vertical erosion. This type of erosion is most prominent in the upper course of a river where the gradient is steep and the water flows rapidly. The diagram shows steep, V-shaped valleys in the Upper Course.
The correct option is B.

• B) upper course

1.10 Feature 6 is located in the Upper Course of the river and depicts a deep, narrow valley with steep sides. This geological formation is known as a canyon.
The correct option is A.

• A) canyon

1.11 Feature 8 is a crescent-shaped body of water that has been cut off from the main river channel, which is meandering. This is a characteristic feature of an oxbow lake, formed when a meander loop is abandoned.
The correct option is A.

• A) oxbow lake

1.12 As identified in 1.11, feature 8 is an oxbow lake. According to the provided diagram, feature 8 is clearly located within the section labeled "Middle Course". Oxbow lakes typically form in the middle and sometimes lower courses of a river where meanders are prominent.
The correct option is A.

• A) middle course