Question 1: Describe the process of hydraulic action and how it contributes to river erosion.

Answer: Hydraulic action involves the force of moving water compressing air into cracks in the riverbank or bed, which gradually wears away the material and causes erosion.

Question 2: Explain the difference between a v-shaped valley and a gorge formed by river erosion.

Answer: A v-shaped valley is a steep-sided valley with a narrow floor created by river erosion during the river's youthful stage, while a gorge is a deep, narrow valley with steep sides formed by the continued erosion of a river cutting through resistant rock.

Question 3: Identify and describe three features commonly found in the middle course of a river.

Answer: Features in the middle course include meanders (curves in the river), slip-off slopes (deposits on the inside of meanders), and floodplains (flat areas prone to flooding).

Question 4: Explain how a river's velocity affects the type of erosion it performs.

Answer: Higher velocity increases the river's ability to erode its banks and bed through processes like hydraulic action and abrasion, leading to more significant erosion.

Question 5: Describe what a delta is and how it forms at the mouth of a river.

Answer: A delta is a landform created when a river deposits its sediment as it enters a standing body of water, such as a sea or lake, forming a triangular or fan-shaped area of land.

Question 6: Sketch a diagram showing the stages of a river from its source to its mouth, including key features like waterfalls, meanders, and floodplains.

Answer: A correct sketch would show a river starting in the uplands with a steep gradient, features like waterfalls in the upper course, meanders in the middle course, and a delta or estuary at the mouth, with labels.

Question 7: Explain the difference between lateral and vertical erosion, providing examples of where each might occur in a river's course.

Answer: Vertical erosion deepens the river channel and occurs mainly in the upper course, creating steep valleys. Lateral erosion widens the river valley and mainly happens in the middle and lower courses, forming broad floodplains.

Question 8: Describe how a floodplain is formed and its significance to human settlements.

Answer: A floodplain is formed by the deposition of sediments during flooding, creating flat, fertile land suitable for agriculture and settlements, but also prone to flooding.

Question 9: Draw a cross-section of a river valley showing the river, valley sides, and floodplain. Label each part.

Answer: A correct sketch would show the river flowing in the center, with steeper valley sides on either side, and a flat floodplain extending beyond the valley sides, all labeled.

Question 10: Explain how human activities such as dam construction and river straightening can impact natural river processes.

Answer: Dams can reduce sediment flow and alter flow regimes, impacting ecosystems downstream. River straightening speeds up water flow, increasing erosion and flood risk downstream.