Question 1: Describe the main stages of a river's journey from its source to its mouth. Include at least three key stages and their characteristics.

Answer: The main stages are: 1. Source - where the river begins, often in the mountains, with steep slopes; 2. Course through the upper course - characterized by steep gradient, rapid flow, and erosion; 3. Middle course - gentler slope, wider river, with both erosion and deposition; 4. Lower course - very wide and slow-moving, with significant deposition forming features like floodplains and deltas; 5. Mouth - where the river meets the sea or lake.

Question 2: Explain how vertical and lateral erosion shape the landscape of a river's upper and middle courses respectively.

Answer: Vertical erosion occurs mainly in the upper course, where the river cuts down into the landscape, creating steep valleys and waterfalls. Lateral erosion occurs more in the middle course, where the river widens its valley through side erosion, forming features like meanders.

Question 3: Identify and describe two landforms created by erosion in river valleys.

Answer: Two landforms created by erosion are waterfalls, formed where a river flows over a vertical drop due to resistant rock layers, and V-shaped valleys, created by vertical erosion cutting into the landscape during the upper course.

Question 4: Identify and describe two landforms created by deposition in river valleys.

Answer: Two landforms created by deposition are floodplains, which are flat areas of land beside the river that are periodically flooded, and deltas, formed when a river deposits its load as it enters a standing body of water, creating a triangular landform.

Question 5: Describe how a meander forms in a river. Include the processes involved.

Answer: A meander forms when the river erodes the bank on the outer curve through lateral erosion, creating a bend. Simultaneously, deposition occurs on the inner bank where the flow is slower. Over time, these processes cause the bend to become more pronounced, creating a winding curve in the river.

Question 6: Sketch a diagram of a river showing a meander, label the main features such as the outer bank, inner bank, point bar, and cut bank.

Answer: A correct sketch would show a winding river with a pronounced bend. The outer bank of the bend should be labeled as the 'cut bank' (erosion site), and the inner bank as the 'point bar' (deposition site). The river should flow through the middle of the sketch.

Question 7: Explain the difference between a floodplain and a delta. How are they formed?

Answer: A floodplain is a flat area of land beside a river that floods periodically, formed through deposition during floods. A delta is a landform at the mouth of a river where it deposits its load as it enters a standing body of water, forming a triangular or fan-shaped area.

Question 8: What is the significance of a river's estuary, and how does it form?

Answer: An estuary is a coastal area where freshwater from the river mixes with saltwater from the sea. It forms where the river meets the ocean or sea, creating a unique and productive environment that supports diverse ecosystems.

Question 9: Discuss how human activities such as dam construction and urbanization can impact river systems.

Answer: Dams can regulate flow, reduce sediment transport, and disrupt ecosystems upstream and downstream. Urbanization increases surface runoff, leading to higher flood risks and pollution, and can cause river channel modifications that affect natural processes.

Question 10: Draw a cross-section of a river valley showing the river, floodplain, and valley sides. Indicate the flow direction.

Answer: A correct cross-section would depict the river flowing from left to right, with the river channel in the middle, flanked by gently sloping valley sides, and a flat floodplain on either side of the river. The flow direction should be indicated with an arrow.