Levees and Dams: Risks and Benefits

The lecture discusses the human impacts on water systems, focusing on dams and levees. It covers the benefits and drawbacks of dams, including water storage, flood prevention, and hydropower, while also addressing their economic and ecological impacts. The lecture also explores the function of levees in flood prevention and the challenges they face, especially in the context of climate change.

What are the two main human activities affecting natural water systems discussed in the lecture?

• Urbanization and mining

• Dams and levees

• Pollution and deforestation

• Fishing and agriculture

Which of the following is a benefit of dams mentioned in the lecture?

• Enhancing biodiversity

• Increasing fish population

• Water storage for dry seasons

• Reducing air pollution

What is a significant economic challenge associated with dam construction?

• Loss of tourism revenue

• High cost of building materials

• Maintenance and sediment dredging

• Increased fish migration

How do dams affect the natural sediment flow in rivers?

• They cause rivers to be starved of sediment

• They have no effect on sediment flow

• They create new sediment sources

• They increase sediment flow downstream

What is the primary purpose of levees as discussed in the lecture?

• To generate hydroelectric power

• To enhance recreational activities

• To create wider, deeper, straighter channels

• To increase fish migration

What is a major risk associated with levees over time?

• They become tourist attractions

• They increase water temperature

• They enhance biodiversity

• They will eventually overtop or break

What is one proposed solution to reduce the risk of levee breakage?

• Setting levees back from the river

• Increasing the number of levees

• Using stronger materials

• Building taller levees

What is a potential downside of setting levees back from the river?

• It decreases water quality

• It is considered wasted land by some

• It reduces agricultural productivity

• It increases the risk of flooding

Why might some people oppose moving levees back from the river?

• It involves losing land for agriculture or urban use

• It requires less maintenance

• It increases the risk of dam failure

• It is too environmentally friendly

What is a significant cost associated with moving levees back?

• Expensive restoration per river mile

• Reduced hydroelectric power

• Increased fish population

• Higher water temperatures