Environmental Management - 0680 CIE

Flooding

Overview

Flooding is the most common natural hazard on the planet. Between 1995 and 2015 floods made up almost half of all weather-related disasters, affecting more than two billion people. A flood happens whenever water arrives faster than the land or a river channel can carry it away, so the river spills over its banks and drowns the floodplain. The causes are partly natural, such as heavy rain and steep slopes, and partly human, such as cutting down forests and paving over the ground.

In this lesson you will learn the physical and human causes of flooding, read a storm hydrograph to see how quickly a river responds to rain, and follow the Environmental Management chain of cause, impact and management. The deadly 2010 Pakistan floods provide a named example, and you will also see why, despite the danger, flooding brings real opportunities such as the fertile silt that has fed civilisations for thousands of years.

Objectives

6.3.1 Describe and explain the causes of flooding, limited to: (a) land relief (b) saturated soil, compacted soil and soil erosion (c) deforestation, agricultural practices and urbanisation (d) climate change: rise in sea level and increase in extreme weather events (e) storm surges and tsunamis.
6.3.2 Describe and explain the impacts of flooding on people and the environment, limited to: (a) damage to buildings and infrastructure (b) loss of crops (c) livestock and habitats (d) evacuation of people and livestock (e) landslides (f) contamination of drinking-water supplies (g) water-related disease (h) financial losses (i) human health.
6.3.3 Describe strategies for managing the impacts before, during and after flooding, limited to: (a) monitoring and warning (b) land use zoning (c) structure of buildings (d) disaster preparation (plans, drills, emergency supplies and emergency rescue teams) (e) evacuation (f) shelters (g) rebuilding of damaged areas (h) international aid.
6.3.4 Discuss the benefits and limitations of strategies for managing the impacts before, during and after flooding.
6.3.5 Describe and explain the opportunities provided by flooding to people, limited to: (a) deposition of nutrient-rich silt on farmland (b) recharge of surface water and ground water stores.

Lesson Note

More people are harmed by floods than by any other natural hazard, and the risk is rising as climate change brings heavier downpours and higher seas, and as cities spread over ground that once soaked up rain. Flooding is also unusual among hazards because so many of its causes are human, which means people can reduce the risk through better land use. That makes it ideal for the cause-impact-management answers the exam rewards.

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Lesson Evaluation

Congratulations on completing the lesson on Flooding. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

Flooding occurs when: A. A river's discharge exceeds the capacity of its channel B. The lag time of a river is very long C. Soil infiltration increases D. A river is in a wooded basin Answer: A
Which of the following is a human cause of flooding? A. Steep relief B. Heavy rainfall C. Urbanisation D. Saturated soil Answer: C
On a storm hydrograph, a short lag time and a steep rising limb indicate: A. A low flood risk B. A high flood risk C. A wooded basin D. High infiltration Answer: B
Which is an opportunity provided by flooding? A. Spread of disease B. Loss of crops C. Deposition of nutrient-rich silt D. Damage to infrastructure Answer: C
Afforestation to reduce flooding is an example of: A. Hard engineering B. Soft engineering C. Land-use zoning D. A storm surge Answer: B