Main idea

To be able to sustain the natural level of self-purification ability of a river system, the riverbeds should have their natural morphology with wide riparian zones with vegetation and gravel islands, etc. Natural morphology and natural river banks enhance water retention, which increases the self-purification capacity of rivers.

Goal

To make sure that the students understand how important it is to maintain natural river morphology and the natural riparian area along its course for water purification processes.

Concepts

natural river morphology → water purification

Introduction: What Kind of River is Better in Cleaning Itself?

Let students repeat their findings from the previous lesson about different self-purification processes in rivers.

Activities in this lesson

What does a Sponge Have to do With Wetlands and Forests?
7.1.1
Subject: Art and craft, Biology, Chemistry, Geography, Health care and recreation
Age group: All, 4 - 6, 7 - 9, 10 - 12, 13 and up
Type of activity: Experiment
Number of participants: Team
Importance of Wetlands and Forests
7.1.2
Subject: Art and craft, Biology, Chemistry, Geography, Physics
Age group: All, 4 - 6, 7 - 9, 10 - 12, 13 and up
Type of activity: Experiment
Number of participants: Team
What do Permeable Surfaces Have to do with Purification?
7.1.3
Subject: Art and craft, Biology, Chemistry, Geography, Physics
Age group: All, 4 - 6, 7 - 9, 10 - 12, 13 and up
Type of activity: Experiment
Number of participants: Team
Ability of Our River to Clean Itself (self-purification capacity)
7.1.4
Subject: Biology, Chemistry, Geography, Physics
Age group: 10 - 12, 13 and up
Type of activity: Debate, Field activity
Number of participants: Individual, Team
Imagine Human Settlements Build in Harmony with Nature
7.1.5
Subject: Art and craft, Biology, Geography, Language, Social skills
Age group: 13 and up
Type of activity: Debate, Project
Number of participants: Team

Discussion: Our Future World

  • Ask students to think about climate change. What they know about this topic and how they think the topic of pollution and self-purification capacity of water systems is linked to climate change? (Climate change means increase of extreme events such as floods and droughts. In times of droughts, natural water systems are much more sensitive to pollution because their purification capacity is much lower. Measures taken to increase purification capacity of water systems also increase their resilience to floods, because wetlands function as sponges that retain flood water.)
  • Ask students to imagine our future world keeping in mind everything they have learned so far about climate change and self-regulating mechanisms of water systems.