Study: Human Constructions Block Majority of World’s Free-Flowing Rivers

Category: Science/Environment


Unlocking Word Meanings

Read the following words/expressions found in today’s article.

  1. disrupt / dɪsˈrʌpt / (v) – to break the flow or process of something

    Some strokes happen when something disrupts the flow of blood to the brain.

  2. aerial / ˈɛər i əl / (adj) – seen from above, usually on an airplane

    An aerial view of the forest revealed that there’s a lake hidden in the midst of all the trees.

  3. obstruction / əbˈstrʌk ʃən / (n) – something that prevents a process from continuing

    Obstructions such as plastics and other trash prevented water from flowing through the pipe.

  4. scarce / skɛərs / (adj) – not many or not enough

    The world’s supply of oil is gradually becoming scarce.

  5. reservoir / ˈrɛz ərˌvwɑr / (n) – a place where water is stored

    The reservoir is capable of supplying water to the entire city.


Read the text below.

A recent study has revealed that nearly 66% of the world’s longest rivers no longer run free due to man-made structures that disrupt their flow.

A team of researchers from the World Wildlife Fund (WWF) and other organizations evaluated the status of various rivers worldwide. The team used aerial images and satellite data to comprehensively map out rivers and examine how they flow.

Findings of the study showed that only about 37% of the world’s 246 longest rivers flow without any obstructions. The team discovered that long free-flowing rivers have become scarce in more developed and heavily populated places, including the United States and China. Only remote areas such as the Arctic and the Amazon still have many rivers that still run free.

Furthermore, the study found that free-flowing rivers are gradually disappearing due to economic development. The construction of dams, reservoirs, roads, and other infrastructures is mainly responsible for obstructing connections in river systems.

The researchers warned about the negative impacts of obstructions in free-flowing rivers. With such man-made facilities, the food supply for humans and animals decreases. Moreover, rivers become less effective in mitigating droughts and floods.

To prevent further problems in the ecosystem, the researchers emphasized the importance of protecting the planet’s remaining free-flowing rivers. The researchers suggested that governments and international organizations use the study’s data to find better ways to manage rivers.  They also hope that the findings will be used in creating new local and global policies for maintaining and restoring river conditions. Recommendations from the researchers include dam relocation and removal in some of the affected areas.

Viewpoint Discussion

Enjoy a discussion with your tutor.

Discussion A

• What do you think would happen if all rivers in the world become obstructed with man-made structures? Discuss.
• If you were a policymaker, what would you suggest to ensure that the world’s remaining free-flowing rivers are protected (e.g. policies about building facilities in rivers)? Discuss.

Discussion B

• Aside from obstructing rivers, in what other ways has economic development affected the environment? Discuss.
• Do you think that building structures on natural landscapes (e.g. rivers, oceans, mountains) should be stopped completely? Why or why not?