EARTH’S ARTERIES
Which is the longest river in the world? Learn 10 cool facts about rivers
Published on November 11, 2024
Image: Jamesthethomas5
Rivers are the arteries of our planet. By connecting lands, lakes, and the sea, they enable the circulation of nutrients, sediments, and living beings. And despite holding a very small percentage of the water on Earth, they sustain most of its life!
Here are 10 intriguing facts about rivers from across the world.
Rivers Shape the Earth
Image: Alex Shutin
Over millions of years, rivers have carved some of the most awe-inspiring landscapes on Earth. From the Grand Canyon at the Colorado River to the Three Gorges at the Yangtze River, waterways are powerful sculptors, shaping valleys, canyons, and deltas by eroding rocks at some points and depositing the resulting sediments further downstream. Without rivers, we would live on a very different planet!
The Lifeline of Civilization
Image: Xuan Nguyen
Throughout history, rivers have served as vital arteries for human civilization. The earliest human settlements first sprouted along river banks - like the Tigris and Euphrates, the Nile, the Indus, and the Yellow River - drawn by abundant food, fertile soil, natural resources, and access to water for drinking and agriculture. Currently, freshwater fisheries sustain up to 550 million people! Rivers also function as transportation routes, and borders between countries.
Biodiversity Hotspots
Image: Geranimo
Rivers are teeming with life, hosting a diverse array of plants, animals, and microorganisms. In fact, they are some of the most diverse ecosystems on the planet, sustaining more fish species than the sea! Rivers also serve as corridors for land-based wildlife, keeping animal populations healthy and helping preserve biodiversity.
Image: pine watt
A Never-Ending Cycle
Rivers play a crucial role in the water cycle, transporting vast quantities of water from land to sea. Every year, 38 trillion cubic meters of river water flow into the oceans! Most of this is actually rainwater, created through the evaporation of ocean water. Along their way, they also replenish groundwater reserves, nourishing ecosystems and sustaining human communities during dry spells.
Guardians of Water Quality
Image: Philipp Potocnik
Healthy rivers also act as natural filters, purifying water along their course and removing pollutants. Wetlands, floodplains, and riparian zones help trap sediment and absorb excess nutrients, safeguarding downstream water quality. This is why it’s so important to fight pollution and preserve rivers’ capacity for regeneration. When this filter fails, problems go downstream and end up in the ocean, silently accumulating and causing serious ecological imbalances.
The Power of Hydropower
Image: Cédric Dhaenens
Rivers are a potent source of renewable energy, driving hydroelectric dams that generate electricity. Nowadays, dams store one-sixth of the water flowing in rivers, and hydropower accounts for 16% of the world’s electricity. However, though they are considered a greener form of energy, if they are not adequately planned hydroelectric dams can come at great cost to river ecosystems and communities.
Cultural Crossroads
Image: Sneha Sivarajan
Rivers have long been cultural and spiritual symbols, revered by indigenous peoples and civilizations around the world. They feature prominently in myths, rituals, and religious beliefs, embodying concepts of life, renewal, and the divine. Rivers also create identity - there are at least 17 countries that are named after rivers, including India, Nigeria, Congo, and Belize! Moreover, they are hotspots for recreation, providing havens for birdwatching, camping, and hiking, drawing millions of visitors each year to their shores.
Threats to River Health
Image: Luke Oslizlo
Despite their importance, rivers face a myriad of threats, including pollution, habitat destruction, and overexploitation. It is currently estimated that at least 10,000 to 20,000 freshwater species have gone extinct or are on the brink of extinction. A staggering 37% of the world’s freshwater fish species are seriously threatened. Climate change exacerbates these challenges, leading to altered flow regimes, increased flooding, and habitat loss.
The Longest River
Image: Jordi Orts Segalés
Stretching over 4,130 miles, the Nile is not just the longest river in Africa but also the entire world. Originating from Lake Victoria in Uganda, it flows through eleven countries, including Egypt, where it empties into the Mediterranean Sea. From ancient times, the Egyptian and Sudanese kingdoms have heavily depended on the river and its annual cycles of flooding, and to this day most of the population and cities of Egypt lie along the valley of the Nile.
The Largest River by Discharge
Image: Nareeta Martin
The Amazon River in South America carries more water than any other river, accounting for approximately 20% of the total freshwater discharge into the oceans - it is estimated that every second, 84 olympic-sized pools are discharged into the sea from its mouth! It also has a massive basin, covering over 2.7 million square miles, most of which is part of the Amazon rainforest.
