Water: Part 1 - The great water cycle

This article is part of a series of articles on the theme of water.

Introduction

The goal of this article is to introduce the concept of the great water cycle.

The great water cycle is a fundamental concept in understanding how water moves through the environment. It describes the continuous movement of water on, above, and below the surface of the Earth. This cycle is essential for maintaining life and regulating climate. It is a closed cycle, meaning that water is constantly recycled and reused, rather than being lost or destroyed.

Schema

Illustrative image showing the big water cycle, with the different steps of the cycle

Fun facts

🧂 97% of the Earth's water is salt water.
🚰 3% of the Earth's is potable water.
🧊 66% of the Earth's potable water is ice.
💧 33% of the Earth's potable water is ready to be used.

Illustrative image showing the repartition of water on Earth, potable, ice, and salt water

Lexique

Water cycle steps

Precipitation : Rain, snow, sleet, or hail that falls from the atmosphere to the Earth's surface.
Runoff : Water that flows over the ground surface and returns to bodies of water, such as rivers, lakes, and oceans.
Infiltration : The process by which water on the ground surface enters the soil.
Evaporation : The process by which water changes from a liquid to a gas or vapor.
Condensation : The process by which water vapor in the air cools and changes back into liquid water, forming clouds.

Topography

Watershed: A Wathershed is an area of land that drains rainwater or snowmelt into a single body of water, such as a river, lake, or ocean.
Upstream : The area of land that is located higher in elevation than a specific point in a river or stream. Found at the top of the watershed
Downstream : The area of land that is located lower in elevation than a specific point in a river or stream. Found at the bottom of the watershed

These 3 concepts are important to understand since, the water flow form the upstream to the downstream, this means that the water used by an upper city is cleaner that the downstream city. I'm really sorry the the inhabitant or Rouen, they are drinking the already used water of the inhabitant of Paris (Thankfully for them this is not exactly true, we will explore in another article exactly why)