Skip main navigation

Stages of the water cycle

Watch Dr Michael Singer describe the first stages of the water cycle and the concepts of precipitation, evaporation and transpiration.
6.6
Doesn’t really matter how water got to Earth. What’s important is how water functions on planet Earth, and how much water there is in particular regions. This is what affects the health and well-being of human societies, and also the functioning and health of ecosystems around the planet. The water cycle is made up of different stores of water and the movement between those stores. We’ll begin our discussion of the water cycle with precipitation. Precipitation is the delivery of water from the atmosphere to the Earth’s surface. This happens through a process called condensation, where water molecules in the atmosphere– in clouds– collect into larger and larger water droplets, such that they have enough mass that they start to fall out of the sky.
66.2
Precipitation can fall as snow, as hail, as sleet, or as rain. And rain can be very heavy or it can be a light drizzle. But ultimately, all of those phases of precipitation deliver water to the land surface. Once the water arrives at the land surface, that water has different possible pathways. Some of that water can infiltrate into soils. Some will evaporate back into the atmosphere. Some will go into the deeper soil surface and recharge the groundwater within a region. Some of the water that ends up in the soil will be taken up by plant roots and returned to the atmosphere through a process called evapotranspiration. Evaporation is the main process of returning water to the atmosphere from the Earth’s surface.
132.6
It occurs in three different ways. The first process is the movement of water from open water bodies– lakes, oceans, and rivers– and returning that water to the atmosphere. That happens once the water surface is heated up enough that the molecules on the surface can change phases from liquid to gas. And then they are delivered back into the atmosphere. So essentially, there’s a recycling of water that landed on Earth that gets returned back into the atmosphere. The second way that water can get back into the atmosphere is through evaporation of water within the soil. Some of the water, as I mentioned, can drain and infiltrate into deep layers within the soil.
189.9
But it represents a much smaller amount of the total water that’s delivered to the Earth’s surface. Plants take up water through their roots in the soil, and send that water up through their stems, and deliver it from their leaves back into the atmosphere. That process is called transpiration. So the sum total of all of these processes is called evapotranspiration.

In this video, Dr Michael Singer describes the first stages of the water cycle.

The water cycle is made up of different stores of water and the movement between those stores.

It include these processes:

Precipitation

This is the delivery of water from the atmosphere to the Earth’s surface

Evaporation

This is the main process of returning water to the atmosphere from the Earth’s surface.

Transpiration

This is when plants take up water through their roots in the soil, and send that water up through their stems, and deliver it from their leaves back into the atmosphere.

This article is from the free online

The Challenge of Global Water Security

Created by
FutureLearn - Learning For Life

Our purpose is to transform access to education.

We offer a diverse selection of courses from leading universities and cultural institutions from around the world. These are delivered one step at a time, and are accessible on mobile, tablet and desktop, so you can fit learning around your life.

We believe learning should be an enjoyable, social experience, so our courses offer the opportunity to discuss what you’re learning with others as you go, helping you make fresh discoveries and form new ideas.
You can unlock new opportunities with unlimited access to hundreds of online short courses for a year by subscribing to our Unlimited package. Build your knowledge with top universities and organisations.

Learn more about how FutureLearn is transforming access to education