If you are asking what is the hydrological cycle then you are in the right place. In this article I will teach you all about the hydrological cycle, also known as the water cycle.
- Why do we need to understand the hydrological cycle?
- What is the hydrological cycle? The official answer
- What is the hydrological cycle? A SIMPLE explanation
- What is the hydrological cycle: Stores
- What is the hydrological cycle? Inputs
- What is the hydrological cycle? Outputs
- What is the hydrological cycle? Flows
- The 7 stages of the hydrological cycle
- The two types of hydrological cycle
- What is the hydrological cycle- FAQs
- What is the hydrological cycle: To conclude
Why do we need to understand the hydrological cycle?
Understanding the hydrological cycle is essential for managing water resources and predicting the impacts of climate change. In tourism, we use water A LOT, so it is imperative that we understand how water works and how to make best use of it.
To put it simply, the hydrological cycle is the movement of water between the atmosphere, land, and oceans. Why is this important? Because it is essential for sustaining life on Earth! And as the world’s population continues to grow and climate change impacts become more severe, understanding the hydrological cycle becomes increasingly important.
Whether you are a primary school student wishing to gain a basic understanding of how the water cycle works, you are studying the hydrological cycle as part of an A Level geography course or you are simply interested to learn more about one of the most important geographical cycles in our world, I have you covered in this article.
Keep reading to find out the answer to the question ‘what is the hydrological cycle’ and learn all about how the water cycle works…
What is the hydrological cycle? The official answer
Lets start this article by looking at an official explanation of what the hydrological cycle is. Whilst this is the way that the water cycle is often explained in geography books, I do understand that this isn’t always easy to understand, particularly if learning about the water cycle is new to you.
So, if you want a quick answer to the question ‘what is the hydrological cycle’ then read below. If you want this broken down into simpler terms then scroll down to the next section.
An official explanation of the hydrological cycle is as follows:
The hydrological cycle is a complex system that involves a variety of linked processes. Precipitation patterns and types, such as orographic, frontal, and convectional, are the primary inputs into the hydrological cycle. Orographic precipitation occurs when moist air is forced upward over a mountain range, while frontal precipitation is the result of a boundary between two air masses of different temperatures and moisture content. Convectional precipitation, on the other hand, is the result of the sun’s heating of the Earth’s surface causing air to rise and cool, resulting in the formation of clouds and subsequent rainfall.
Once precipitation occurs, it can follow a variety of paths. Interception occurs when precipitation is intercepted by vegetation or other surfaces and evaporates or is taken up by the vegetation. Infiltration occurs when precipitation seeps into the soil and is stored in the soil’s pore spaces. Direct runoff occurs when precipitation is unable to infiltrate the soil and flows overland, while saturated overland flow occurs when the soil becomes saturated with water and cannot absorb any more. Throughflow occurs when water moves through the soil and is stored in the subsurface, and percolation occurs when water moves through the soil and enters the groundwater system. Groundwater flow refers to the movement of water within an aquifer.
Finally, the outputs of the hydrological cycle include evaporation, transpiration, and channel flow. Evaporation is the process by which water changes from a liquid to a gas, and transpiration is the process by which plants release water vapor into the atmosphere. Channel flow occurs when water moves through streams and rivers, eventually reaching the oceans and completing the hydrological cycle. Overall, the hydrological cycle is a complex system that involves a variety of inputs, flows, and outputs, and understanding this system is critical for managing water resources and predicting the impacts of climate change.
What is the hydrological cycle? A SIMPLE explanation
Did the above explanation confuse you a little? Fear not, you are not alone! Lets break this down a bit more…
The hydrologic cycle is all about how water moves around the Earth. It starts with water on the ground that goes up into the sky and comes back down again as rain or snow.
There are lots of different things that happen in this cycle, but some of the most important are:
- Evaporation
- Transpiration
- Condensation
- Precipitation
- Runoff
These things happen over and over again, creating a cycle that keeps the water moving around our planet. It’s really important to understand this cycle so that we can take care of our water resources and make sure there’s enough clean water for everyone and everything on Earth.
Now lets take a deeper look at the different aspects of the hydrological cycle…
Evaporation
Evaporation is when a liquid, like water, turns into a gas, like steam. It happens when the liquid gets really hot and needs to cool down. The heat energy can come from the sun, the air, or even from our own bodies when we sweat.
We’ve all felt evaporation happen before! When we exercise or it’s really hot outside, our bodies start to sweat. This is our body’s way of cooling down by evaporating the sweat on our skin. It’s the same thing that happens when we get out of the shower or the pool and feel cool – it’s because our body heat is evaporating the water on our skin.
So, evaporation is an important way that water moves around in the world. Without it, we wouldn’t have clouds, rain, or any of the other things that water does to help plants and animals survive.
Transpiration
Transpiration is when plants lose water through tiny holes on the undersides of their leaves called “stomata”. These holes are connected to special parts of the plant that help it grow.
Most of the time, transpiration happens without the plant even trying – it just happens naturally because of how humid the air is and how much water is in the soil.
When a plant loses water through transpiration, only a tiny bit of it (like 1%) is actually used by the plant to grow. The rest of the water goes into the air around the plant.
This might not sound very important, but transpiration actually helps to create clouds and rain. It’s also really important for animals (including humans!) because we all need water to survive. Without transpiration, plants would dry up and die, and we wouldn’t have enough water to drink or grow our food.
Condensation
Condensation is when water vapor in the air turns into tiny drops of liquid. You can see it happening when dew forms on the grass in the morning, or when clouds appear in the sky.
Condensation doesn’t happen because it’s a certain temperature outside, but because there’s a difference in temperature between the air and something else. That something else could be a cold drink can or bottle, or even the ground or a plant. When the air is cooler than that thing, the water in the air turns into drops on the surface.
When water vapor turns into liquid, it gives off heat energy. This energy can help create big storms like hurricanes.
Condensation is really important for the planet because it helps to make rain, which helps plants grow and gives us water to drink. So, even though you might not think about it much, condensation is actually a really cool and important part of how the world works!
Precipitation
Precipitation is what happens when tiny drops of water in the clouds join together and become too heavy. Then they fall down to the ground as rain, snow, hail, or sleet.
Rain is the most common type of precipitation, but sometimes it gets so cold in the clouds that the water freezes and becomes snow or hail.
When it rains or snows, it helps to water plants and fill up rivers and lakes with fresh water. In fact, precipitation is the main way we get fresh water on Earth. Every year, the world gets about 38½ inches (980 mm) of precipitation. That’s a lot of water!
Runoff
Runoff is what happens when there is too much rain and the ground is too wet to soak it up. This extra water then flows into rivers and lakes. When the water is in these rivers and lakes, it can evaporate and become part of the atmosphere again. But if the water has nowhere else to go, like in a lake with no outlet, it can become salty as the water evaporates and leaves the salt behind. Eventually, the water evaporates and goes back into the air and the cycle starts again. Some of the water goes into the ground and gets used by plants.
What is the hydrological cycle: Stores
In order to fully understand howe the hydrological cycle works, we must also understand the concept of stores.
In the hydrological cycle, stores refer to the different places where water can be found and stored. There are several main stores in the hydrological cycle, including oceans, glaciers, rivers, lakes, groundwater, and the atmosphere.
The oceans store the majority of the Earth’s water and are a key part of the water cycle. Glaciers and ice caps store water in frozen form, and they can release water into the system through melting. Rivers and lakes store water temporarily, with water flowing in and out of them depending on precipitation and other factors.
Groundwater is water that is stored underground in soil and rocks, and it can be accessed through wells and other forms of groundwater extraction. Finally, the atmosphere is a store of water in the form of water vapor, which can be released as precipitation when conditions are right. All of these stores work together in the hydrological cycle to ensure that water is constantly being circulated and redistributed across the planet.
Here are some interesting facts about stores in the hydrological system:
- 97% of all water on Earth is stored in Oceans
- The remaining 3% is fresh water
- The majority of fresh water is stored in ice caps and glaciers (68.7% of all freshwater)
- 30.1% is stored as groundwater. Just 0.3% is stored as surface water
What is the hydrological cycle? Inputs
Inputs are also an important element of the hydrological cycle, but what are inputs exactly?
In the hydrological cycle, an input refers to any form of water that enters the cycle from outside sources. This can include precipitation such as :
- Rain
- Snow
- Sleet
- Hail
- Irrigation
- Water releases from reservoirs
Inputs are very important for the water cycle because they are the beginning of it all.
They decide how much water will be available for different things like soaking into the ground, flowing on the surface, or turning into gas. The amount of inputs and where they happen can affect how much water we have to use, especially in places where water is already hard to find or where the weather is changing.
What is the hydrological cycle? Outputs
An output is like the ending of something or what comes out of it. In the hydrological cycle, an output is the water that leaves the cycle and goes somewhere else.
For example, when it rains and water flows into a river, that’s an output from the cycle.
The output can also be the water that goes back into the atmosphere through evaporation or transpiration.
Outputs occur in the following forms:
- Evaporation: the process by which moisture is lost directly into the atmosphere from water surfaces, soil and rock.
- Transpiration: the biological process by which water is lost from plants through minute pores and transferred to the atmosphere.
- Discharge (channel flow): into another, larger drainage basin, a lake or the sea.
What is the hydrological cycle? Flows
In order to understand what is the hydrological cycle we must also understand the role of flows.
In the hydrological cycle, flows refer to the movement of water from one place to another. Examples include water moving through:
- Rivers
- Streams
- Underground aquifers
The amount and direction of flows can be affected by factors such as the slope of the land, the amount of precipitation, and the presence of human-made structures such as dams and canals.
The movement of water through flows is an important part of the water cycle as it helps to distribute water to where it is needed for plants, animals, and people to use.
The 7 stages of the hydrological cycle
There are at least seven different flows that are important in transferring the precipitation that has fallen on the land into the drainage network, this is known as the 7 stages of the hydrological cycle. Lets take a look at what happens at each stage…
Interception: This is when plants and soils hold onto water that falls on them, which is later used by plants or evaporated back into the atmosphere. This helps to reduce the amount of water that reaches the ground, and allows plants to access water they need to grow.
Infiltration
Infiltration is when water soaks into the soil. Infiltration is important for recharging groundwater and keeping the soil moist, which helps plants grow and prevents erosion.
Percolation
Percolation is when water moves through the soil and into permeable rocks below. This helps to recharge aquifers and create underground water reserves.
Throughflow
Throughflow is when water moves laterally through the soil downhill to rivers and streams. It helps transport water and recharge groundwater aquifers.
Groundwater flow
Groundwater flow is the slow movement of water through porous rocks. It’s important for wells, springs, and the baseflow of rivers and streams.
Surface runoff
Surface runoff is the act of water flowing over the ground surface and can cause erosion and transport pollutants to rivers and lakes.
River or channel flow
River or channel flow is the act of water flowing through a river or stream, and eventually to the ocean, where it evaporates and begins the hydrological cycle again.
The two types of hydrological cycle
Something that many people do not realise is that there are actually two types of hydrological cycle, one is an open system and the other is a closed system. Lets take a look at what this means…
Global hydrological cycle
Water on Earth doesn’t disappear or magically appear. It is always here and moves between the oceans and the atmosphere.
We call this the global hydrological cycle.
The global hydrological system is like a giant recycling system for water! The water moves around in a circle, and nothing is added or taken away. It is a closed system.
Local hydrological cycle
The global hydrological system is broken down into smaller, local systems, known as drainage basins.
A drainage basin is an area of land where water is collected by a river and its smaller rivers. The water can come from the ground or the surface.
There is a line called a watershed that separates different drainage basins. This line is usually on high ground. If it rains or snows on one side of the line, the water will flow into the river on that side. If it rains on the other side of the line, the water will flow into a different river.
A local hydrological cycle is an open system, meaning that water can enter or leave the cycle.
Factors influencing the drainage basin
The drainage basin can be influenced by several physical factors, which can affect the amount and distribution of water within the system. Some examples of these physical factors include:
- The size and shape of the basin
- The type and permeability of the soil and rock
- The vegetation cover
- The slope and topography of the land
- The climate and weather patterns
Some things like mountains, the size of the land, and temperature can change how much rain falls, how much water goes into the ground, and how fast water moves through the basin.
Humans can also change these things by building cities, cutting down trees, and farming.
This can affect how much water goes into the ground, how much runs off, and how fast it moves.
What is the hydrological cycle- FAQs
Before we end this article about answering the question ‘what is the hydrological cycle’, lets answer a few of the most common questions.
What is the hydrological cycle?
The hydrological cycle is the continuous circulation of water between the Earth’s atmosphere, oceans, and land surface.
How does the hydrological cycle work?
The hydrological cycle works by water evaporating from the Earth’s surface and rising into the atmosphere. This water then condenses into clouds and falls back to the surface as precipitation, which can take the form of rain, snow, sleet, or hail. Once on the surface, the water either evaporates again, runs off into rivers and streams, or infiltrates into the ground, where it can be stored as groundwater.
Why is the hydrological cycle important?
The hydrological cycle is important because it sustains life on Earth by providing fresh water to plants, animals, and humans. It also regulates the Earth’s climate by transporting heat from the equator to the poles and distributing it around the globe.
What are the main components of the hydrological cycle?
The main components of the hydrological cycle are evaporation, precipitation, infiltration, runoff, and groundwater flow.
What factors can affect the hydrological cycle?
Physical factors such as temperature, humidity, wind, and topography can all affect the hydrological cycle by influencing the rate of evaporation and precipitation, as well as the amount of water that infiltrates or runs off the surface. Human activities such as deforestation, urbanization, and agriculture can also alter the hydrological cycle by changing the physical characteristics of the landscape.
How long does the hydrological cycle take?
The hydrological cycle is a continuous process that operates on various time scales, from minutes to millions of years. Some components of the cycle, such as evaporation and precipitation, can occur on a daily or seasonal basis, while others, such as groundwater flow, can take thousands of years to complete.
What is the role of the ocean in the hydrological cycle?
The ocean plays a critical role in the hydrological cycle by storing vast amounts of water and releasing it through evaporation. Approximately 86% of the global evaporation and 78% of the global precipitation occur over the ocean, making it a key driver of the cycle.
What is the hydrological cycle: To conclude
As you can see, the hydrological cycle is extremely important to the health of our planet. We need water to exist, so it is imperative that we understand how the hydrological cycle, also known as the water cycle, works and how to maintain a healthy hydrological cycle on our planet- I have several articles related to this that I am sure you will also find interesting: