Water Cycle – Definition, Stages, Implications, Diagram

Water cycle, also known as the hydrologic cycle, is a natural process that includes the continuous circulation of water throughout the Earth’s atmosphere, oceans, land, and underground. Understanding the water cycle is crucial for comprehending how water moves and is distributed across the planet. In this article, we will explain the various stages of the water cycle, including evaporation, condensation, precipitation, and transpiration, as well as the importance of this process in maintaining Earth’s ecosystems. 

What is the Water Cycle?

The cyclic movement of water within the earth and atmosphere, such process is known as Water Cycle. 

The water cycle is a continuous water circulation in the Earth-atmosphere system. The water cycle is also known as the Hydrologic or Hydrological Cycle. Evaporation, transpiration, condensation, precipitation, and runoff are the most significant processes in the water cycle. The state of water changes from one phase to the next during this process, while the total number of water particles remains constant. Water goes through a variety of processes, including evaporation, melting, and freezing, as well as sublimation, condensation, and deposition.

Water Cycle Diagram

The below diagram shows the various stages of the water cycle. The water state changes through various stages but the no. of water particles remains the same. 

Stages of Water Cycle

Water goes into various stages to complete the one water cycle. Following are the different stages present in the water cycles mentioned below.

Evaporation

The sun is both the most powerful source of energy on the planet and the primary cause of evaporation. When water molecules on the surface of water bodies become excited, they rise into the air and evaporate. Water evaporates when it is below its boiling point. The process of evaporation via the leaves of plants is known as evapotranspiration. As a result of this process, a large amount of water is released into the atmosphere.

Sublimation

Sublimation is the transformation of snow or ice into water vapour without becoming water. The most typical reasons are dry winds and low humidity. Sublimation can be visible on mountain peaks when the air pressure is extremely low. The process is aided by low air pressure, which requires less energy to convert snow to water vapour. Sublimation is also visible during the fogging phase of dry ice. The planet’s primary source of sublimation is the ice sheets that cover its poles.

Condensation

Because of the low temperatures at high altitudes, the water vapour that has accumulated in the atmosphere cools. These vapours condense into droplets of water and ice, which eventually condense into clouds. The temperature at which condensation occurs is known as the dew point. Temperatures can naturally approach or go below the dew point, especially at night. As a result, water droplets are sprayed on lawns, cars, and buildings every morning. Water droplets can form on the outside of a cold soda glass due to condensation. Warm air reaches its dew point and condenses when it comes into contact with a cold surface. Water droplets form on the glass or container because of condensation.

Precipitation

When the temperature rises above 0 degrees Celsius, the vapours condense into water droplets. In the absence of dust or other contaminants, however, it cannot condense. Water vapours stick to the particle’s surface as a result. When enough droplets form, it falls from the sky and onto the earth below, a process known as precipitation. Water droplets freeze and fall as snow or hail in extremely cold weather or when air pressure is extremely low.

Infiltration

Infiltration is the process through which rainwater is absorbed into the ground. The amount of water absorbed varies depending on the medium into which it was introduced. Rocks, for example, will hold substantially less water than soil. Groundwater can be transported by both streams and rivers. It’s possible, however, that it’ll simply sink deeper and form aquifers.

Runoff

If rainwater does not create aquifers, gravity transports it down mountain and hill slopes, finally forming rivers. Runoff is the term for this practice. Icecaps arise when precipitation surpasses the rate of evaporation or sublimation in colder climates. The world’s largest icecaps are found at the poles.

Implications of Water Cycle

• The weather is heavily influenced by the water cycle. The greenhouse effect will cause temperatures to rise.
• The Earth’s temperature would rise considerably if the evaporative cooling effect of the water cycle did not exist.
• The potential of the water cycle to filter the air is well established. Water vapours must connect with dust particles during the precipitation process. Raindrops collect water-soluble gases and contaminants, as well as dust when they descend from the sky in polluted cities.
• The water cycle is also connected with different biogeochemical cycles.
• Other life processes are also affected by the water cycle.

Impact of Rainfall on the Environment

• Rainfall or other forms of water precipitation provide water to many forms of life, either directly or indirectly.
• Water is utilised by plants after it falls to the Earth as rainfall. Plant roots absorb water, which flows up the plant stem column to the leaves. The leaves then collect sunlight and employ photosynthesis to produce sugar to feed the plants. All of this is due to the beneficial influence of rainfall.
• A lot of negative impacts occur when there is an excess of water in the form of rainfall. Excessive rain can harm plants and compact soil. Erosion eventually happens when soil becomes compressed.
• Flooding endangers human life, destroys houses, roads, and bridges, and wreaks havoc on cattle and crops. Rainfall can have an impact on forests.
• While some places may see more intense rainfall events, others may be affected by the reverse scenario of receiving less rainfall than previously measured. The impact of deforestation on the Brazilian Amazon is a classic illustration of this.

Climate Change and Water Cycle

Water evaporates from the land and sea, eventually returning as rain and snow to the Earth. Climate warming hastens the water cycle by causing more water to evaporate into the atmosphere as air temperatures rise. Warmer air can carry more water vapour, causing more violent rainstorms and major challenges like excessive flooding in coastal cities all over the world.

While some locations are seeing more severe storms, others are suffering dry air and even drought. As previously said, as the temperature rises, evaporation rises and soils dry out. When rain does fall, much of it washes off the hard ground into rivers and streams, leaving the land dry. More evaporation from the soil means a higher risk of drought.

Hydrological extremes are becoming more extreme as a result of climate change. As a result, hotspots and vulnerable areas form, necessitating challenging adaptation. Climate change’s negative effects on freshwater systems are quite likely to outweigh their benefits globally.

FAQs on Water Cycle

Q1: What is the water cycle?

Answer:

Water cycles continually in the Earth-atmosphere system throughout the water cycle, also known as the hydrologic cycle.

Q2: Why is the water cycle important?

Answer:

The water cycle is important because it helps to flow the water to plants, animals and to humans. It is also related to other biogeochemical cycles.

Q3: What is the age of the water cycle?

Answer:

The water cycle on the earth start 3.8 billion years ago during the time of evolution. Earth cooldowns itself via rainfall.

Q4: What are the major 4 steps in the water cycle?

Answer:

The 4 major steps of the water cycle are:

1. Evaporation
2. Condensation
3. Precipitation
4. Collection