Hydrosphere refers to the water that covers the Earth’s surface. Water covers approximately 71% of the earth’s surface or 361740000 square kilometres. It consists of all oceans, lakes, rivers, and groundwater. Because it regulates the climate and influences the distribution of plant and animal species, the hydrosphere is an important part of the Earth’s environment. The hydrosphere mainly consists of the Hydrological Cycle and Components of the Hydrosphere.
Hydrosphere Hydrological Cycle
The circulation of water within the Earth’s Hydrosphere in various states such as liquid, solid, and gaseous is known as the Hydrological cycle. It is also called the water cycle. It also refers to the continuous exchange of water between the land surface, oceans, and subsurface, as well as organisms. The existence of the hydrosphere is dependent on this significant phenomenon.
The Water cycle consists of four steps. Evaporation, condensation, precipitation, and surface run-off are examples of these processes. The sun’s heat causes water from lakes, oceans, and streams to evaporate. The oceans contain approximately 71% of the water on Earth. The remaining water is found in lakes, glaciers, ice caps, groundwater sources, soil, and various forms of life. Evaporation returns approximately 59% of the water that reaches the land to the atmosphere. Evaporation occurs in oceans as well as other locations. The process by which a liquid turns into a gas is called evaporation.
Water vapour carried away by hot air begins to cool as it rises above the earth’s surface. It eventually transforms into clouds. This is called condensation. When water condenses in the clouds, it becomes heavy and begins to fall back as snow or rain, depending on the temperature of the atmosphere. This is referred to as precipitation. When it rains, the soil absorbs a small amount of water, which becomes groundwater. The remainder flows through the hills and mountains and collects in various parts of the hydrosphere. This is referred to as surface run-off. The hydrosphere refers to the cycle of water through various states and stages.
Hydrological Cycle Diagram
Hydrological Cycle mainly consists of three stages i.e.Evaporation, Condensation and Precipitation.
Below is a detailed diagram of the Hydrological Cycle:
Any water storage area on Earth that holds liquid water is a part of the hydrosphere. As a result, the hydrosphere is made up of a diverse range of formations. There are four major components of the Hydrological cycle:
- Glacial water
- Atmospheric water vapour (Surface water, Groundwater)
The vast majority of the water on our planet is saltwater, and the oceans contain the vast majority of this saltwater. Oceans can be found at greater depths beneath the earth’s surface. Oceans, unlike continents, merge seamlessly and become difficult to distinguish. According to geographers, the earth’s five distinct oceans are the Indian, Pacific, Arctic, Atlantic, and Southern Oceans.
Any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids is referred to as fresh water. Although seawater and brackish water are specifically excluded, non-salty mineral-rich waters such as chalybeate springs are included. Freshwater is much less abundant than salt water and can be found in a variety of environments. Lakes, rivers, and streams are examples of surface freshwater sources.
3. Glacial Water
Glacial water is water that melts from glaciers. It normally occurs at the glacier’s base, but it can also form on, inside of, or beneath it. The world’s glaciers are thinning as Earth’s temperature warms, boosting freshwater discharges to all types of glacial lakes.
4. Atmospheric Water Vapour
Under typical atmospheric circumstances, water vapour is continuously created by evaporation and removed by condensation. It is less dense than most other air constituents and causes convection currents, which can lead to clouds. It is present in two forms:
Surface water: Any body of water found on the Earth’s surface is considered surface water, which includes both saltwater in the ocean and freshwater in rivers, streams, and lakes.
Groundwater: Water that seeps into the soil and is stored in large aquifers beneath the ground. This water can be accessed through the use of wells and motors.
The hydrosphere is of immense importance in the following ways:
1. An Important Component of Living Cells
A living organism’s cells are made up of at least 75% water. This promotes the cell’s normal functioning. The vast majority of chemical reactions occurring in living things involve substances dissolved in water. Without water, no cell can survive or perform its normal functions.
2. Water Provides Habitat to Flora and Fauna
The hydrosphere provides a habitat for a variety of plants and animals. Water dissolves many gases and ions, including CO2, O2, nutrients like ammonium and nitrite (NO-2) and other ions. The presence of these substances is critical for the existence of life in water.
3. Existence of Earth’s Atmosphere
The hydrosphere makes a significant contribution to the current state of the atmosphere. The earth’s atmosphere was extremely thin when it was first created. Helium and hydrogen were tightly packed in this atmosphere, just like they are now on Mercury.
Helium and hydrogen eventually vent off from the atmosphere. As the Earth cooled, the gases and water vapour produced became the current atmosphere. Other gases and water vapour were also released by the volcanoes and entered the atmosphere.
4. Fulfils Basic Human Needs
Water is used by humans in a number of ways. The most obvious use is drinking water, but we also use it for domestic purposes such as washing and cleaning, as well as in industries. Furthermore, we use water to generate electricity via hydropower.
5. Impact on the Earth’s Climate
The specific heat of the water is one of its distinguishing features. This indicates that water has a slow rate of heating and cooling.. It helps to regulate the temperatures on Earth so that they remain within an acceptable range for life to exist.
Hydrosphere Anthropogenic Impact
Human activities that are irresponsible are the primary cause of water source depletion and hydrosphere pollution. Deforestation has a negative impact on the environment and contributes to global warming. These negative changes have an impact on the natural hydrological cycle. The discharge of industrial waste, toxic chemicals, pesticides, radioactive substances, and plastics into bodies of water has a negative impact on the freshwater system as well as aquatic plants and animals.
The combustion of fossil fuels is the primary source of harmful greenhouse gas emissions such as carbon dioxide, sulphur dioxide, and nitrogen oxides. Acid rain is caused by these gases. When this water collects in the hydrosphere, it becomes acidified, which has become a major issue around the world. Most fish cannot survive in acidified water, and their population has gradually declined.
As the population expands, so will the need for water. However, our lakes, rivers, freshwater ponds, and wells are dwindling. The scarcity of fresh water will become a major issue in the coming years. It is now difficult to sustain the hydrosphere due to rising temperatures.
- Over time, the amount of water on the Earth’s surface remains constant. This means that the amount of water on Earth today is the same as it was when dinosaurs roamed the planet.
- Permanent snow contains 68.7% of the world’s freshwater.
- The oceans contain approximately 71% of the water on Earth.
- The total amount of water on the planet is approximately 333 million cubic miles (1,386 million cubic kilometres).
- This topic holds importance for the UPSC exam when it comes to geography and an aspirant must be well versed with Hydrosphere, its components and the Hydrological cycle.
Q) What is Hydrosphere?
Ans. It is the component of the earth that contains all of the liquid water on the planet. It includes water storage areas such as oceans, seas, lakes, ponds, rivers, and streams.
Q) What are the components of a Hydrosphere?
Ans. Mainly there are four components of the Hydrosphere – Oceans, Freshwater, Glacial water, and Atmospheric water vapour.
Q) What are the stages of the Hydrological cycle?
Ans. There are three major stages of the Hydrological cycle Evaporation, Condensation, and Precipitation.
Q) How much percentage of Water do Oceans contain?
Ans. The oceans contain approximately 71% of the water on Earth.
Q) What is the Hydrological cycle?
Ans. The hydrosphere of the earth contains water in the forms of gas, liquid, and solid. The hydrological cycle is the name for this pattern of water movement.
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