(Written By Ayesha Salim): - A priceless natural resource is water. Water is a necessity for all living things to survive. Without water, life is unimaginable. Animals and plants alike need water to carry out their everyday metabolic processes. Water is necessary for plants to produce their nourishment during the photosynthesis process.

An individual uses, on average, 600 to 700 gallons per day. We all have the ability to go without food for extended periods of time, but we cannot even begin to comprehend living without water. Absent of water, even plants get dry and lose their leaves.

One of the natural resources that are present in a sufficient amount is water. It is a necessary component for life to exist on earth. It is frequently used for a wide range of activities, including drinking, washing, bathing, cleaning, cooking, irrigation, and other residential and commercial functions.

There are numerous water sources. On the surface of the Earth, water covers around 97% of the area. These are the top three water sources:

1. Rainwater
2. Waterbodies like springs and wells are considered to be groundwater.
3. Surface water is any water that is on the surface of another body of water, such as the sea, oceans, reservoirs, rivers, streams, ponds, lakes, and tanks.

 

Cycle of Water

The motion of water is constant. The four stages of the water cycle are typically followed by the process of water continuously moving from the earth's surface. The hydrological cycle is another name for the cycle that the sun controls in its whole.

Evaporation: In this phase, the heat from the sun warms the water in the seas and other water bodies, causing it to evaporate as vapours that rise to the sky and create clouds.

The clouds' water vapour condenses as it cools.

Precipitation: Precipitation is the release of cooled water vapour from clouds into droplets that fall as rain or snow back to the earth's surface.

Rainwater is gathered by evaporation and then flows back into the ocean through ponds, rivers, and wells.

The surface of the Earth is covered in water to a degree of 97%, as was already indicated. A safe percentage for drinking is only 2 to 3%. Two-thirds of the freshwater on Earth is frozen in glaciers, making up the remaining water, which is primarily inaccessible to humans and is made up of salt.

To prevent further waste from this renewable source and to save water for future needs, we all need to limit our current water usage.

 

Sources of freshwater resources in nature

 

Surface Water

A river, lake, or freshwater wetland all contain surface water. Surface water is produced from renewable by rainfall and naturally depleted by evaporation, evapotranspiration, groundwater recharge, and discharge to the oceans. Any surface water system's only natural input is precipitation from its watershed. Numerous other elements affect how much water is present in that system overall at any given time. These variables include the ability of lakes, wetlands, and man-made reservoirs to store water, as well as the transparency of the soil that lies beneath them, the characteristics of the terrain that contributes to runoff in the watersheds, the timing of precipitation, and regional evaporation rates. The amounts of water loss are also impacted by each of these elements.

 

Glacier-produced water

Surface water is regarded as including runoff from glaciers. The Himalayas, which are frequently referred to as "The Top of the World," is home to some of the largest and roughest high-altitude areas on the planet as well as the sector is a highly of glacier and tundra outside of the poles. From there, ten of Asia's greatest rivers flow, and they are essential to the livelihoods of much more than one billion people. There are additional complications because the temperature there is rising faster than the norm worldwide. Over the past ten years, the temperature in Nepal has increased by 0.6 degrees Celsius, whereas the Earth's temperature has increased globally by about 0.7 degrees Celsius.

 

The Groundwater

Water found in soil, rock, and rock formation fissures is known as groundwater. It is also found beneath the surface of the Earth. Groundwater makes up around 30% of the world's readily usable freshwater.

The water table is the depth at which rock cracks and voids, as well as soil pore spaces, are totally saturated with water.

By building and using extraction wells, groundwater is frequently extracted for agriculture, municipal, and industrial usage.

 

Downstream of a river

The total amount of water carried downstream during the length of a river frequently consists of both the apparent free water flow and a sizeable portion running under rocks and sediments known as the hyporheic zone, which lies underneath the stream and its floodplain. This invisible element of flow may dramatically enhance the visible flow for so many rivers in big valleys. Aquifer groundwater and surface water frequently interact dynamically at the hyporheic zone, swapping flow among aquifers and rivers that could be charged up or depleted. This is crucial in karst regions where subsurface rivers and potholes are prevalent.

 

Artificial water supplies that can be used

 

Reusing wastewater

The process of turning municipal wastewater (sewage) or industrial wastewater into water that can be reused for a number of reasons is known as water reclamation (also known as wastewater reuse, water reuse, or water recycling).

Urban reuse, agricultural reuse (irrigation), environmental reuse, industrial reuse, planned potable reuse, and de facto wastewater reuse are a few examples of reuse types (unplanned potable reuse).

Treatment of wastewater for reuse involves a number of technologies. These methods combined can ensure that treated water is hygienically safe, or pathogen-free, and that it complies with stringent treatment criteria. Some of the standard technologies are as follows: advanced oxidation, membrane bioreactor, ozonation, ultrafiltration, forward and reverse osmosis, and aerobic treatment.

 

Distilled water

Desalination is a method used to remove minerals from saltwater. Desalination more generally refers to the process of removing minerals and salts from a particular compound, such as soil, which is problematic for agriculture. Desalination is the process of turning saltwater, particularly seawater, into water that is appropriate for irrigation or human consumption.

Many seaborne ships and submarines employ desalination. The majority of current attention in desalination is concentrated on providing fresh water to human use in an economical manner. It is one of the few water supplies that are not dependent on rainfall, along with recycled wastewater.

 

Threats and challenges of water resources

 

Lack of water

When there aren't enough freshwater resources to satisfy the average water demand, there is a water shortage.

There are two types of water scarcity

Physical  water scarcity

Physical water shortage occurs when there isn't enough water available to satisfy all demands, including those of ecosystems. Physical water scarcity is a common problem in arid regions, such as Central and West Asia and North Africa.

 

Economic water scarcity

Economic water scarcity results from inadequate human capacity to meet the demand for water or from a lack of infrastructure investment or technology to take water from rivers, reservoirs, or other water sources.   Water scarcity affects most of Sub-Saharan Africa economically.

 

Water pollution

Water contamination is the tainting of bodies of water, frequently as a result of human influence, which has a detrimental impact on their uses. Aquifers, reservoirs, lakes, rivers, seas, and groundwater are all examples of bodies of water.

Wastewater discharge, industrial activities, agricultural practices, and urban runoff, including rainwater, are the four main causes of water contamination.

 

Conflict over water

A fight over the right to utilize water resources is referred to as a "water conflict" between nations, states, or other parties.

Territorial disputes, competition for resources, and competitive value are only a few of the reasons why there are water conflicts.

 

Changing weather

People's daily water security is impacted by climate change's water-related effects. The intensity, amplitude, and timescale of floods have changed, as have the severity and frequency of heavy precipitation. In some areas, there have also been increases in the frequency and severity of severe droughts. Groundwater storage has decreased, groundwater recharge has decreased, and water quality has gotten worse as a result of extreme events. Climate change can have a variety of effects on water resources. Freshwater availability overall in a given area is subject to change, for example because of dry periods or droughts. The impacts of climate change may also result in decreased water quality.