Water Bodies and Pollution - Class VI

The hydrosphere encompasses all water found on, under, and over the surface of the earth, including oceans, lakes, and rivers.

The continental shelf is the shallow, submerged extension of the continent that extends from the shoreline to the shelf break.

With 33.7% salinity, the Dead Sea is one of the world's saltiest bodies of water. The Dead Sea is landlocked and in the lowest valley on earth. All the minerals of the surrounding countryside get washed into one pool, which in turn gets baked by the sun. This concentrates the salts so much that the Dead Sea is 10 times as salty as the ocean.

Rivers are the primary source of freshwater for human use and ecosystems, as they collect runoff from precipitation.

Deep sea sediments are largely composed of the remains of microscopic organisms (like foraminifera and diatoms) that settle on the ocean floor.

Approximately 71% of the Earth's surface is covered by water, which constitutes the hydrosphere.

The most abundant dissolved ions in seawater are sodium, chloride, magnesium, sulfate and calcium. Its osmolarity is about 1000 mOsm/l.

Wastewater effluent treatment is important way to control pollutants reaching in water bodies.

• Dissolved oxygen is the amount of free oxygen present in water which is not bound to any other element.
  
• If there is an increase in pollution rates dissolved oxygen rate drops drastically affecting aquatic life.
  

Acid rains: when the concentrations of oxides of nitrogen and sulphur increases in the air, rain water gets mixed up with these oxides to form acid rains.

Among the given options all are apt for the effects of acid rain except that it causes damage to the septic system.

It cannot cause damage to the septic system because most of the septic systems are underground and polluting such system with acids do not cause any adverse reaction to the environment.

Accelerated chemical weathering of building materials, damage to forests and crops, damage to aquatic organisms are the immediate effects of acid rains

Eutrophication is the enrichment of water bodies with nutrients, leading to excessive plant growth and subsequent oxygen depletion as the plants decay.

DDT is a classic example of a persistent organic pollutant that accumulates in fatty tissues and increases in concentration up the food chain.

A virus is a simple submicroscopic parasite of plants, animals, and bacteria in well water that can cause disease. It consists essentially of a core of RNA or DNA surrounded by a protein coat. Viruses are not living organisms and are unable to replicate without a host cell. Some viral infections often associated with drinking or bathing in contaminated water include:

Gastroeneritus – Causes diarrhea, nausea, vomiting, fever, and abdominal pain.

Cryptosporidiosis – Causes flu-like symptoms, diarrhea, weight loss, bloating, and nausea.

Water pollution can be defined as alteration in physical, chemical or biological characteristics of water, making it unsuitable for designated best use in its natural state.  

World Health Organization (WHO) has defined water pollution as inclusion of any foreign material either from natural or other sources into a water body, thereby changing the natural qualities of water and making it unusable for its intended purpose.

Biomagnification refers to the increase in concentration of a substance, such as a toxic chemical, as it moves up the trophic levels of a food chain.

Fluoride in drinking water at low concentrations helps prevent tooth decay, but excessive levels can lead to fluorosis, which affects bones and teeth.

Persistent Organic Pollutants (POPs) are toxic chemicals that resist degradation and can travel long distances, often contaminating groundwater and soil.

Malaria is a vector-borne disease transmitted by mosquitoes, not by drinking contaminated water, unlike cholera, jaundice, and diarrhoea.

Industrial pollution contaminates many sources of drinking water, releases unwanted toxins into the air and reduces the quality of soil all over the world. Major environmental disasters have been caused due to industrial mishaps, which have yet to be brought under control. From the given options, electronics industry does not spread water pollution.

Municipal waste refers to the waste generated by households and businesses in a community, which includes a mix of organic and inorganic materials.

The Ganga Action Plan was initiated by the Government of India in 1986 to reduce the pollution load on the river Ganga.

Biomagnification is specifically defined as the increase in concentration of toxic substances as they pass through successive trophic levels in a food chain.

While many microorganisms are harmless, pathogenic microorganisms are the specific agents that cause diseases in humans when present in water.

Dhebar lake (also known as Jaisamand lake) is Asia's second-largest artificial lake. It is located in the Udaipur District of Rajasthan state in western India. It has an area of 87 km when full, and was created in the 17th century when Rana Jai Singh of Udaipur built a marble dam across the Gomati River.

The Gadsisar Lake is one of the most famous tourist places in Jaisalmer which was built by Raja Rawal Jaisal, the first ruler of Jaisalmer. In the later years Maharaja Garisisar Singh rebuilt and revamped the lake. This historic lake is located towards the south of Jaisalmer city. The bank of the Gadsisar lake is surrounded by artistically carved Chattris, Temples, Shrines, and Ghats. Its charm lies in the fact that it was the only source of water for the Jaisalmer city in the olden days.

With a growing population comes a growing demand for water from the three main sectors of agriculture, around 70 percent, industry, around 22 percent and domestic use, around 8 percent. This increase in demand will cause a shortfall of almost 2000 megaliters of water by 2030.

Dryland communities have also developed deep knowledge of water and its elements. From the name of a particular system,(eg. a nadi) people knew how the water is collected, catchment prepared, embankment constructed, etc. Diverse systems to suit local ecology, geology, climate: nadi, talab, johad, bandha, etc. So many kinds of wells: Dugwells: kua owned by individuals; kohars community wells. Step wells: Baolis for drinking; constructed for philanthropic purposes; jhalaras not used for drinking. Different in architecture, Sagar ka kua : never run dry, Seer ka kua: underground channel opening into a well..

In many Indian languages, 'Sar' or 'Sarovar' refers to a lake or a water body.

There are reserves of a variety of natural resources in seawater, at the bottom of the sea and beneath the seabed, too. These resources available from seas and oceans are called marine resources.

The Pacific is the largest, the Atlantic is the second largest, and the Indian Ocean is the third largest ocean in the world.

The Indian Ocean is landlocked to the north and subject to seasonally reversing monsoonal winds, causing ocean currents to change direction regularly rather than flow in a permanent steady pattern.

Its average depth is about 3,688 meters (12,100 ft), and its maximum depth is 10,994 meters (6.831 mi) at the Mariana Trench. Nearly half of the world's marine waters are over 3,000 meters (9,800 ft) deep. The vast expanses of deep ocean (anything below 200 meters or 660 feet) cover about 66% of Earth's surface.

Ionian Sea, Latin Mare Ionium, Italian Mare Ionio, part of the Mediterranean Sea, lying between Albania (northeast), Greece (east), Sicily (southwest), and Italy (west and northwest). Though considered by ancient authors to be part of the Adriatic Sea, the Ionian Sea is now seen as a separate body of water.

The upper flow leaves the Black Sea and carries surface water out of it. Meanwhile a bottom flow carries salt water, about 35‰ from the Mediterranean to the Black Sea. The salty water mixes with the waters of the basin proper and that results in a comparatively low salinity at the surface, about 17%.

The Bay of Cambay (or Gulf of Khambhat) is an inlet of the Arabian Sea on the west coast of India.

The prefix 'iso' is a greek word meaning equal, so an isoline must be a line joining equal points. For example, a line drawn on a map to join up all the places that are the same height above sea level is called a contour.