3. Hydrological cycle Insolation, or energy (in the form of heat and light) from the sun, provides the energy necessary to cause evaporation from all wet surfaces including oceans, rivers, lakes, soil and the leaves of plants. Water vapor is further released as transpiration from vegetation and from humans and other animals. Aquifer drawdown or overdrafting and the pumping of fossil water increases the total amount of water in the hydrospherethat is subject to transpiration and evaporation thereby causing accretion in water vapour and cloud cover which are the primary absorbers of infrared radiation in the earth's atmosphere. Adding water to the system has a forcing effect on the whole earth system, an accurate estimate of which hydrogeological fact is yet to be quantified.
4. WHAT IS HYDROSPHERE?The hydrosphere is the liquid water component of the Earth. It includes the oceans, seas, lakes, ponds, rivers and streams. The hydrosphere covers about 70% of the surface of the Earth and is the home for many plants and animals.
5. HYDROSPHERE OF EARTH All the water in its various forms, present in all thecomponents of Earth’s environment together constitutes the hydrosphere. Most of the water is present as liquid water on the Earth’s surface and some liquid water is present underground. Apart of total water is present as snow or ice on the Earth’s surface while a substantial part of water in Earth’s environment is also present as water vapor in the atmosphere. General features of various parts of the Earth’s hydrosphere are as given below: 1. Oceans: Major part of water is present in the oceans of the Earth. Average depth of oceans is about 3.7 kilometers and about 1300 million cubic kilometers water is present in oceans. 2. Ice sheets: Substantial quantity of water, about 24 million cubic kilometers, is present as solid in the ice sheets of Earth. About 90% of the volume of such water is found in Antarctica. 3. Groundwater: About 24 million cubic kilometer water is present under the ground surface at depths of upto two kilometers. 4. Lakes and rivers: On the land surface, approximately 0.18 million cubic kilometer water is present in lakes while about 0.002 million cubic kilometer water is found in rivers. 5. Atmospheric moisture: The amount of water present as water vapor in the atmosphere is about 0.013 million cubic kilometer. 6. Biological water: In addition to above categories, about 0.001 million cubic kilometer water is contained in the bodies of living organisms
6. Importance of Hydrosphere Most important feature of global environment of Earth is the hydrological cycle which determines the distribution of water on Earth’s surface and in the atmosphere. The water is evaporated from surface of water bodies like oceans, lakes, rivers etc. as water vapor into atmosphere. It is also absorbed by plants from soil and lost as vapor to atmosphere through transpiration. The water vapor condenses in the atmosphere to form precipitation and thus water is returned from the atmosphere to the surface of Earth. Cyclic movement of water in different components of the global environment is termed hydrological cycle.
8. What is Water Pollution? Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds. Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.
9. Causes and Effect of Water pollution Water pollution has been seriously affecting the life of humans, plants as well as animals. The eco-system of rivers, streams, lakes, seas and oceans is also getting deteriorated due to the contamination of water, through various sources. This condition also leads to the outbreak of numerous diseases, majority of them being lethal and contagious. However, before going about finding a solution to the problem, we need to look into its underlying causes. In the following lines, we have provided information on the causes and harmful effects of water pollution. Go through them and then decide on your course of action.
10. Sources of Water Pollution Dumping of industrial wastes, containing heavy metals, harmful chemicals, by-products, organic toxins and oils, into the nearby source of water is one of the visible causes of water pollution. Another cause for the contamination of water is the improper disposal of human and animal wastes. Effluents from factories, refineries, injection wells and sewage treatment plants are dumped into urban water supplies, leading to water pollution. A number of pollutants, both harmful and poisonous, enter the groundwater systems through rain water. The residue of agricultural practices, including fertilizers and pesticides, are some of the major sources of water pollution. Untreated pollutants are drained into the nearest water body, such as stream, lake or harbor, causing water pollution. Another major source of water pollution comprises of organic farm wastes. When farm land, treated with pesticides and fertilizers, is irrigated, the excess nitrogen and poisons get mixed into the water supply, thereby contaminating it. Pathogens, sediments and chemical pollutants are other sources of water pollution. The corporeal wastes produced by humans and farmed organisms pollute rivers, lakes, oceans and other surface waters.
11. Harmful Effect of Water Pollution Harmful Effects Of Water Pollution A number of waterborne diseases are produced by the pathogens present in polluted water, affecting humans and animals alike. Pollution affects the chemistry of water. The pollutants, including toxic chemicals, can alter the acidity, conductivity and temperature of water. Polluted municipal water supplies are found to pose a threat to the health of people using them. As per the records, about 14000 people perish or incur various communicable diseases due to the consumption of contaminated drinking water. The concentration of bacteria and viruses in polluted water causes increase in solids suspended in the water body, which, in turn, leads to health problems. Marine life becomes deteriorated due to water pollution. Lethal killing of fish and aquatic plants in rivers, oceans and seas is an aftereffect of water contamination only. Diseases affecting the heart, poor circulation of blood and the nervous system and ailments like skin lesion, cholera and diarrhea are often linked to the harmful effects of water pollution. Carcinogenic pollutants found in polluted water might cause cancer. Alteration in the chromosomal makeup of the future generation is foreseen, as a result of water pollution. Discharges from power stations reduce the availability of oxygen in the water body, in which they are dumped. The flora and fauna of rivers, sea and oceans is adversely affected by water pollution.
12. Water Pollution in The Philippines A century ago the Pasig River in the Philippines was a place of beauty. The water was clean and teeming with life. It provided food and an income to Manila’s fishermen and was the transportation artery of the capital. Today the river is a place to avoid. The river's banks are covered with squatters’ huts. The water is pitch black and choked with rubbish. The Philippine Government has passed a Clean Air Act and Clean Water Act, but there is no budget available to implement either. Peter Coppen reports from Manila.
14. WATER POLLUTION SOLUTIONS Cities with sanitary sewer overflows or combined sewer overflows employ one or more engineering approaches to reduce discharges of untreated sewage, including: utilizing a green infrastructure approach to improve storm water management capacity throughout the system, and reduce the hydraulic overloading of the treatment plant repair and replacement of leaking and malfunctioning equipment[15] increasing overall hydraulic capacity of the sewage collection system (often a very expensive option). A household or business not served by a municipal treatment plant may have an individual septic tank, which treats the wastewater on site and discharges into the soil. Alternatively, domestic wastewater may be sent to a nearby privately owned treatment system (e.g. in a rural community).
15. Water pollution Prevention Tips Do not keep the water running when you're brushing your teeth, washing your hands, washing the dishes. Taking small steps like these are an important way of preventing water wastage that is fast depleting due to water pollution. Make sure that you dispose off other forms of wastes like tissue papers and the odd trash bits by putting them in trash bins rather than flushing them down the drain. Do not allow household wastes like your pet waste or other items like petrol, motor oil, paint and other such items to be discarded in trash or be thrown into the sewer. These will seep down to the water source and pollute it in the worst possible way. Use native plants instead of hybrid ones as those require a lot of pesticides and chemicals for their protection. When it rains, these chemicals seep into the ground water, thus polluting it. Make sure that products which can be recycled are given off to recycling units instead of disposing them off at random. This will ensure that pollution is prevented. Set up a compost unit so that all the household waste can be converted into manure or compost rather than being disposed off in the wrong manner and leading to more pollution. There have been many water pollution prevention acts that have been set up by the governments of the world. But these are not enough for permanent water pollution solutions. Each of us need to take up the responsibility and do something at an everyday level. It is only then that we can hope to survive in a world as we hoped and dreamed of.
