الموضوع: Importance of Water

importance, water

Importance of Water
Our Earth seems to be unique among the other known celestial bodies. It has water, which covers three-fourths of its surface and constitutes 60-70 wt % of the living world. Water regenerates and is redistributed through evaporation, making it seem endlessly renewable. So why worry?behind text Children playing in Big Wheeling Creek. Photo: Courtesy of Karen Emmerth
Actually, only 1% of the world's water is usable to us. About 97% is salty sea water, and 2% is frozen in glaciers and polar ice caps. Thus that 1% of the world's water supply is a precious commodity necessary for our survival. Dehydration (lack of water) will kill us faster than starvation (lack of food). Since the plants and animals we eat also depend on water, lack of it could cause both dehydration and starvation. The scenario gets worse. Water that looks drinkable can contain harmful elements, which could cause illness and death if ingested.Water is necessary for the survival of most living things. In fact, dehydration--the lack of water--will kill an organism faster than starvation--the lack of food. Since the plants and animals that many humans and other animals eat also depend upon water, a lack of it could lead to starvation as well as dehydration. In addition to sustaining life, clean freshwater is needed by humans for personal hygiene, irrigation, industry, and recreation. Humans bathe in it, brush their teeth with it, use it to make crops grow and to cool industrial reactors, and swim, boat, and fish in it.
With all of the demands humans place on the hydrosphere, as well as climate changes which have led to droughts, the amount of available freshwater is decreasing. In addition, much of the available freshwater is being contaminated with harmful elements such as sulfuric acid, fertilizer, and gasoline. This happens as freshwater circulates through the hydrologic cycle. As precipitation passes through the atmosphere and flows over roads, agricultural fields, and other human-made objects, it picks up contaminants that often make it unusable. In a sense, precipitation "washes" the dirt and grime (contaminants) from the air and Earth's surfaces, just like the water washes the dirt off of you when you bathe. These contaminants are then carried to the streams, rivers, and eventually into the groundwater, lakes, and oceans of the world. Water quality may also be affected by natural causes such as volcanic eruptions.
The importance of clean water, coupled with its scarcity due to over-use, climate, and pollution, has resulted in increased concerns about water quality and quantity. These concerns have led to war between nations such as Namibia and Botswana. The concerns have even influenced US legislation

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Importance of Water