please send me the Chapter Our environment class 6 basic notes
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Sources of Water
Oceans, seas, lakes, rivers, ponds, rainwater and ground water are the sources of water.
Rain Water: Rainwater is the purest form of water. It collects on the earth in the form of surface water and underground water.
Surface Water: Water present on the surface of the earth in the form of oceans, seas, rivers, lakes, ponds and streams is called surface water. Ocean contains almost 97% of water present on the earth. But it is saline therefore it is unfit for drinking.
Underground Water: Some of the rainwater seeps through the soil and gathers in the non-porous rocks below. This water is known as underground water.
Conservation of Water
As we have studied earlier water is very important for us. So we must conserve water whenever it is possible. Some ways of water conservation are:
Turn off the water tap immediately after use.
Reuse water when it is discharged from various processes.
Check the working of your water equipment on regular basis.
Harvest rainwater.
Air
The earth's atmosphere (or air) is a layer of gases surrounding the planet earth that is retained by the earth's gravity. Dry air contains roughly (by volume) 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide and trace amounts of other gases.
Air also contains a variable amount of water vapor, on an average around 1%. The atmosphere protects life on earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect) and reducing extreme temperature between day and night.
Composition of Gases in Earth's Atmosphere
Layers of Atmosphere
There are five layers of atmosphere and these are troposphere, stratosphere, mesosphere, thermosphere and exosphere. Troposphere is the first layer of the atmosphere whereas exosphere is the uppermost. Stratosphere contains the ozone layer which protects us from the ultra-violet rays of sun.
Garbage
Garbage may refer to the waste, an unwanted or undesired material or substance
Types of Waste
There are two types of garbage: biodegradable and non-biodegradable
Biodegradable: The waste that can be decomposed by the microorganisms is called biodegradable waste. Biodegradable waste typically originating from plant or animal sources. For example, fruit and vegetable peels, leaves, papers, cow dung, wood, etc.
Non-biodegradable: The waste that cannot be decomposed by the microorganisms is called non-biodegradable waste. For example, plastics, glass, metals, etc
Disposal of Waste
There are different methods of disposal of waste:
Composting: By this method biodegradable waste is converted into manure which is used for agricultural purposes. Biodegradable waste is dumped in a pit. When the pit gets filled, some buckets of water are added to it. The pit is covered by a paste of soil and left for about three months. The microorganisms present in the soil decomposes the waste into useful manure
Vermicomposting: In this method biodegradable waste is converted into manure by redworms. The compost made by redworms is of high quality and known as vermicompost.
Recycling: In this method papers, some plastics, glasses and metal objects are separated from garbage and sent them to the respective industries for processing. Thus fresh papers, plastics, glasses and metals are obtained for reuse.
Reuse: This is the way of reusing papers, plastics, glasses and metal objects in the possible ways. For example, a damaged plastic bucket can be used as a pot for growing a flower plant. So if we use these non-biodegradable waste for other useful purposes, we can reduce a great amount of garbage produced by us and this will help us in keeping the environment clean.
Reduce: This is the best way for disposal of waste. It involves reducing the amount of waste we produce. If there is less waste, then there is less to recycle or reuse.
Organic waste which decomposes due to biological action is called biodegradable waste. ... do not decompose and are called non-bio degradable. • Waste management is necessary to protect the environment, prevent the spread of communicable diseases and obtain useful recyclable materials.