WEATHERING

WEATHERING

MADE BY- SAKSHI,APURAVA,DIVYA.IDEGRADATIONDegradation is the process by which rock materials from the earths surface are removed resulting in the general lowering of the land surface. These materials are then deposited elsewhere in depressions such as valleys, lakes, and sea beds.AGGRADATIONAggradation is the process by which depressions fill up and the level of the surface rises . Together ,these two process- degradation and aggradation- are termed as gradation . Gradation helps in levelling the land surface.WHAT IS WEATHERINGWeathering is the process by which rocks on the land surface breakdown or crumble because of the action of the elements of the weather such as rain, frost, and temperature changes . This process involves physical as well as chemical action . Erosion follows the process of weathering. Erosion is the process by which the weathered materials are transported elsewhere by agents such as running water, moving ice, waves, and winds.

FACTORS AFFECTING WEATHERINGThese are various factors influence the breakdown of rocks into fragments. These are local climate, mineral composition, amount of exposed or bare rock surface, and human activities.

TYPES OF WEATHERINGThere are mainly three types of weathering :

Physical weathering

Chemical weathering

Biological weatheringPHYSICAL WEATHERINGIn this type of weathering, rocks break up without any change in their chemical composition . These is called physical weathering and it can be happen in the many ways:

Granular disintegration

Exfoliation

Frost action

CHEMICAL WEATHERINGChemical weathering involves changes in the chemical composition of rocks, which result in their breaking up into smaller fragments . Chemical weathering can take place in many ways:

Oxidation

Carbonation

Hydration

Solution

BIOLOGICAL WEATHERINGSome rocks are also weathered by the action of plants, animals , and human beings . This type of weathering may be both physical as well as chemical.

Roots of plant growing in the cracks and joints widen the gaps. The often rocks break up. Besides, the water enters the cracks and may cause chemical weathering and frost action.

Mining, quarrying, deforestation, tunnelling, road construction, and farming are example of human activities that result in or contribute to the weathering of rocks.

SOILPhysical, chemical, and biological processes are involved in soil formation . It is one of the most important resources as human beings depend on it, both directly and indirectly, for their basic needs of food , shelter, and clothing. It takes thousands of years for even a thin layer of soil to form.SOIL EROSIONSoil erosion refers to the washing away or the removal of the layer of soil by the various agents like running water and wind. Sheet erosion and gully erosion are the two most common ways by which soil gets eroded. When there is heavy rainfall , the top layer of soil over large areas gets washed away . This is known as sheet erosion . When rainwater in a region flows down the slopes making deep and narrow furrows, it is called gully erosion.

SOIL CONSERVATIONThe protection of soil against erosion and exhaustion is called soil erosion . We can reduce the rate of erosion, if not prevent it completely, by planting more trees, shrub, and grass on hill slopes and uncultivated land. There are some ways to conserve soil:

Controlled grazing of cattle

Terracing of hill slopes

Construction of mud walls

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