land resources (evs)

LAND RESOUCES

Non-renewable resource

Essential for functioning

Supports all living beings

But is depleting day by day

LAND AS A RESOURCE

What is soil?◦ The weathered surface of earth’s crust which is

associated with living organism and the products of their decomposition.

Pedogenesis - process of soil formation The main constituent of land

SOIL

The process of breaking up of rocks into smaller particles is called weathering.

Three types of weathering:◦ Physical◦ Climate◦ Biological

WEATHERING

LAYERS OF SOIL

Red soil◦ Largest soil group◦ Rich in iron, mangnesium◦ Found in maximum parts of India.

Black soil(regur)◦ Large clay factor,without gravel◦ Contains high moisture and extrimely sticky◦ Mostly seen in central India

TYPES OF SOILS IN INDIA

Laterite soil and lateretic soil◦ Lack in fertility and low value for production◦ Contains potash,nitrogen and phosphates

Alkaline soil(reh,usar)◦ Found in drier areas◦ Mostly not suitable for cultivation◦ Imperious , thus slow drainage

Mountain and forest soils of himalayan region◦ Found in depressions of valley and slopes◦ Provides heavy growth to plants

LAND DEGRADATION

•Land degradation refers to a decline in the overall quality of soil, water or vegetation condition commonly caused by human activities.

Deforestation by fire clearence Wind erosion Water erosion Pollution including industrial wastes Poor farming practises Livestocks including overgrazing

CAUSES

Loss of quality of soil and decline in vegetation

salinity/ brackishness of land Drought Soil erosion shortage of fuelwood and building materials

in many areas.

EFFECTS

Landslides

•A landslide (or landslip) is a geological phenomenon which includes a wide range of ground movement.

•Such as downward sliding, falling, or flowing of masses of soil, rock, and debris.

Loss or absence of soil nutrients (e.g. after a wildfire)

Erosion of the toe of a slope by rivers or ocean waves

Weakening of a slope through saturation by snowmelt, glaciers melting, or heavy rains

Earthquakes

Volcanic Eruptions

Causes Of Landslides

Vibrations from Machinery or Traffic

Blast’s

Construction

Forestry Activities

Causes Of Landslides (By Human Beings)

Falls◦ Soil or Rock masses freefall from Air.◦ Generally result from undercutting by erosion.

Slides◦ Failure among one or more narrow planes.◦ Types Of Slides :

Slumps, Glide, Rockslide

Types Of Landslides

Flow◦ Caused by Internal Displacement in Soil.◦ Types Of Flow :

Earthflow Rockslide

The process by which rocks fragments and soil are detached from the original site, transported and then eventually deposited at some new locality is termed as soil erosion.

SOIL EROSION

MEANING

Normal and Geological Soil Erosion(Erosion done naturally)

Accelerated soil erosion(Loss of Soil by Man’s Activity)

KINDS OF SOIL EROSION

Water Erosion◦ Sheet erosion◦ Rill erosion◦ Gully erosion

Wind erosion◦ Saltation◦ Suspension◦ Surface creep

AGENTS OF SOIL EROSION

Landslides or slip erosion Biotic agencies cause soil erosion

◦ Overgrazing◦ Deforestation

DESERTIFICATION

The transformation of aerable or habitable land to desert,as by a change in climate or destructive land use

Viewed as both a process and the resulting condition

Is a global problem Leads to abandoned,desert like landscapes

WHAT IS IT?

Overgrazing Deforestation Overcultivation Inappropriate irrigation Drought Climate change

CAUSES

Reduced biological productivity Biodiversity loss Loss of food security Increase in soil erosion Decreasing water availablity Loss of bio-diversity

CONSEQUENCES

Afforestation Water conservation Live-stock management Wise-agriculture methods

COUNTERING DESERTIFICATION