Introduction: Natural resources are derived from the environment. Some of them are essential for our survival while most are used for satisfying our wants. Natural resources may be further classified in different ways.
Natural resources are materials and components (something that can be used) that can be found within the environment. Every man-made product is composed of natural resources (at its fundamental level). A natural resource may exist as a separate entity such as fresh water, and air, as well as a living organism such as a fish, or it may exist in an alternate form which must be processed to obtain the resource such as metal ores, oil, and most forms of energy.
There is much debate worldwide over natural resource allocations, this is partly due to increasing scarcity (depletion of resources) but also because the exportation of natural resources is the basis for many economies (particularly for developed nations such as Australia).
Some Natural resources can be found everywhere such as sunlight and air, when it is so the resource is known as an ubiquitous (existing or being everywhere) resource. However most resources are not ubiquitous. They only occur in small sporadic areas; these resources are referred to as localized resources. There are very few resources that are considered inexhaustible (will not run out in foreseeable future) – these are solar radiation, geothermal energy, and air (though access to clean air may not be). The vast majority of resources are however exhaustible, which means they have a finite quantity, and can be depleted if managed improperly. The natural resources are materials, which living organisms can take from nature for sustaining their life or any components of the natural environment that can be utilized by man to promote his welfare is considered to be natural resources.
Uses of land resources:
- Land nurtures the plants and animals that provide our food and shelter.
- Land is used as watershed or reservoir
- Land acts as a dust bin for most of the wastes, created by the modern society.
- Land is used for construction of buildings, industries.
- Land provide, food, wood, minerals, etc., for us
Types of soil erosion:
- Gradual removal of top soil by the natural process.
- The rate of erosion is slower.
Causes of soil erosion:
a. Water: Affects soil erosion in the form of rain, run-off, rapid flow, wave action.
b. Rill erosion:when there is rainfall and rapidly running water produces finger-shaped grooves or rills over the area, it is called rill erosion.
c. Gully erosion:When the rainfall is very heavy, deeper cavities or gullies are formed, which may be U or V shaped.
d. Slip erosion:This occurs due to heavy rainfall on slopes of hills and mountains.
Stream bank erosion: During the rainy season, when fast running streams take a turn in some other direction, they cut the soil and make caves in the bank.
(ii)Wind: Wind is the important climatic agent, who carry away the fine particles of soil and creates soil erosion.
a. Saltation: This occurs under the influence of direct pressure of stormy wind and the soil particles of 1-1.5 mm diameter move up in vertical direction.
b. Suspension:Here fine soil particles (less than 1mm diameter) which are suspended on the air are kicked up and taken away to distant places.
c. Surface creep:Here the large particles (5-10 mm diameter) creep over the soil surface along with wind.
- Overgrazing, mining and deforestation are the major biotic agents, cause soil erosion.
- Deforestation without reforestation, overgrazing by cattle, surface mining without land reclamation, irrigation techniques that lead to salt build- up, water logged soil, make the top soil vulnerable to erosion.
- 35% of world soil erosion is due to overgrazing.
- 30% of world soil erosion is due to deforestation.
(iv) Landslides: Causes soil erosion.
(v)Cons Control of soil erosion (or) soil conservation practice:
- In tradition method, the land is ploughed and soil is broken up and leveled to make a planting surface.
- This disturbs the soil and makes it susceptible to erosion
- However, no-till-farming causes minimum disturbance to the top soil
- Here the tilling machines make slits in the unplugged soil and inject seeds, fertilizers and water in the slit. So the seed germinates and the crop grows.