Syllabus LAND RESOURCES

Syllabus -LAND RESOURCES Land as a resource  Land is a finite and valuable resource upon which we depend for the basic amenities of life  Soil is classified as a renewable resource  The rate of regeneration of soil is very slow, about 200-1000 years are needed for the formation of 1” of soil, depending on the climate and soil type Land degradation  With increasing population growth the demand for arable land for producing food, fiber and fuel wood are also increasing  more and more pressure on the limited land resource; degraded due to over exploitation  Soil degradation is a real cause of alarm because soil formation is an extremely slow process  Soil erosion, water-logging, salinization and contamination of the soil with the various industrial wastes … cause land degradation Soil Erosion  Soil erosion means wearing away of the soil; defined as movement of soil components, especially surface litter and top soil from one place to another  Soil erosion results in loss of fertility because it is the top soil layer that is fertile Types  Normal erosion or geologic erosion gradual removal of top soil by natural processes which bring an equilibrium between physical, biological and hydrological activities and maintain a natural balance between erosion and renewal  Accelerated erosion caused by anthropogenic activities; the rate of erosion is much faster than the rate of formation of soil; Overgrazing, deforestation, mining  accelerated erosion Agents causing soil erosion  Climatic Agents Water and wind are the climatic agents of the soil erosion Water effects soil erosion in the form of torrential rains, rapid flow of water along slopes, run-off, wave action and melting and movement of snow Wind affects soil erosion in the form of saltation (vertical movement of soil under the influence of direct pressure of stormy winds), suspension and surface creep  Biotic Agents Excessive grazing, mining and deforestation are the major biotic agents responsible for soil erosion Due to these processes the top soil is disturbed or rendered devoid of vegetal cover Soil Conservation Practices Conservational till farming Contour farming Terracing Strip Cropping Alley Cropping Conservation till farming  Special tillers are used to break up and loosen the subsurface soil without turning up the top soil  The tilling machine make slits in the un-ploughed soil and injects seeds, fertilizers, herbicides and a little water in the slit, so that the seed germinates and the crop grows Contour Farming  Growing of crops in rows across, rather than up and down is called as contour farming  Each row planted horizontally along the slope of the land acts as a small dam to help hold soil and slow down loss of soil through run-off water Terracing Strip cropping Shelter Belt Land Slides  Various anthropogenic activities like hydro-electric projects, large dams, reservoirs, construction of roads and railway lines, construction of buildings, mining … are responsible for clearance of large forested areas  During the construction of roads, mining activities etc., huge portions of fragile mountainous areas are cut or destroyed by dynamite and thrown into adjacent valleys and streams These activities weaken the already fragile mountain slopes and lead to land slides  They also increase the turbidity of various nearby streams thereby reducing their productivity Desertification  Desertification is a process whereby the productive potential of a rid and semi-arid land falls by 10% or more  Moderate desertification – 10-25% drop  Severe desertification – 25-50% drop  Very Severe desertification – >50% drop  Desertification is characterized by devegetation and loss of vegetal cover, depletion of ground, salinization ans severe soil erosion Causes → Deforestation, Overgrazing, Mining… Resource Management Sustainable development • Sustainable development, meets the needs of the present without compromising the ability of future generations to meet their own needs • Environmental sustainability is based on following ideas: – – Earth’s resources are not present in infinite supply Live within limits that let renewable resources such as fresh water regenerate for future needs – Share the responsibility for environmental sustainability ASSIGNMENT • Equitable use of Resources for Sustainable Lifestyle [...]... their own needs • Environmental sustainability is based on following ideas: – – Earth’s resources are not present in infinite supply Live within limits that let renewable resources such as fresh water regenerate for future needs – Share the responsibility for environmental sustainability ASSIGNMENT • Equitable use of Resources for Sustainable Lifestyle ... adjacent valleys and streams These activities weaken the already fragile mountain slopes and lead to land slides  They also increase the turbidity of various nearby streams thereby reducing their productivity Desertification  Desertification is a process whereby the productive potential of a rid and semi-arid land falls by 10% or more  Moderate desertification – 10-25% drop  Severe desertification – 25-50%...Shelter Belt Land Slides  Various anthropogenic activities like hydro-electric projects, large dams, reservoirs, construction of roads and railway lines, construction of buildings, mining … are responsible for clearance ... type Land degradation  With increasing population growth the demand for arable land for producing food, fiber and fuel wood are also increasing  more and more pressure on the limited land resource;.. .Land as a resource  Land is a finite and valuable resource upon which we depend for the basic amenities of... horizontally along the slope of the land acts as a small dam to help hold soil and slow down loss of soil through run-off water Terracing Strip cropping Shelter Belt Land Slides  Various anthropogenic