Soil Erosion

Soil Erosion•The loss and displacement of the earth’s fertile topsoil.•One of the most critical environmental problems in the world today.

Soil Erosion (Factors)

•Physical phenomena•Human intervention

Physical Phenomena•Rainfall

depending on its intensity, duration and distribution•Wind

specially strong gales which easily blow dry powdery soil and slope of the land which facilitates the soil run-off.

Human Intervention

•Deforestation•Overgrazing•Over cropping

Effects of soil erosion•Deterioration of agricultural land•Increase of flood occurrence•Reduced water supply•Siltation of reservoirs, canals and rivers.

Effects of soil erosion

•Destruction of buildings, roads and public works.•Depletion of wild life and other natural resources.

Activities of man contributing to soil erosions and disruption of the earth’s landscape

AGRICULTURAL DISRUPTION• LOGGING

2 FUNDAMENTAL WAYS 1.Selective cutting

loggers harvest only those mature trees that produce the most valuable timber and they leave the rest of the forest untouched

AGRICULTURAL DISRUPTION

2. Clear cuttingall the trees in an area

are cut. Small logs are used to manufacture paper, and large logs ate sown into boards.

AGRICULTURAL DISRUPTION

•FARMINGas the population

increases, there is no longer enough land to leave croplands fallow until the full, natural fertility can be established.

AGRICULTURAL DISRUPTION

•CATTLE RANCHINGIt is threatening

rainforest systems. Forest lands ate cleared yearly to be converted to cattle ranching operations which, in turn, destroy the soil.

AGRICULTURAL DISRUPTION

•GATHERING WOOD FUEL•HYDROELECTRIC DEVELOPMENT•URBANIZATION

DISRUPTION OF THE LANDSCAPE

•SURFACE MININGtypes of environmental

impact of mining1. Direct impact2. Indirect impact

DISRUPTION OF THE LANDSCAPE

•HIGHWAY CONSTRUCTION•STREAM CHANNELIZATION•JETTIES•To assure boatmen calm water for docking, rock barriers ate sometimes constructed offshore.

CHEMICAL FERTILIZATION

•Is the method or process of supplying/applying chemical compound as a source of one or more of the essential plant food elements.

CHEMICAL FERTILIZATION

•Is the method or process of supplying/applying chemical compound as a source of one or more of the essential plant food elements.

GREEN REVOLUTION

•The introduction of high-yield green varieties on a commercial scale was developed in the middle and late 1960’s.

USE OF PESTICIDES

•A re a pest-killing agent (Latin word CIDE means to cut or kill). Defined by the Fertilizer and Pesticides Authority (FPA).