SOIL PROBLEMS
Erosion
Erosion is defined as the process which rock fragments and
sediments (products of weathering) are a carried along by such agents as
running water and wind.
When does erosion become
harmful? Only when it is extensive. This is brought about by several activities
of the people such as the following:
1. Shifting cultivation to kaingin system – burning the field after harvest leaving the soil bare and planting root crops on steep slopes.
2. Construction projects – e.g. roads, dams, reservoirs, irrigation and drainage projects, hydroelectric plants, resorts and other related facilities.
3. Mining – mining operations dig out and loosen rocks in the mountains, exposing them to further erosion.
4.
Over
gazing and burning of grassland – grass as soil cover reduces the rate of
run off. Uncontrolled grazing of animals removes the grass cover and packs and
soil more. What happens when the soil is tightly packed?
Effects of Soil Erosion
1. Deterioration of farmlands
2. Deterioration of forests
3. Occurrence of floods and droughts
4. Siltation of rivers and water reservoirs
5. Destruction of houses and infrastructure
Soil Erosion Control
A. Preventive type of soil erosion for slightly eroded areas
1.
forest fore prevention
2.
proper land use
3.
correct range and forest management
4.
proper road construction
5.
education of the people
B. Rehabilitation types
1.1 reforestation
1.2 afforestation
1.3 cover
cropping
1.4 crop
rotation
1.5 strip
cropping
2. Mechanical method
2.1 terracing
2.2 contouring
2.3 riprapping
2.4 construction of dikes along river banks
2.5 constructing farm ponds
Soiled Pollution
The addition of materials to the soiled that may be harmful to
people and other living things. Pesticides are the main source of soil
pollution in our country.
WATER PROBLEMS
It is estimated that the total amount of water in the universe
is a constant 1.5 billion cubic kilometres and that only 1/30 of this total
amount is fresh water. Of the total amount of water (fresh), only 1/3 is
available for domestic and industrial use. This is because most of the fresh
water sources are locked up in glaciers and ice caps in the worlds tallest
mountains, and the rest is too far underground or contains too much mineral to
be useful.
WATER POLLUTION
a. Domestic sewage
b. Industrial wastes
b1. Organic substances
b2. Inorganic substances – acids and toxic substances
c. Mine tailings – consist of silt, toxic metals, acids, bases and
inorganic salts.
d. Agricultural run off
d.1 fertilizer residues
d.2 pesticide residues
e. Soil erosion
f. Salinization
g. Water vessel discharges
h. Thermal pollution