What is Development?
- the living conditions and lifestyle of people
- access to education, health care and other basic amenities
- measurement of material and non-material aspects of life
- e.g. access to leisure
Happy Chinese New Year!!!
Wishing all my students Happy Chinese New Year!
May the year of Dragon brings one and all to a greater height!
新年快乐, 万事如意!
Energy of Rivers
The energy of the river is determined by 2 factors- speed of flow and volume of water. Therefore, when the speed of flow and the volume of water is high, the energy of the river is also high. We say that there is a positive relationship between energy of river and the speed of flow and the volume of water that the river is carrying.
There are 3 factors affecting the speed of the river. (GRoW)
1) Gradient of channel
Rivers flow downhill from a height due to gravity. Therefore, a steep gradient will cause the speed of the river to be fast.
2) Roughness of channel
A smooth channel without obstacles like rocks and boulders will increase the speed of the river.
3) Wetted perimeter
The lesser the water that contact the river channel, the higher the speed of flow due to less friction.
There are 4 factors affecting the volume of water in the river. (SPCPetrol)
1) Size of Drainage Basin
The larger the drainage basin, the higher the volume of water of the river.
2) Presence of Vegetation
More vegetation will result in higher interception and lower runoff, resulting in lower volume of water. Vegetation will also delay the amount of water that reaches the river in a short time, preventing floods.
3) Climate
If the rainfall is high, the river will have a higher volume of water.
Climate will also determine the amount of vegetation in the river vicinity.
4) Permeability of Rocks
High premeability will result in low volume of water due to decrease in runoff.
Blue Revolution
Blue Revolution was a social and technological movement that started in the 1970s to protect marine life and to ensure sufficient seafood, especially fish, for present and future generations.
Fish researching results in scientist developing ways to increase the fertility of fish, to improve their growth rate and increase their resistance to disease. This hence ensures a stable supply of harvested fish, thus increases the amount of fishes available for consumption.
Benefits
- Sustainable fishing. Ensure sufficient seafood to meet increase in demand as population grows.
- Social – Source of cheap protein for the poor. As the supply of fish increases surpassing the demand, the price reduced dramatically. Fish is made affordable to the poor. This could be the solution to the protein deficiency in the LDCs.
- Social – Reliable supply of fish supply as the fishes are reared under controlled condition as compared to the wild catches which are determined by the weather. Source of food for the country.
- Social – Source of employment and income for the locals. This provides a consistent source of income, improving their purchasing power as well as increasing their demand for goods and services. Their standard of living improved.
- Economic – New employment opportunities for the locals e.g. in the manufacturing of fish feed, vaccines, exporting exotic fishes. This helps to reduce the rate of unemployment in the country.
Threats
- Fear of unknown consequences. The genetically modified fishes may have unknown effects on humans.
- Loss of natural species. When the fishes escape from captivity, they may breed in the wild and genetically pollute the natural species.
- Many poor farmers especially in LDC are unable to afford Blue Revolution technologies and R&D activities. Price of fishes have fallen due to increase in production and result in less income for these farmers
River Processes (Erosion)
Erosion
occurs when rocks and other materials are broken into smaller pieces and moved downstream by the energy of the river.
The four processes of erosion are:
- Hydraulic action where fast-moving water loosens and dislodges the rocks and soil from river bed and banks.
- Corrasion where rock fragments that are dragged along by the flow of the river, grind against the river bed and banks.
- Attrition where eroded materials in the river constantly collide against each other and break down into smaller pieces.
- Solution where minerals in the rock dissolve in the carbonic acid in the river due to acid rain.
To remember:
” I was a piece of rock by the river bank, broken off by hydraulic action. I was carried by the river causing corrasion as I erode the river bed and banks. I collide against the other rocks, resulting in attrition. I’m going to be dissolved in solution as there’s carbonic acid in the water. “
(By student: Hot Chicks Affect Success)
Different Parts of a River
The imaginary boundary that separates one drainage basin from another is known as the Watershed.
The whole area drained by a river and its tributaries is known as the Drainage Basin.
Benefits & Threats of Using Chemicals in Food Production
“The use of chemicals in Green Revolution has led to an increase in the crop yield.”
Discuss the effectiveness of this measure.
+ land can be used continuous
+ provide nutrients for healthy plants growth
+ meet specific needs of plants
+ maximize output
- imbalance in soil nutrients
(2 or 3 nutrients, no humus)
- eutrophication in water bodies
(excess fertilizers, growth of algae & plankton, lack of oxygen, decomposition)
+ destroy pests
+ protect harvest
+ minimize crops destroyed by pests
- seep into ground, water pollution
(contaminate water, kill aquatic plants and animals)
+ destroy weeds that compete for nutrients with crops
+ save time and labour for removing weeds
- water pollution
(reduce the quality of water)
3 Courses of the River
Upper Course
At the upper course of the river, the gradient is very steep and the river channel is narrow and shallow. The amount of water is low and the speed of the water is very fast. Due to the vertical erosion, the river channel is of a steep V shape.
Middle Course
At the middle course, the gradient of the river is not as steep as the upper course. The speed of the river reduces compared to the upper course. The river channel is wider and deeper as the tributaries join the main river. The river channel is U-shaped.
Lower Course
At the lower course, the gradient of the river is almost flat. The speed of the river is the slowest at this point and the volume of water is the highest of all three courses.The river channel is also the widest and deepest, taking a wide U-shape.
Hydrological Cycle
1) Evaporation – water evaporates and changes to water vapour.
2) Transpiration – plants and animals give out water vapour through transpiration. (when they breathe)
3) Condensation – the water vapour condenses into water droplets which combine to form clouds.
4) Precipitation – when the clouds become too heavy, the water fall as rain in a process known as precipitation.
5) Surface runoff – water flows on the ground surface as surface runoff into streams and rivers.
6) Groundwater – water seeps into the ground and may be absorbed by plants or flow to rivers, lakes or the sea.
Benefits and Problems of Irrigation
Effects of Intensifying Food Production
Benefits of Irrigation
Irrigation can ensure a constant supply of water to the crops through artificial means during the dry season.
Problems of Irrigation
Irrigation can lead to salinisation where the building up of salts can result in damaged farmland. When water is used up by the plants or evaporated, salt is left behind on the land and the naturally occurring salts will lower the quality of the soil
The construction of dams lead to more minerals being dissolved in the water that is used for irrigation, thus increasing the salinity of the soil.
Groundwater used for irrigation is rich in minerals and salts. In some countries like Libya, seawater may seep into groundwater that is used for irrigation and the salinity of the soil is increased.
Over irrigation can result in waterlogging where air and nutrients cannot reach the roots of the crops and causes the crops to wither and die.
