Wednesday, August 24, 2011
Reflection on Research(Gracia)
From the research, I've learnt that seawater is actually alkaline, with a pH of 8. Also, I learnt that the activities along the beach could affect the seawater. At C, there was a strong fish smell because the seawater was from the left side of the jetty. It is dirtier and thus, probably has a more fishy smell. The points with less rubbish spotted were also not cloudy as the ones with lots of rubbish. I feel that the seaweed washed-up on shore was because of the waves. The water at B, the control, showed that it was the cleanest as there were no human activities there.
In photographs taken, the alkalinity of the seawater showed that part of break walls and rocks were corroded as seen in colour differences. Also, when the experiment was conducted, I learnt that unfiltered seawater has more impurities in it as compared to when it is filtered. This can be told from the time taken to boil and evaporate the pure water in the seawater until salt is left.
After the experiment, it can be concluded that the cleaner the seawater is, the more salt crystals it can form and that the cleaner the water, the less salt is formed.
In other photographs, breakwalls show the growth of algae. This is also a prove that seawater is alkaline because alkaline components in seawater like nitrate and phosphate encourages the growth of algae on areas that frequently come into contact with water.
In conclusion, I learnt that seawater at East coast Beach is polluted and is alkaline.
Water Pollution Project (Gracia, Nicole, Kimberley, JiaYu)
Research:
Bottle A- breakwall (camping, more human activities going on, No rubbish on shore)
Bottle B- control (no human activities, more birds, No rubbish on shore)
Bottle C- left side of jetty (a lot of rubbish on shore, strong waves, washed-up seaweed, fishing)
Bottle D- right side of jetty (No rubbish on shore, small waves)
Smell
A- no smell
B- no smell
C- strong fishy smell
D- mild fishy smell
Clarity (1)least clear----(4)clearest
A- (3)
B- (4)
C- (2)
D- (1)
pH
The seawater samples all turned blue when we dropped pH paper into them. Thus, all of the samples have a pH around 8-9.
Litmus paper test:
All the seawater samples turned the red litmus paper blue but for the blue litmus paper, the colour remained unchanged.
Residue/salt (1)most----(4)least
A- (1)
B- (2)
C- (3)
D- (4)
Salt crystal amount for unfiltered seawater (1)most----(4)least
A- (3)
B- (2)
C- (4)
D- (1)
Time taken for water to evaporate (filtered)
A- 11.55 min
B- 10.57 min
C- 13.09 min
D- 12.33 min
Time taken for water to evaporate (unfiltered)
A- 15.11 min
B- 12.58 min
C- 18.05 min
D- 10.54 min
Conclusion:
We found out that seawater is alkaline with a pH of about 8-9 instead of acidic as mentioned in our hypothesis and that the seawater at East Coast beach is polluted because of the photo evidences of rocks and break walls that have eroded/corroded slightly. It is polluted because overall, unfiltered seawater takes longer to evaporate, meaning that it is less pure than filtered seawater that takes a faster time to evaporate. This proves that the original seawater samples collected had more impurities in it.
- Water Pollution
- The seawater at East Coast Beach is polluted and is acidic.
- clarity of seawater
- whether the seawater is acidic or alkaline
- type of dirt particles or rubbish in the seawater
- photographs of evidences of polluted water
- Walk along East Coach Beach and identify 4 points along the sea with different activities going on.
- Collect a sample (1 bottle) of seawater at the 4 different locations.
- Label point A, B, C or D on the bottles.
- Pour out 2 beakers of 50cm3 of seawater from each sample.
- Observe the clarity of the seawater and smell it. Record down observations.
- Pour out some seawater from each sample into different test tubes.
- Dip red litmus paper and blue litmus paper into the seawater in each test tube then record observations.
- Drop pH paper into the test tube and record the pH.
- Filter one of the 2 beakers of seawater from each sample then boil in an evaporating dish until salt is left. Record observations and time.
- With the other beaker left, boil it straight in an evaporating dish without filtering until salt is left. Record observations and time.
- Compare the results for the different samples.
Bottle A- breakwall (camping, more human activities going on, No rubbish on shore)
Bottle B- control (no human activities, more birds, No rubbish on shore)
Bottle C- left side of jetty (a lot of rubbish on shore, strong waves, washed-up seaweed, fishing)
Bottle D- right side of jetty (No rubbish on shore, small waves)
Smell
A- no smell
B- no smell
C- strong fishy smell
D- mild fishy smell
Clarity (1)least clear----(4)clearest
A- (3)
B- (4)
C- (2)
D- (1)
pH
The seawater samples all turned blue when we dropped pH paper into them. Thus, all of the samples have a pH around 8-9.
Litmus paper test:
All the seawater samples turned the red litmus paper blue but for the blue litmus paper, the colour remained unchanged.
Residue/salt (1)most----(4)least
A- (1)
B- (2)
C- (3)
D- (4)
Salt crystal amount for unfiltered seawater (1)most----(4)least
A- (3)
B- (2)
C- (4)
D- (1)
Time taken for water to evaporate (filtered)
A- 11.55 min
B- 10.57 min
C- 13.09 min
D- 12.33 min
Time taken for water to evaporate (unfiltered)
A- 15.11 min
B- 12.58 min
C- 18.05 min
D- 10.54 min
Conclusion:
We found out that seawater is alkaline with a pH of about 8-9 instead of acidic as mentioned in our hypothesis and that the seawater at East Coast beach is polluted because of the photo evidences of rocks and break walls that have eroded/corroded slightly. It is polluted because overall, unfiltered seawater takes longer to evaporate, meaning that it is less pure than filtered seawater that takes a faster time to evaporate. This proves that the original seawater samples collected had more impurities in it.
Monday, August 22, 2011
Water Supply (Evangel Teo)
Water is needed for drinking and other uses such as cooking and cleaning. It is also used in industries and agriculture. There is limited amount of fresh water for human use. This problem of water shortage is referred to as water constraint.
Reasons for Water Constraint
Limited Supply of Fresh Water
Even though 70% of the Earth’s surface is covered by water, only 3% of that water is freshwater and only 1% of the total amount of water on Earth is freshwater readily available for human consumption, while the other 2% is frozen in the form of ice and snow.
Uneven distribution of fresh water
Some countries have a abundant supply of water while other countries have a lack of water. In Canada, there is an abundant amount of water while some countries in Africa have insufficient water.
Water Pollution
The fresh water resources are increasingly being polluted by human activities. Waste from factories and households are dumped into rivers which pollutes the water and this water cannot be used for activities such as drinking, fishing and swimming.
Rising Demand for Water
Population Growth
As the world's population increases, this means the total supply of freshwater will have to be shared among more people.
Growth of Agriculture
There is an increasing need to grow more food. Hence, up to three-quarters of the world's fresh supply is used for the watering of crops.
Growth of Industries
The growth of industries also contribute to a rise in water consumption because water plays an important part in the daily operations of these industries.
Changes in Lifestyle
When a country becomes more developed, people adopt modern lifestyles and can afford to buy items to provide them with convenience and comfort, such as washing machines and air conditioners.
Responses to Rising Demand for Water
Increasing the Price of Water
Some countries may increase the price of water so that people who do not want to pay more will be encouraged to use less water. However, when the price of water increases, only those who can afford to pay the high prices will be able to use the amount of water they want while poor people will not be able to pay the high prices of water.
Increasing Supply of Water
Increase catchment areas
A catchment area is where rain falls and is collected. An increase in catchment areas will lead to an increase to the amount of water collected. Nature reserves are often used as water catchment areas because forests can retain a supply of fresh water. The water collected from water catchment areas is cleaner than used water and does not contain salt which helps to keep the cost of water treatment down.
International Agreements
An international agree on water is an arrangement between 2 or more countries regarding the supply and the use of water resources over a specific period of time. When signing international agreements, countries discuss and negotiate terms on the buying or sharing of water resources. However these agreements do not last forever and will eventually expire.
Use of Technology
Recycling water or water reclamation and desalination are two examples of methods that make use of technology to increase the supply of water.
Used water can be converted into usable water. The used water is collected then treated at reclamation plants where the impurities are removed. The treated water can be further treated at industrial water works to produce industrial water, which is supplied to factories for purposes such as washing and cooling of machinery.
The process of removing salt from sea water is known as desalination. It is used to convert sea water into drinking water.There are various methods of desalination, one method is distillation and the other is reverse osmosis.
Although technology can convert used or sea water into drinking water, some people may not get used to the idea of drinking it as minerals are removed during the process, giving it a different taste.
4 National Taps
Tap 1: Water from local catchment areas
Tap 2: Imported water
Tap 3: NEWater
Tap 4: Desalinated water
Reflection:
I think we should conserve water and not waste it as it is a scarce resource and is essential for human beings' survival. Without water, we would be unable to survive. We also should not pollute water as there is already insufficient water for people around the world
Land Supply (Evangel Teo)
Land enables us to meet our basic needs for food and shelter. It can be used for growing crops, building houses and roads and setting up industries.
Reasons for Land Constraint
Rising Demand For Land
As the world population increases, there is an increased demand for housing, jobs, food and recreational spaces. A growing population will lead to an increase in demand for housing. More land will have to be used to build new houses for people. And to provide jobs for people, more industries and businesses will have to be created or expanded. This means more land is needed. To produce food to feed the increasing amount of people, more arable land is required to grow crops. However, only one-fifth of the Earth's surface is arable. There is also a increased demand for recreational spaces, from parks and nature reserves to swimming pools to golf courses and theatres, for people to enjoy and relax in. As an country develops, transport systems are developed and more roads have to be built for the movement of goods and to transport workers to travel between their workplace and home.
Limited Supply of Land
Only 30% of the Earth's surface is land. Furthermore, not all of this land can be used. Areas like swamps, marshes and low-lying coastal areas are constantly flooded with water and deserts are too dry to be used. Some land also has been damaged by mining or poor farming practices. Also, some land is reserved for special uses, such as water catchment areas and military training areas.
Responses to Rising Demand for Land
Increasing the price of land
The land supply in every country or city is limited. When the demand for land increases, and the available land area cannot meet with the increase in demand, the price of the land may increase. This is because some users might be willing to pay a higher price for the land and this will push up the price of the land. Increasing the price of land will discourage some people from using the land, hence reducing the demand.
Increasing the supply of land
Land Clearance
One of the ways to increase the supply of land is by land clearance, which is a process whereby empty plots of land are created for various landuses. This may be carried out by demolishing old buildings or by deforestation. After a piece of land is cleared, it can be developed for other uses. However, when land is cleared through deforestation, habitats of animals will be destroyed and many of them will die or become extinct.
Land Reclamation
Land reclamation is another way of increasing land supply. It is the creation of dry land from an area covered by water. Its also refers to the process of recovering land that is damaged or abandoned and making it usable again. There are three ways to reclaim land, landfill, empoldering and reclaiming derelict land. However, sand is needed to reclaim land and if the country does not have enough sand, they will have to purchase sand, which increases the overall cost. Also, for countries that are surrounded by other countries, there is an limit to the amount of land that can be reclaimed.They will not be able to extend too far out without entering other countries' territories. Land reclamation also has a negative impact on the environment when coastal habitats are destroyed.
Maximising Use of Existing Land
The last way is through maximising use of existing land by maximising urban and agriculture landuse.
Urban Landuse
Urban land can be maximised through mixed landuse and high density buildings. In mixed landuse projects, there is an combination of shopping malls, offices, houses and hotels in one area. High density buildings can also be built to house a large amount of people in a small area.
Agriculture Landuse
Irrigation
Countries need land to grow crops to provide food for people. Irrigation allows farmers to ensure that their crops have the right amount of water which will lead to greater amounts and wider varieties of crops, also lands that were not suitable for agriculture and be made arable.
Terracing
Crops cannot be grown in hilly areas as the slopes cause water to run off the slopes quickly and little water is retained by the soil. However, cultivation of crops on steep slopes has been made possible through terracing, which is creating flat strips of land by cutting a series of steps in to the slopes. It is an inexpensive way of increasing arable land and flat land allows modern machinery to be used.
Soil-less Farming
Crops can also be cultivated through soil-less farming, such as hydroponics and aeroponics, where crops can be grown closer together and more crops can be grown in a single area.
Reflection:
I feel that these measures to conserve land are effective, however, we will still run out of land to use as the population increases. The Singapore government has built high density buildings to maximise the land use and allow more people to live in a small area and also developed mixed landuse projects such as Suntec City, where there are offices, shops and hotels, all in walking distance of one another. There are also hydroponics and aeroponics farms in Singapore. These measure are effective, but they are not long-term and other ways of increasing the supply of land will have to be used.
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