Flooding in Bangkok

This year, the 2011 Thailand flood has been more severe than the preceding annual floods that Thailand faces for a number of reasons. Firstly, the geography of the land in Thailand naturally contributes to the flooding, as Thailand is geographically sloped. Therefore the rainwater from the north flows towards the gulf of Thailand, however where before forests delayed and absorbed the water and acted as natural dams and water gates, the replacement of these forests by cement dams and industrial parks and housing estates for the sake of human development has facilitated the flood as the water has reached uncontrollable levels unanticipated by humans. In addition, the heavy rains have also contributed to the situation.

Currently, the situation with Bangkok is that there are 100 billion cubic meters of water on land that need to reach the sea, and they can go through Tha Jeen River, Bang Pakong River and Chao Praya River. To do this using the river channels only it will take 50 days, and so by using the 1600 square meters of land in Bangkok, they can allow the water to reach chest level at most to relieve outer areas of the floodwaters. However, to prevent flooding the government plan to protect the water levees from flooding inner Bangkok, although despite this Bangkok will still be inundated for one month as we wait for the water to drain out to the sea.

The risk now is the water pressure pushing against the levees, and the fear that the levees will break. However, even professors can only make estimates about the pressure of the water and so the only thing to do is to stay calm and prepare.

This links to syllabus statement 8.4 “the ways in which processes operating within the water cycle affect development” which examines the causes of flooding and drought, and this topic is highly relevant as according to the video much of the flooding has been caused by human intervention in the natural flow of the water cycle. As we have learnt, the water cycle begins with evaporation and condensation and precipitation, but an equally important aspect of the water cycle is the surface run-off and the infiltration and ground-water storage which has now been impaired by the development of human settlements and industrial activity in Thailand. Where before the water could infiltrate to bedrock level through the soil and the tiny gaps in the rocks, the replacement of the soil with cement dams has meant that even with more water the capacity of the dams remain the same and so the human intervention with the natural process has inevitably led to the flooding.  

Answer for EM Exam question 1A

Explain why El Nino causes a serious decline of the Peruvian fishery:
Firstly the El nino causes a rise in sea temperature and a convection current will occur where the warmer, less dense water with few minerals rise to the top but the colder Humboldt current sinks to the bottom. With the inversion in temperature the cold water with all the minerals is trapped underneath the warm water, making it unavailable to the phytoplankton who grow near the surface for light. Therefore with less phytoplankton the anchovy will have less to feed on causing a decline in the number of primary consumers such as anchovy which will set off repercussions for the whole food chain. Therefore with less fish in the ocean, the Peruvian fishing industry  fails.

Formation of a Cyclone

Question: Starting with the phrase 'high sea temperature', use your knowledge and the diagram to explain the formation of a cycle

Answer: When high sea temperatures occur, the heat causes the air particles to rise, and as the particles gain energy more particles rise due to the air escaping from high to low pressure like in a convection current, so when the air particles reach a greater height they will cool and fall. As more air particles rise and cool to sink, they will rush towards the low pressure centre and with all the rushing particles will form the most energy stable solution, creating a vortex, and the latent energy within the cyclone will cause the damage. 

Past paper questions: Los Angeles

1. a) i) Atmospheric pollution from traffic and industry may be worse in places with a dry climate as firstly, with no rain the pollutants are more likely to remain trapped near the surface layer of air, especially in inversion of temperatures. When an inversion of temperature occurs this is when a layer of hot air traps a layer of cool air below, not allowing the air below the inversion layer to move, trapping the pollutants. Secondly, hot climates cause air to rise, lowering the air pressure and density - trapping layers of pollutants in the air.
ii) Pollution could be worse in less developed countries as there is less management for car pollution, and it is more difficult in developing countries as they have little money to spend on protecting the environment without adding to production costs, and so whilst in LA it would be possible to implement mandatory use of catalytic converters it would be far too expensive to be viable

Extension questions

a) i) Plan one is only testing at ONE point
ii) By having 4 sites there are more results taken meaning it is easier to identify anomalous results, and by asking the weight of the cardboard it is easier to record/measure with reliable and standard parameters ie. kg
iii) Whereas in Plan two it is possible, and very likely, that each collector will only know an estimate of the weight of their cardboard if the students measured the cardboard and plastic themselves their results would be more accurate

Burning Sugar Cane

Because the farmer only burns the dry parts of the plant which contains a little sugar, the carbon dioxide released is not much (as there is only a little bit of sugar that is combusted) and can easily be absorbed into the surrounding trees through the process of photosynthesis, therefore not affecting the atmosphere on any scale.

Causes of Atmospheric Pollution

Unit 3.2: page 125 in the Textbook

Carbon Dioxide: http://www.epa.gov/climatechange/emissions/co2_human.html

Sources:

1. Deforestation and burning wood

2. Burning fossil fuels

Effects: 

1. Traps more of the heat radiated from the surface

2. Increases Earth's atmosphere, causing Global Warming

3. Rising sea levels

4. Changes in world weather

Page 132: CFCs http://www.pollutionissues.com/Br-Co/CFCs-Chlorofluorocarbons.html

Sources: 

1. Propellants in aerosol spray cans - hair spray, deodorants, insect killers

2. Coolants used in refirgerators and air-conditioning systems

Effects:1. Persist in the atmospehre for a long time, causing the breakdown of the Ozone System (hole in the ozone layer over Antartica)

Page 135: Methane http://epa.gov/methane/sources.html

Sources:

1. Deforestation

2. Decomposition of waste

3. Rice and cattle farming (rotting vegetation)

Effects:

1. Contributes to Greenhouse gases, leading to:

Rising sea levels, changes in world weather and global warming