More rainfall is received at West Coast Park in January than in August. 

January is the wet phase of the Northeast Monsoon, where the Inter-Tropical Convergence Zone(ITCZ) is located closest to Singapore compared to the rest of the year. As the ITCZ is a band of low air pressure, onshore winds blowing from the North-east arrive from subtropical areas of high pressure, such as from the South China Sea to the low pressure zone of the ITCZ. These winds collect moisture evaporated from oceans as they blow towards the ITCZ, bringing about heavy precipitation as these moist, unstable winds pass over Singapore near the ITCZ as monsoon surges. 

September is the period where the southwest monsoon is underway. During this period, the ITCZ lies over India, directly south of the Himalayas. Hence, a low pressure zone develops over India, and onshore winds blow from the southwest direction towards India, bringing rainfall. In Singapore, there are also Sumatra squalls, which are thunderstorms formed in Sumatra and Java that travel eastwards to Singapore during the southwest monsoon, resulting in rainfall. 

However, rainfall in January is higher than in September, due to Singapore being in the direct path of monsoon wind movement in January as the ITCZ lies very close to Singapore, meaning Singapore takes the brunt of the rain. In September, Singapore is on the peripheral of monsoon wind activity, and most of the rainfall is mostly from neighbouring countries, whereas India receives the most rainfall.  

a)     Write down your methods for collection of primary/secondary data (including sampling)

-        What instruments/equipment do you need? 

·        Rain gauge

·        Should a rain gauge be unavailable, an empty cylinder of equal diameter throughout its length can be used(eg a soup can) along with a 30cm ruler. 

·        Wind vane

-        What types of data will you collect? 

·        (Primary) Average amount of rainfall collected in the rain gauges over two weeks.

·        (Secondary) Research done on rainfall patterns/trends in Singapore during monsoon seasons, as well as statistical data on amount of rainfall in Singapore. 

-        Which sampling method will you use? 

·        Systematic sampling

-        Justify the sampling method you have chosen. 

·        One rain gauge each is to be placed in the North, South, East and West regions of West Coast Park.

·        Rain gauges need to be placed in areas that meet specific criteria, hence the position of the gauges must be deliberated and cannot be random.

·        Rain gauges must be placed in open spaces that do not have buildings or trees over it, as runoff moisture from these structures can flow into the rain gauges, causing the amount of rainfall collected to be more than actual amount of rainfall over two weeks.

·        Rain gauges must also be placed on flat ground to prevent spilling of rainwater especially if rainwater collected reaches near the brim of the container, in particular when a cylinder is used as a makeshift rain gauge. 

•        What risks are present in your proposed GI? How can they be managed? 

One risk is that the rain gauges can be tipped or knocked over by people passing through the park. This can be managed by placing the rain gauges such that they are not in the way of the common foot paths of park-goers. Another risk is that rain gauges are prone to malfunction. For example, the funnel of the gauge may be clogged with debris, hindering the flow of rainfall into the gauge. This can be managed by conducting routine checks on the rain gauges every 3 days to ensure that they are functioning as they should to enable collection of data that is as accurate as possible.

•        What are the strengths and limitations of your research? 

One strength is that the research accounts for the entire area of West Coast Park, enabling one to get an accurate picture of the amount of rainfall in West Coast Park as the rain gauges are strategically spread out over the entirety of the park. However, this research is not representative of rainfall collected in the whole of Singapore. Despite Singapore being a very small country, there are bound to be variations in rainfall across the island. This research only accounts for rainfall in the area of West Coast Park, and is hence limited in terms of space. Also, the research is limited in terms of how much rain can be collected. In the event that the rainfall overfills the rain gauges, the exact amount of rainfall collected can no longer be accurately measured. The maximum amount of rainfall that can be measured is the capacity the rain gauges are able to hold.

•        Are there any ethical considerations in your investigation? 

In order to place rain gauges in a public area such as East Coast Park, permission may be needed from authorities. Hence, before commencing with the investigation, permission should be granted from authorities. Also, the rain gauges should not become an obstruction to the path of park-goers and bring inconvenience. Thus, they should be placed at areas that do not obstruct paths whereby people normally travel through in the park.

 

 

 

 

Hypothesis: Rainfall in East Coast Park is highest from December to early January

 

b) Explain how you have come up with your research question or hypothesis

The Northeast monsoon occurs from December to early March. The early Northeast monsoon (wet phase) occurs from December to early January. This period of time is characterized by monsoon surges, or strong wind episodes that cause major rainfall events.  This occurs when the Intertropical Convergence Zone (ITCZ) is positioned near to Singapore.

 

Rain Gauge (measure amount of rainfall)

Wind Vane (determine wind direction)

 

I would use systematic sampling. I would mark out an area of East Coast Park and focus my investigation on that area. I would measure the amount of rainfall and the wind direction every 2 weeks. 

 

I would use the Internet to conduct online research to find out more about Singapore’s climate as well as the effects of the Northeast monsoon on rainfall. I would check to see if the expected results corroborate with my actual results. 

 

Risks: Rain gauges may overflow or be tipped over. Hence, making the volume of collected rainfall inaccurate. There is also the possibility of lightning during the collection of data. 

 

Limitations: The amount of rainfall in the rain gauges must be collected over a consistent period of time in order for the data collected to be accurate. However, external forces like people accidentally tipping over the rain gauges can still make the data inaccurate. 

How does the Sumatra Squalls which occur during the SW monsoon affect diurnal rainfall? 

Singapore lies in the tropical region where it receives high annual rainfall due to high insolation received all year round. However, there are monthly variations in rainfall received as it experiences the Northeast (NE) and Southwest (SW) Monsoon with the shifting of the Inter-tropical convergence belt (ITCZ). There is also variation in average diurnal rainfal range during the Northeast and Southwest Monsoon as he change in direction of trade winds result in an increased frequency of squall formation during the SW Monsoon occurring between June to September. Winds blow from the southeasterly to the southerly direction with occasional strong gusts of winds known as the ‘Sumatra Squalls’. When these squalls blow across the South China Sea as part of the Southwest Monsoon, they pick up more moisture  and bring intense convectional rainfall to Singapore. These periods of rainfall are characterised by their short duration and thunder, mainly occurring during the afternoon when the overhead sun is directly above the Earth’s surface and Singapore experiences the highest insolation rates within the day. 

> Equipment: rain gauge, timer

> Sampling: Spatial and systematic sampling where rain gauge is placed along a line transect at intervals of 5m along the coast of Area C in East Coast Park; allows for a greater area to be covered and an average be taken so that a better representation of rainfall received is obtained

> Equipment: Anemometer

> Sampling: Spatial and systematic sampling; taken every hour at the middle of the line transect 2m away from the shoreline along the foreshore zone; allows for an hourly recording that corresponds to rainfall received per hour and allows for an average to be taken 

> measure wind speed just before the thunderstorm occurs; avoid standing under a tree while measuring; use weather forecasting 

> always wear covered shoes when walking along the foreshore zone; be wary of surroundings and objects around (e.g broken glass bottle)

> avoid going within 1m of the shoreline; research on high tide levels and when they occur

The amount of rainfall experienced in East Coast Park, Singapore, is greatest in the month of December, as compared to February. 

Singapore experiences both the northeast and southwest monsoons, however, long-term climate records of rainfall in Singapore show that the wettest months are experienced in November and December. Conversely, the driest month occurs in February. This is due to the north-east monsoon (both dry and wet phases), with strong winds originating from China in the northern hemisphere during the early dry phase. Singapore lies near the equator, and is affected by the migration of the Inter-Tropical Convergence Zone (ITCZ). In December, the ITCZ moves toward the southern hemisphere (experiencing summer). This creates an area of high pressure in the northern hemisphere (low temperatures in winter), and winds will blow across South Asia and the South China Sea, picking up moisture and bringing it to South-east Asia. However, in the month of February, there is little rain experienced in Singapore, but as it is still part of the monsoon season, it brings dry winds to Singapore. 

Development of plan:
1. Primary data 

2. Secondary data