ah i'm finally here heh

HI MY DEAREST CLASSMATES I HAVE SOMETHING AMAZING TO SHOW YOU GUYS.













*GASPS* OMG DON'T YOU FIND THIS FAMILIAR?!
okay yes it's found in nj of course. but isn't this amazing, i mean,
IT'S A DRAIN. :O

okay let me tell you more about this seemingly insignificant drain okay :)

This drain is part of a larger system, which is known as the drainage system/basin. Drainage systems are commonly found in urban areas, which includes Singapore. Drainage systems play an important role in preventing flooding and controlling water flow in different areas.

When precipitation occurs, interception of the water by the grass (vegetation) occurs, resulting in infiltration of water. However, some of these precipitation falls straight into the drains, which will then flow down till it reaches a bigger channel, where all the big channels will then combine to form the channel storage (river).

Precipitation can also reach the channel storage via throughflow, which means water moving through the soil, and overland flow, which refers to water over the surface of the ground.













Here's where the drain from the above diagram links to!

Hope this is useful in helping you understand the importance of drainage systems! :)

-Shumin!

Drainages in Singapore

This is a picture indicates the drainage system in our Boarding school, which could be considered as a failure, I think. From the picture, it is clearly showed that the purpose of building such drainage system is to drive excess water away from the ground level. From the hole on the wall, we can predict that ground flow will occur. This is due to the fact that the lower level of the drainage. Water flows from high altitude to low altitude. In this sense, it would be nature to drive all the water when experiencing raining days. However, there is a problem underlying with this whole system. As clearly shown from the picture that water accumulates there, in this case, the whole drainage does not work within its full potential. We can clearly tell that water cannot go through the concrete wall. In this sense, we could try to build more holes so that water can come through.

Shengmu

ox bow lake

OX BOW LAKE.

sup peeps. its cheng yang here. im blogging about the ox bow lake! (moooo lol) anyway, i have no idea why its called an ox bow lake. (it says after researching on google that its cause it looks like the bow of the yoke used with oxen). Anyway, heres how an ox bow lake is formed:

1. there is a meander from the main stem
2. normally, water will flow according to the meander
3. however, when there is a flood the river would cross over the land onto the other end of the meander
4. if there is alot of water crosses over a long period of time, the land erodes
5. the eroded things are deposited at the start and ends of the original meander
6. cutting off the meander from the main stem, creating an ox bow lake

on a side note, its also called a billabong in australia(now we know where that name came from!)

hope you understand how its formed now!!!

byeeee

cheng yang.

River Delta

Up: Ural river delta (Bird-foot shape)

Down: Nile river delta (Delta shape)

A delta is a landform that is created at the river mouth where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as

the flow leaves the mouth of the river. Over long periods of time, this deposition builds the characteristic geographic pattern of a river delta.

(Wikipedia definition)

What is sediment?

Sediment is naturally-occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluid such as wind, water, or ice, and/or by the force of gravity acting on the particle itself.

(Wikipedia definition)

In this case, sediment that are deposited in a river delta is often very fertile, therefore most of the agricultural activities are on river delta.

How sediment is deposited?

When the river channel's flow enters a standing water (non-moving water), since the width of the channel is expanded, its flowing speed decreases. When it decreases, sediments starts to dropping out of the flow, and deposit.

Sediment could also deposit in the middle of the river, since the slope decreases. Deltas are formed.

Based on what erode the delta, which could be river flow itself, the waves, or tides, different type of delta which have different shape, will be formed.

Those types are

_ River-dominated delta: Bird-foot shape

_ Wave-dominated delta: Delta shape (Greek capital Delta)

_ Tide-dominated delta: Dendritic structure.

...

Vu Xuan Kim Cuong

hi hi. this is the drainage canal at bishan park. nice right?? anyways. most of the small drains around the area drains into this larger drain which then carries the water to either the sea or other reservoirs. did you all know that most of our drainage systems collect rainwater and then transports them to the 17 reservoirs around Singapore?? cool right? :D this allows Singapore to harvest urban stormwater on a large scale for its water supply so we have more water to drink YAY! :D

~xinxian

Floodplain

Introduction

A floodplain is flat land adjacent to a stream or river that experiences occasional or periodic flooding. It includes the floodway, which consists of the streamchannel and adjacent areas that carry flood flows, and the flood fringe, which are areas covered by the flood, but which do not experience a strong current.

Physical geography

Floodplains are formed by a meander eroding sideways as it travels downstream. When a river breaks its banks and floods, it leaves behind layers of rock and mud. These gradually build up to create the floor of the flood plain. Floodplains generally contain unconsolidated sediments, often extending below the bed of the stream. These are accumulations of sand, gravel, loam and silt, and are often important aquifers, the water drawn from them being pre-filtered compared to the water in the stream.Geologically ancient floodplains are often represented in the landscape by fluvial terraces. These are old floodplains that remain relatively high above the present floodplain and indicate former courses of a stream.

The floodplain during its formation is marked by meandering or anastomotic streams, ox-bow lakes andbayous, marshes or stagnant pools, and is occasionally completely covered with water. When the drainage system has ceased to act or is entirely diverted for any reason, the floodplain may become a level area of great fertility, similar in appearance to the floor of an old lake. The floodplain differs, however, because it is not altogether flat. It has a gentle slope down-stream, and often, for a distance, from the side towards the center.

Ecology

Floodplains can support particularly rich ecosystems, both in quantity and diversity. They are a category of riparian zones or systems. A floodplain can contain 100 or even 1000 times as many species as a river. Wetting of the floodplain soil releases an immediate surge of nutrients: those left over from the last flood, and those that result from the rapid decomposition of organic matter that has accumulated since then. Microscopic organisms thrive and larger species enter a rapid breeding cycle. Opportunistic feeders (particularly birds) move in to take advantage. The production of nutrients peaks and falls away quickly; however the surge of new growth endures for some time. This makes floodplains particularly valuable for agriculture.

Markedly different species grow in floodplains than grow outside of floodplains. For instance, riparian trees (that grow in floodplains) tend to be very tolerant of root disturbance and tend to be very quick-growing, compared to non-riparian trees.

Interaction with society

In some tropical floodplain areas such as the Inner Niger Delta of Mali, annual flooding events are a natural part of the local ecology and rural economy, allowing for the raising of crops throughrecessional agriculture. But in Bangladesh, which occupies the Ganges Delta, the advantages provided by the richness of the alluvial soil of floodplains are severely offset by frequent floods brought on bycyclones and annual monsoon rains, which cause severe economic disruption and loss of human life in this densely-populated region.

JH404 Zhang Yiyuan

Drains

Hello, i am here to inform you how a drainage basin works.

Firstly, what is a drainage basin?
It is the area of land of land where water from rain and melting snow or ice drains downhill into a body of water, such as a river, lake or reservoir.

A drainage basin is an "open" system, where it has inputs and outputs.

Inputs include precipitation while outputs include evaporation and transpiration.

So, basically, how does the water move through the drainage system. There are many ways like infiltration, througflow, overlandflow and groundwater flow.

The first picture is a picture of a Singapore drainage basin, also known as the "kelong". It is a channel that transports water to other areas such as the sea.

When there is a high amount of rain, water is not able to infiltrate the ground as the soil is holding its field capacity. When the infiltration capacity is exceeded, water is unable to soak away into the soil and overland flow occurs. This could result in major floods.

Shu Yih

Waterfall

what is a waterfall

A waterfall is a place where flowing water rapidly drops in elevation as it flows over a steep region or a cliff. Some waterfalls are used to generate hydro-electric power.

How does waterfall form?
Waterfalls are most commonly formed when a river is young.
At these times the channel is often narrow and deep. When the river courses over resistant rock, erosion happens slowly, while downstream the erosion occurs more rapidly. As the watercourse increases its velocity at the edge of the waterfall, it plucks material from the riverbed. Whirlpools created in the turbulence as well as sand and stones carried by the watercourse increase the erosion capacity. This causes the waterfall to carve deeper into the bed and to recede upstream. Often over time, the waterfall will recede back to form a canyon or gorge downstream as it recedes upstream, and it will carve deeper into the ridge above it. The rate of retreat for waterfall can be as high as one and half metres per year.
Often, the rock stratum just below the more resistant shelf will be of a softer type, meaning that undercutting due to splashback will occur here to form a shallow cave-like formation known as a rock shelter or plunge pool under and behind the waterfall. Eventually, the outcropping, more resistant cap rock will collapse under pressure to add blocks of rock to the base of the waterfall. These blocks of rock are then broken down into smaller boulders by attrition as they collide with each other, and they also erode the base of the waterfall by abrasion, creating a deep plunge pool or gorge.
Streams become wider and shallower just above waterfalls due to flowing over the rock shelf, and there is usually a deep pool just below the waterfall because of the kinetic energy of the water hitting the bottom. Waterfalls normally form in a rocky area due to erosion. After a long period of being fully formed, the water falling off the ledge will retreat, causing a horizontal pit parallel to the waterfall wall. Eventually, as the pit grows deeper, the waterfall collapses to be replaced by a steeply sloping stretch of river bed
A river sometimes flows over a large step in the rocks that may have been formed by a fault line. Waterfalls can occur along the edge of a glacial trough, whereby a stream or river flowing into a glacier continues to flow into a valley after the glacier has receded or melted. The large waterfalls in Yosemite Valley are examples of this phenomenon. The rivers are flowing from hanging valleys. Another cause of waterfall formation is where two rivers met and one flows faster then the other. The difference in the level of the beds may result in what is called a hanging valley.

Wang Zhaolin

drainnssssssss

Helloo, i am here to tell y'all more about the drainage system next to bukit timah plaza! :) the pictures above was taken after it rained super heavily, and as you can see, quite alot of the precipitation had flowed into the drain. as you know from the previous posts, the drain above is part of a larger drainage basin system which helps convey water from all around the country to a common area, like a river or a reservoir for Singapore's case :D. the water you see here is probably going to be in your cup next time, after going through cleansing (:

yeah so anyway, heavy rain that day, leading to precipitation percolating into soil and being intercepted by the grass nearby. however, as we can infer from the rainwater in the drain, overland flow occurred, and many reasons can explain for this! for example, the infiltration capacity (the rate of which water soaks into the soil) could have been exceeded; the zone of saturation could have increased, causing the water table to move up and causing the zone of aeration to decrease in size, leading to the soil being too saturated for more intake of precipitation! :( therefore, overland flow into the drains! :D and yepp like what everyone had said, a drainage system is an 'open' system, so evapotranspiration is bound to occur :) we are lucky to have such a drainage system, or else everytime it rains in Singapore, there would be flooding which is baddddd.

okay hope you understood! gogo study for interims NEXT WEEK :( good luckkk 04 <3!

Yuxian! :D

Hello. Si Jia here(: This is the picture of Kallang Basin. It’s really pretty but my hand sort of covered the bottom of the picture-.- But anyways, you have no idea how big Kallang Basin is! If you have no idea where it is, you can see it from the highway, or at the indoor stadium(: Oh, the water’s super clear too:D

Be glad k! Kallang Basin is like the biggest drainage basin in Singapore! Bet you all didn’t know that this place is being drained by rivers like Kallang, Geylang, Rochor and Whampoa rivers!(: Maybe all your tap water is from Kallang Basin!:O But, it’s clean anyway(:

Yeps, as you all can see, when there’s rain (precipitation), it either flows directly into the drainage basin itself, or it gets intercepted by the grassland at the background. So then, you all better know what will happen, if not you ought to slap yourself! Well, the water gets infiltrated into the soil, then there’s the normal process, the throughflow in the zone of aeration and the baseflow in the zone of saturation:D And the water can then flow towards the reservoirs and rivers nearby((: BUT! Remember, if there’s input, there will always be output too! Must balance right:D The outputs are evaporation and transpiration from the grasslands/trees(:

So cool rights(: You all can totally admire the Kallang Basin and at the same time camwhore:D We can have our next class outing there!(:

hi everyone. heres the picture of the drain.

its part of a larger system known as the drainage system/basin.

this particular part is a channel and it will flow down till it meets a bigger channel and this channel will join with other channel and finally join with the main river. hence it can be considered as a tributary.

on another note, i would like to point out a difference in the 2 terms which some people use interchangeably but in technical sense is different. they are watershed and drainage basin/catchment area.

now in layman terms and in the U.S. these are used interchangeably, but just to be on the safe side, the drainage basin is the total area of land where water in that land will flow into a body of water (e.g a river) while a watershed is the divide that demarcates and distinguishes/separate one drainage basin from another.

anyways, have a nice long weekend peeps! p.s. we will miss chinese class on mondays for 2 weeks. hoooooorrrrraaaayyyy!

cheers

leonard