♥ Wednesday, April 8, 2009 ♥
Firstly I would like the emphasize that in this post, I would not post pictures/excerpts from our geog textbook as I think it is redundant to do so since it isn't that hard to refer to your geog textbook.
To start things off:
Mr Faizal was once again explaining to us about the water balance because we were unsure about it. This time, he drew a diagram so I took it down...note that not all aspects of the water balance are illustrated here.
Storm Hydrograph:
(enlarge the photo to have a closer view)
This one caused quite abit of a stir...
- Lag time: When a rain drop falls, the water level of a river does not shoot up immediately due to drainage. A rain drop still has to go through various processes occur before the water reaches the river. An example would be...imagine that you are a raindrop( so fun! ) and you precipitated down to earth. You land on the soil and infiltrate it. Thereafter, you would percolate and via throughflow, you reach the river. Hence, from this you can see, time was needed for the water to reach the river. This is lag time. Something to take note, a drainage basin with a steeper profile has less lag time and a drainage basin with a gentler profile has a longer lag time due to the speed at which the water reaches the river.
- Rising Limb: After some time, water from the drainage basin would arrive at the river and it's water level thus rises.
- Max. Capacity: When the river reaches it's maximum capacity and water is still flowing towards it, the river overflows its banks.
- Recession Limb: When it stops raining(precipitating) some water within the drainage basin which hasn't reached the river continues its journey to the river. After which, the water level of the river slowly recedes and this is reason for the recession limb.
- Rainfall Chart: The graph of the rainfall.
Yayy hope you understood it xD
Done by.. me. (:
Chunwai.
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