Saturday, 27 October 2007 @ 10/27/2007 11:07:00 am
♥| rivers ? O.O
Okay , accomplished one chapter . I finish the notes for chapter 17 , drainage basin & rivers . Want the notes ? Haha , I'll just post it up here . Here you go ! :D
eye-blinding ! :x
DRAINAGE BAISINS .
a. Drainage basins a.k.a River basin .
> an area of land drained by a river and its tributaries .
> Source ; where the river starts .
Tributary ; a stream or small river tat flowes into a bigger one .
Watershed ; the bounday of a drainage basin .
Confluence ; Where a small river joins a larger one .
Mouth ; end of the river .
b. Hydrological cycle a.k.a Water cycle .
> Water is a non-renewable resource .
> Constant movement , or transfer , of water between the sea , land and atmosphere - hydrological cycle a.k.a water cycle .
> surface runoff -> ( ocean , sea , lake ) -> transpiration , evaporation -> ( water vapour is blown inland by the wind ) ( moist air is forced to rise , cools and condenses ) -> condensation -> precipitation [ & it repeats itself . ]
> Surface runoff ; the transfer of water across the land and into the sea or a lake .
Transpiration ; the transfer of water from plants into the air as watervapour .
Evaporation ; the transfer of water from the surface into the air as water vapour .
Condensation ; the change of water vapour in the air into water droplets . these are visible as clouds .
Precipitation ; the transfer of water from the air to the land . it can be rain , hail , sleet or snow .
c. Drainage basin system a.k.a River basin system .
> Part of the hydrological cycle that operates on land - drainage basin system a.k.a river basin system .
> precipitation -> interception -> surface storage -> infiltration -> soil storage -> percolation -> groundwater
-> surface runoff -> throughflow -> groundwater flow
-> river channel
> Precipitation ; rain , hail , sleet , snow .
Interception ; when water droplets collect on trees and plants .
Surface storage ; when water lies on the ground as puddles or lakes .
Soil moisture ; water stored in the soil and broken rocks near the surface .
Groundwater ; water stored in porous rocks deep below the ground .
Surface runoff ; water moving across the ground as a stream or rier .
Throughflow ; water flowing downhill through the soil .
Inflitration ; when surface water soaks into the soil .
Percolation ; water moving downwards through the soil into rocks below .
Groundwater flow ; very slow water movement deep below the ground .
> Water table ; the level at which saturation occurs .
Saturation ; when the soil or rock is full of moisture .
RIVERS .
a. River processes .
> rivers help shape the landscape , afferct human activity , and are a valuable resours .
> shape the land through processes of erosion , transportation & deposition .
> Erosion ; wearing away of the land , most erosion occurs when a river is in flood . this is when it flows fastest and can carry huge amounts of material .
- attrition ; material is moved along the river bed , collides with other material and breaks up into smaller pieces .
- corrasion ; caused by fine material rubbing against the river bank . the action is rather like that of sandpaper .
- corrosion ; a form of chemical erosion . the banks and bed of the river are dissolved by acids in the water .
- hydraulic action ; the force of water hitting the banks of the river . it wears them away and causes them to collapse .
> Deposition ; this is the laying down or dumping of material . it happens when a river slows and loses energy . this may be during a dry spell , on the inside of a river bend , or when the river reaches the sea .
> Transportation ; this is the movement of eroded material . the material includes sand particles , pebbles and even large boulders . there are four ways that material can be trasnportaed .
- traction ; large rocks and boulders are rolled along the bed of a river .
- saltation ; smaller stones are bounced along the bed of a river in a leaping frogging movement .
- suspension ; fine material is light enough to be carried by the river . this material may discolour the water .
- solution ; some minerals dissolve in the water . these are always present in the river .
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