Canterbury Plains EarthCache
RAYZR: as per below
to many hassles with this EC
caching is supposed to be fun
the answers supplied to me were incorrect 3 times
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Difficulty:
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Size: 
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Most people assume the Canterbury Plains are a featureless expanse
of farmland, well I was thinking back to my 5th Form Geography
class and realised that the is more to the Plains than meets the
eye.
The Canterbury Plains are bounded by the foothills of the Southern alps to the west and the east coast of the South Island at the pacific ocean. The plains extend from the Waitaki river in the South to the start of the Hundalee hills to the North. They cover an area of 42,200 sq Km and were formed by quaternary moraine deposited during Glacial periods between 3 million and 10,000 years ago. The gravel was reworked over time to form shingle fans making up the river beds of the major water ways in the area. The largest river is the Rakaia which has cut a bed 100m deep into the plains and extends 150km from the Southern alps to where it enters the Pacific ocean. These braided river systems are unique and extensive system like this are only found in Canada, Alaska, the Himilaya, the Yellow River, and of course these ones that we are concerned about in the South Island of New Zealand. These rivers can be formed in two ways, the first is by the river bed having a high gradient, and the second is by having high sediment deposits. The Canterbury plains Braided rivers meet both these criteria. Due to the high amounts of sedimentary shingle being moved through the river systems they cover are large expanse but are contained within stable river banks. The braided river is shallow and fast flowing, made up of many seperate channels split by small shingle Islands known as Braid Bars. The layout of the river bed, channels and Bars is very temporary, as each time the river floods its characteristics are altered.
The Canterbury Plains are widely used for farming, but this is a real challenge as they are prone to drought for two reasons. The highly fertile soil is reasoanably thin, sitting on top of highly poris shingle bed. This makes water drainage high, and therefore water retention extremely difficult. Secondly, the plains are exposed to a peruliar weather pattern, the Nor' West arch.
This "Nor'West Arch" condition is quite unique to the South Island of New Zealand, and is caused when warm moist which travelled across the Tasman sea comes into contact South Island. The air is forced up over the Southern Alps, this causes it to be rapidly cooled, and therefore cannot retain it's moisture. This leads to rain falling on the West coast and west side of the alps. The effect of this on the Canterbury Plains is hot, dry, and at times gale force winds. Any remaining moisture in the air condenses air reaches high altitude and becomes visible, seen as bands of white cloud otherwise clear blue sky. This weather condition in also known as a "Foehn Wind". Apart from obvious effects this weather has on the land, there is also a curious psycological that it has on residents and visitors to the plains. Studies have shown about 10% of people exposed to these winds can feel euphoric or energised, but the bulk are effected very different way. About 90% of people exposed for extended Nor'West conditions feel lacking in energy, irritable, tired, and in extreme cases depressed. These studies also found an alarming fact that there is a notable increase suicide rate during prolonged Nor'West wind conditions.
To Log this cache will need complete all of the following tasks;
1. The Rakaia river bridge (as defined by signs either end, Bridge 3998 (White) and Rakaia River (Yellow)) is longest road bridge in New Zealand. What is the length (In metres) of the road bridge as defined? (+/-10m) (E-mail me your answer)
2. E-mail me the names of at least 4 Canterbury Braided rivers.
3. With your log, post a photo of a Canterbury Braided river, your photo must included your GPSr.
Additional Hints
(No hints available.)