Geography - Case Studies T4

Question 1

Omaha Coastal Environment:

What type of sand is Omaha composed of?

Answer 1

Mangatawhiri Spit is composed of medium sand (0.5-2mm diameter) on ocean side and fine sand and silt (<0.5mm) on the harbour side. Origin of most sand from volcanic rocks around Rotorua and Taupo, brought to Omaha by Waikato River when it ran into the Firth of Thames.

Question 2

Omaha Coastal Environment:

Give history of human activity.

Answer 2

Mangatawhiri spit has been farmed since 1930.
Sand was dredged from offshore zone between 1942 and 1963.
In 1970, original subdivision of houses was built. Golf course was built, draining out the salt marsh.
Omaha has 1million visitors per year walk over the dunes and onto beach.

Question 3

Omaha Coastal Environment:

Where is Omaha?

Answer 3

80km north of Auckland on east coast of Rodney District, between Cape Rodney and Takatu Point. Spit is called Mangatawhiri Spit, extendeds between Whangateau Harbour to the west, and Little Omaha Bay to the east.

Question 4

Omaha Coastal Environment:

Describe longshore drift at Omaha.

Answer 4

Longshore drift transports sand northwards along spit from Te Kie point to the end of the spit, stopped by 3 groynes, named Northern, Swash, and Southern.