Mangawhai-Pakiri Flashcards
Where is the Mangawhai-Pakiri coastline located?
It is a 20km stretch of coastline located in the North East coast of New Zealand’s northern most island, north of Auckland.
What is located behind the Mangawhai-Pakiri coastline?
A rural environment, made up of caravan parks, holdiay parks and a small area of natural housing. There is also a lot of agricultural activity.
What is Auckland’s significance to New Zealand?
Auckland is New Zealand’s largest city of 1.72 million people (1/3 of its population and 38% of its GDP), and fastest growing city, but not its capital. It is ranked #1 in the world for ease of doing business and gets 120,000 visitors annually.
What is being done on the Mangawhai-Pakiri coastline and why?
There is a large amount of sand mining being done on the Mangawhai-Pakiri coastline for economic uses in the growing city of Auckland
What are some examples of the uses of sand in modern society?
Sand is used for:
Making Glass,
Making concrete,
Filling Roads,
Reclaiming land,
Used in construction sites,
Beach nourishment.
Why is the sand at Mangawhai-Pakiri designated as the best option for mining?
It is very high quality, pure sand with high quartz contents and is very good for use in making high quality glass, and in nourishing very attractive beaches.
What is the value of quality sand in New Zealand?
NZ$25 per cubic metre of good quality sand for use in concrete, and NZ$40 per cubic metre for renourished sand.
Why is the Auckland in need of this high quality sand?
Auckland is experiencing rapid economic growth in many sectors such as finance, tech and especially tourism, which has caused a big demand for high quality sand, especially in beach nourishment.
What is the direction of prevailing winds on the Mangawhai-Pakiri coastline?
Easterly prevailing winds.
What sort of a system is the Mangawhai-Pakiri coastline, and what does this mean?
This coastline is largely a closed system, which means that no sediment moves in or out of the system, with the small amount lost from erosion essentially matching the small amount gained from winds and currents.
How much sand is it estimated the Mangawhai-Pakiri coastline recieves every year, and what is this amount in relation to the current mined amount?
It is estimated the coastline recieves around 8000 cubic metres of sand/year, which amounts to less than 1/5 of sand mined today, (102,000m^3/year)
How much sand is it estimated the system at Mangawhai-Pakiri loses naturally?
It is estimated the coastline loses around 7000m^3/year of sand naturally, which in relation to the 8000m^3/year it is estimated to gain makes sand essentially a non renewable resource.
How much sand is mined at the Mangawhai-Pakiri beach annually?
103,000m^3/year is taken against a permit of 165,000m^3/year.
How does the extraction of sand affect the beach?
The extraction of sand en-masse from a beach like this damages its ability to recover and repair itself from storm events and erosion in general, resulting in permanent costal retreat.
Why is the sand at Mangawhai-Pakiri considered unsustainable?
In general, the sand at Mangawhai-Pakiri is considered non renewable, as it has minimal sand inputs, resulting in the extraction being 5x higher than the inputs.
