The Mangawhai-Pakiri coastline, New Zealand CS

Question 1

Where is the Mangawhai-Pakiri Coastline?

Answer 1

On the east coast of the Northland spit

50km from Auckland, New Zealand

Question 2

Where did the sand come from in the Mangawhai-Pakiri coastline?

Answer 2

As the last ice age ended the sea levels began to rise and they brought the sand from the dunes

All sand within a certain size range was swept towards the land

The sand is relic store and non-renewable

Question 3

What are the 3 economic uses for the Sand?

Answer 3

Construction

Tourism

Beach recharge

Question 4

How is the sand used for construction?

Answer 4

Construction firms sought after 20 year terms to use the sand for construction projects in Auckland due to its high quality

Auckland makes up 35% of New Zealand’s GDP

With a growing population of 1.5 million making the damned even higher

Question 5

How does the sand impact tourism?

Answer 5

Around 2.5 million tourists visited the Auckland coastline

Question 6

How has the sand been used for beach nourishment?

Answer 6

Been used to replenish the beaches at:

Mission bay

Kohimarama

St Heliers

Question 7

Is the Managwhai-pakiri coastline open or closed?

Answer 7

it is at present a closed system meaning that any outputs are not replaced by fluvial inputs or offshore waves

Question 8

3 facts about sand extration at Mangawhai-Pakiri coastline

Answer 8

Sand mining at Pakiri beach took place until 2020

In July 2020, applications to extract 2,000,000m^2 over 20 yrs were submitted

Extraction at Pakiri beach are 5x higher than the inputs

Question 9

How have beaches been impacted by sand mining?

Answer 9

Beaches starved of sediment have become wider and flatter making them worse at absorbing wave energy

Question 10

How are spits impacted by sand mining?

Answer 10

Higher energy waves are able to complete more erosion making spits vulnerable

1978 - 28m breach of Mangawhai spit - impacted harbour