Mangawhai-Pakiri Coastline

Question 1

How long is the Mangawhai-Pakiri coastline?

Answer 1

20km

Question 2

Sand can be used…

Answer 2

…to make glass, to replenish beaches, to make concrete (etc.), as well as other constructional uses

Question 3

The sand on the Mangawhai-Pakiri coastline is…

Answer 3

…high quality and therefore suitable for construction

Question 4

Tourism on Mangawhai-Pakiri coastline

Answer 4

2.3 million foreign visitors in 2015; over 1 billion USD made from this industry since 2004

Question 5

Auckland

Answer 5

50km south of the Mangawhai-Pakirii coastline, so accounts for 1.5 million people (1/3 of population) and 35% of New Zealand GDP

Question 6

Sediment budget on the Mangawhai-Pakiri coastline

Answer 6

• 165,000 m³/year of sand extracted from this coastline between 1994 and 2004; now 75,000 m³/year of sand extracted from Pakiri beach until 2020 (Mining ended on Mangawhai beach); most of this sand is used for replenishing tourist beaches in and around Auckland
• Most sand in the area thought to have been derived from offshore, therefore not much of the sand that is being removed from the beaches is being re-deposited- 5 times more sand being taken that deposited

Question 7

Impacts of sand mining on coastal landforms (e.g. Mangawhai-Pakiri coastline)

Answer 7

• Beaches have become wider and flatter due to the removal of sediment- they are now much less effective at absorbing waves
• Landforms such as dunes and spits have become more vulnerable due to higher energy waves being able to further erode beaches