sand mining at mangawhai - pakiri coast, new Zealand

Question 1

what case study

Answer 1

sand mining mangamnet along mangawhai - pakiri coastline
-negative effects of human impact

Question 2

Economic development

Answer 2

-sand is a minrel resource aiding with construction, glass making and beach replenishment
-high quality sand located 50km north of Auckland

Question 3

why is Auckland important?

Answer 3

-1.5mil population 1/3rd population
- 35% of NZ GDP
-2.3 mil tourists in 2015

Question 4

offshore mining and sediment budget

Answer 4

-nearshore sand drenching on 20km long coatsline between MandP oprated for over 70 years

Question 5

extraction rate per year

Answer 5

75,000m/3 per year

Question 6

used for?

Answer 6

replenish tourist beached in Auckland

Question 7

renewable or non?

Answer 7

non renewable, derived from offshore sources and the coastal sediment budget is a closed system.

-extraction rates exceed inputs by 5 times

Question 8

impacts on costal landoforms

Answer 8

-sand extraction sunsutanible at current rate
- beaches wider and flatter
-don’t absorbe wave energy as-well - increased erosion - dunes and spits become venerable
-fordune ridges undercut creating steep facing scraps that are venerable to wind erosion.

Question 9

storm of 1978 impact

Answer 9

28m breach at the base of M spit leading the harbour venerable to flooding

Question 10

what are they doing about it?

Answer 10

drenching and creation of gryones restored some equilibrium

Question 11

conclusions

Answer 11

increased rates of natural erosion due to natural protection from storm events
-costal retrete already evident
- long term reterte estimented to be 35m by the end of the centrey.