//4.b. Economic development unintentionally causes change within coastal landscape systems

Question 1

Sand mining along the Mangawhai-Pakiri coastline of New Zealand- economic development

Answer 1

• sand is an essential mineral soure- used in construction
• high quality sand resource occurs at Mangawhai-Pakiri. It is suitable for the construction industry
• Auckland region has population of over 1.5 million and is 35% of New Zealand’s GDP
• 2015- 2.3 million foreign visitors

Question 2

Sand mining along the Mangawhai-Pakiri coastline of New Zealand- offshore sand mining and sediment budget

Answer 2

• 70 years of nearshore sand dredging between Mangawhai and Pakiri
• between 1994 and 2004, 165,000m³ a year were extracted
• mining ended in 2005 but continued at Pakiri Beach
• current rates are 75,000m³/year until 2020
• outputs of sand through nearshore mining are not replaced by inputs from rivers and waves offshore
• extraction rates exceed inputs
• effect of mining is to deplete the total sand supply, stored in dunes, beaches and on the sea bed up to 2km offshore

Question 3

Sand mining along the Mangawhai-Pakiri coastline of New Zealand- impact on coastal landforms

Answer 3

• sand extraction are unsustainable
• depletion of sand has an impact on landforms/landscapes
• beaches starved with sediment have become wider, flatter and are less effective om absorbing waves
• higher energy waves erode beaches and landforms
• foredune ridges are undercut by wave action, developing scarps
• loss of vegetation makes them susceptible to wind erosion
• increased rates of coastal erosion means protection from stones
• coastal retreat attribbuted to sand extraction
• flooding threatens the waterfront