Coasts- New Zealand CS Flashcards
Where is the Mangawhai-Pakiri coastline located?
The Mangawhai-Pakiri coastline is located in the North island of New Zealand. Mangawhai is a coastal town, and Pakiri is a region situated to the north of Auckland. On the east coast of New Zealands Northland Peninsula.
What is the economic development of sand mining along the Mangawhai-Pakiri coastline of New Zealand?
-Sand is an essential mineral resource in a modern economy
-Has a wide range of uses including construction, concrete making, glass manufacture and beach replenishment
-A high quality sand resource occurs in the nearshore zone in this location
-This sand is high quality and suitable for the construction industry
-Loacated 50km North of Auckland, it is convenient for NZs largest and economically most dynamic metropolitan region
-Auckland region has a population of over £1.5m and accounts for a third of NZs total population and 35% of the countrys GDP
-The region is rapidly growing and apart from business, finance and tech industry, tourism centered around Auckland coastal amenities is booming and 2015 saw a record of 2.3m foreign visitors
What are the components of offshore sand mining and the sediment budget?
-Nearshore dredging on the 20km long coastline between Mangawhai and Pakiri has operated for over 70 years
-Between 1994 and 2004, 165,000 m cubed per year were extracted
-Although mining ended at Mangawhai in 2005, it continued at Pakiri beach
-Current rates of extraction are 75,000 m cubed per year until 2020
-A large proportion of this sand is used for replenishing Aucklands tourist beaches and in the construction industry with many holiday homes and hitels being built
-Deposited during the Holocene (9000 years ago) sand is a non renewable resource on the Mangawhai-Pakiri coastline
-There are a few sizeable rivers in the area and most sand is thought to have been derived from offshore
-Coastal sediment budget is essentially a closed system
What are the unintentional impacts on the coastal landscape?
-The removal of sand from beaches and dunes can alter sediment dynamics and compromise the stability of coastal landforms (sand mining)
-Climate change (sea level rise)
-Dam construction or water abstraction, can affect sediment transport and nutrient cycling
