Land Use and Climate Influences

on Sediment Transfer, East Coast,

North Island, New Zealand

Noel Trustrum and Mike PageLandcare Research

MARGINS NSF-NEW ZEALAND Workshop 4–9 May 2003

Waipaoa

Discrimination of climatic, tectonic and anthropogenic forcing

Pacific Ocean

Raukumura Range

Raukumura Range

Raukumura Range

Raukumura Range

PovertyBay Flats

Upland Sediment Sources

Waipaoa River Basin

Bankfulldischarge atKanakanaia

Cum

ulat

ive

Perc

ent Su

spen

ded

Sedi

men

t Lo

ad

Discharge (m3 s-1)

100

80

60

40

20

00 1000 2000 3000 4000 5000 6000

Lake Tutira after Cylcone Bola Sediment core with storm sediment layers (grey) and eutrophication layers (black)

5 yr moving average – Lake Tutira, New Zealand

Lake Tutira -Recent cores

Lake Tutira -Recent cores

The Challenge

To link the high resolution Tutira record of Holocene climate variability with other paleoenvironmental data in the Waipaoa Sedimentary System, to construct a chronology of the drivers of sediment generation, and utilising knowledge of process and landscape behaviour, to elucidate Holocene sediment fluxes.

Key questions include:

• how did the landscape respond to these drivers?

• how much sediment was generated?

• to what extent was sediment stored and censored during transport through the fluvial system?

• what component of these fluxes is preserved in the marine record?