Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Pauatahanui inlet: effects of historical catchment landcover changes on inlet sedimentation. Technical Report

Author
Swales, A., Bentley, S.I., McGlone, M.S., Ovenden, R., Hermanspahn, N., Budd, R., Hill, A., Pickmere, S., Haskew, R. and Okey, M.J.
Year
2005
Journal / Source
Report prepared for Greater Wellington Regional Council and Porirua City Council. NIWA Client Report HAM2004-149.
Keywords
Pauatahanui, sediments, historical, core samples, sedimentation rates, estuary, estuarine, heavy metals, contaminants
Summary
As part of a GWRC-PCC environmental programme, NIWA was commissioned to reconstruct the sedimentation history of the Pauatahanui inlet and relate this to landcover changes during the last 150 years. The reconstruction was based on radioisotope and pollen dating and analysis of sediment cores. The specific objectives of the study are to: (1) quantify changes in sediment accumulation rates (SAR) due to deforestation and subsequent conversion to pasture and the effects of urban development since the 1960’s; (2) spatial variations in SAR, particle size and heavy metal profiles between urban and rural sub-catchment outlets and the central mud basin (CMB); (3) relate observed sediment profiles to landcover history; (4) reconstruct ~annual SAR time series where suitable data are available; and (5) provide an assessment of potential future SAR over the next 50 years based on present-day landcover and land management practices.