Tracking Land cover Change in the Motueka

Catchment Using ENVISAT

David PairmanStephen McNeillHeather NorthStella Belliss

Outline

• Motueka Integrated catchment monitoring project

• Study site and data sources

• Methodology

• Initial results – change detection

• Geolocation problems

• Identifying timing of changes

• Summary

Motueka Integrated Catchment Monitoring Project (ICM)

• Identify and implement sustainable patterns of land, water and coastal use

• Collaboration of research providers, council, community and other interest groups

• Interaction of ecosystem componentsland change → river → costal environment

• Needs information on land cover change.

Motueka catchment

Data used in the study

MERIS quarter scene

• Required orthorectification

• Scene tie points• Modified by

correlation results with ETM image

• Aiming for sub-pixel accuracy

TM and aerial photo runs

Photo interpretation between aerial surveys

Large plot averages

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ND

VI cleared_01

forest_01

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Forest Clear-felling with MERIS Background

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VI

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Jan03 to Jan04

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Jan04

Image Discontinuity

Discontinuity from Jan04

AOIs generated from forest records

Chosen AOIs

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Image date

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VI

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Summary

• 21 MERIS image sequence covering 2 years

• Land cover change has clear spectral differences

• Scale of change is marginal for MERIS scale

• Rectification needs to be more accurate

• Discontinuities observed in level 1P & 2P imagery

• For areas identified as changed - can pick timing using MERIS data with some (limited) success