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
0.000
0.200
0.400
0.600
0.800
1.000
ND
VI cleared_01
forest_01
forest_02
Forest Clear-felling with MERIS Background
0.000
0.200
0.400
0.600
0.800
1.000
ND
VI
dec03_01
dec03_02
dec03_05
dec03_08
dec03_09
dec03_10
Jan03 to Jan04
Jan03
Jan04
Jan03
Jan04
Image Discontinuity
Discontinuity from Jan04
AOIs generated from forest records
Chosen AOIs
0.000
0.200
0.400
0.600
0.800
1.000
Image date
ND
VI
f04
f06
f08
f09
f10
f11
f14
f18
f20
f21
f27
f28
f29
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