Spatial and temporal Spatial and temporal changes in Namaqualand - - PowerPoint PPT Presentation

Ravi Ravi Kum ar Kum ar Vadapalli Vadapalli, Richard Knight & , Richard Knight & Eugene Moll Eugene Moll

Spatial and temporal Spatial and temporal changes in changes in Namaqualand Namaqualand: :

Separating out climate from Separating out climate from human human-

• induced changes

induced changes

INTRODUCTION & BACKGROUND INTRODUCTION & BACKGROUND Vegetation change using remote Vegetation change using remote-

• sensing is

sensing is based on based on

• Reflectance (

Reflectance ( Greeness Greeness) )

< < Unhealthy < < Unhealthy Healthy > > Healthy > > < < Low Cover NDVI < < Low Cover NDVI High Cover > > High Cover > >

• Canopy Fragmentation

Canopy Fragmentation

• Replacement

Replacement

• f palatable
• f palatable

with with unpalatable unpalatable spp spp. .

• Alteration in

Alteration in Seasonal Seasonal Change Change Degradation in Succulent Degradation in Succulent Karoo Karoo??? ??? X Change in X Change in amount of Green amount of Green Vegetation Vegetation X Fragmentation in X Fragmentation in Canopy Cover Canopy Cover

Tim e Tim e Series Series

METHODS METHODS

Springbok Springbok Garies Garies Vanrhynsdorp Vanrhynsdorp

• SKEP planning

SKEP planning domain domain

• Time Series

Time Series Analysis (April Analysis (April 1998 1998-

• Feb 2003)

Feb 2003) tri tri-

• monthly

monthly

• SPOT VGT

SPOT VGT Imagery 1 km x 1 Imagery 1 km x 1 km NDVI km NDVI

• Standardized PCA

Standardized PCA

METHODS METHODS SPOT VGT Data SPOT VGT Data

• April 1998

April 1998-

• Feb 2003

Feb 2003 (after that the sensor (after that the sensor was re was re-

• calibrated)

calibrated)

• Imaging integrated for 10

Imaging integrated for 10 day periods day periods – – 177 177 images images

• NDVI calculated

NDVI calculated

Principle Components Principle Components

• Reduce our 177 images into

Reduce our 177 images into fewer independent fewer independent “ “views views” ”

• Analogous to identifying what

Analogous to identifying what

• bjects are by slicing various
• bjects are by slicing various

sections, e.g. What fruit is this? sections, e.g. What fruit is this? Banana Banana C1 C3 C2

Geographical Geographical Seasonal Seasonal Anom alies Anom alies

Components Components

1 1 -

• 78.7%

78.7% 2 2 -

• 6.7%

6.7% 3 3 -

• 2.6%

2.6%

• Component Loadings

Component Loadings (correlation between (correlation between

• riginal S10 data and
• riginal S10 data and

each component) each component) plotted plotted

• Component Graphs

Component Graphs compared to expected compared to expected graphs graphs

RESULTS RESULTS – – Rainfall Rainfall

20 40 60 80 100 120 140 JAN 1998 JAN 1999 JAN 2000 JAN 2001 JAN 2002 JAN 2003

Year Rainfall (mm)

GARIES KAMIESKROON SPRINGBOK STEINKOPF

RESULTS RESULTS – – Component Loading 1 Component Loading 1

Apr'98 Apr'99 Apr'00 Apr'01 Apr'02 Jan'03

0.2 0.4 0.6 0.8 1 1.2

Component Loadings

Geographical Geographical Features Features 98% explained 98% explained

Extended Dry Period 7 8 .7 %

Mining Mining Agriculture Agriculture

RESULTS RESULTS – – Component Loading 2 Component Loading 2

Apr'98 Apr'99 Apr'00 Apr'01 Apr'02 Jan'03

• 0.6
• 0.4
• 0.2

0.2 0.4 0.6 0.8 1

C om ponent Loadings

Perm anent Perm anent Agriculture Agriculture W inter W inter Rainfall Rainfall Sum m er Sum m er Rainfall Rainfall

Seasonal Seasonal Effects Effects

RESULTS RESULTS – – Component Loading 3 Component Loading 3

Apr'98 Apr'99 Apr'00 Apr'01 Apr'02 Jan'03

• 0.6
• 0.5
• 0.4
• 0.3
• 0.2
• 0.1

0.1 0.2 0.3

Com ponent Loadings

Major Climate Major Climate Anomalies Anomalies – – Rainfall / Rainfall / Drought events Drought events

Mining Mining Agriculture Agriculture

• Component 1

Component 1

• Graph: Show two

Graph: Show two “ “crashes crashes” ” in in Greeness Greeness values values

• Map: Identified Mining & Permanent Agric. impacts

Map: Identified Mining & Permanent Agric. impacts

• Component 2

Component 2

• Graph: Annual cycles of

Graph: Annual cycles of Greeness Greeness

• Map: Winter/Summer rainfall divide

Map: Winter/Summer rainfall divide

• Component 3

Component 3 Graph: One extreme Graph: One extreme “ “Crash Crash” ” in Greeness in Greeness Map: Areas Map: Areas “ “independent independent” ” of Greeness

• f Greeness “

“crash crash” ”

DISCUSSION DISCUSSION

Vegetation is stress-sensitive Climate Regimes Discernable Droughts identifiable

ACKNOWLEDGEMENTS ACKNOWLEDGEMENTS

MAPOSDA Project (EU) MAPOSDA Project (EU) VITO for SPOT imagery VITO for SPOT imagery