mapping of african tulip with worldview-2 image...

Mapping of African

Tulip

with WorldView-2

Image Data

Litia Gaunavou

Wolf Forstreuter

African tulip

Spathodea campanulata

History and Problem

• Imported as ornamental tree

• Grows in abandoned farms

• Grows in forest openings

• Competition to local species

• Very light wood not usable ?

• Not mapped in Fiji

Mapping Purpose

1. Indicator for forest degradation

2. Eltech Fiji Limited utilises the

timber for energy production

Flowering Season

August - November

African Tulip Grows in Groups

Mapping scale 1:10,000 required

Natural Colour

Bands: 5,3,2 Enhanced

Absorption and Reflection of

Leaves

1 green light

2 blue light and

red light

3 near infrared

Bands: 7,5,3 Enhanced

Infra - Red

Image Capture

• July - November too short to get

cloud free images

• Spectral signature of leave

reflection must be investigated

WorldView-2 Image

Normal view (Google Earth)

Landsat Image Data

WorldView-2 Image

Natural colour combination enhanced

WoldView-2 Image

False colour IR combination,

African tulip is visible

Target: Spectral Signatures

-200

0

200

400

600

800

1000

1200

1400

1 2 3 4 5 6 7 8

W

a

v

e

l

e

n

g

t

h

s

WorldView 2 Bands

AfricanTulip

Forest

Spectral Signatures African Tulip & other Forest

WorldView-2 Bands

Re

fle

cta

nc

e

Classification of Test Areas

Data AfricanTul AfricanTul Forest1 Forest2 Forest3

AfricanTul 100.00 3.57 0.39 0.48 0.34

AfricanTul 0.00 85.71 1.52 1.83 2.90

Forest1 0.00 0.00 57.92 18.42 13.21

Forest2 0.00 7.14 23.60 60.91 17.73

Forest3 0.00 3.57 16.57 18.36 65.81

Summary

• Mapping of African tulip is

possible also outside the

flowering season

• Mapping requires image data for

1:10,000 scale

• Mapping requires image

enhancement not possible with

Google Earth screen dumps!

Thanks …