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Geocarto Tree Monitoring System (GTMS)

Tree Stress Monitoring in Hong Kong

Monitoring tree stress from space using WorldView-2 or WorldView-3 high resolution satellite data

 

 

Time-saving and Cost-effective 

New technology to detect 3 Warning Signs revealed by stressed trees before collapse

New!

We have added the following new charts in the gallery demonstrating our study on stressed trees.

 

Chart 17   Tree in Good Condition
Chart 18   Contrast between Two Trees

Chart 19   What do stressed trees reveal before collapse?
Chart 20   Monitoring Tree Health with Satellite Data

Chart 21   Spectral Reflectance Reveals Tree Stress

Chart 22   Spectral Reflectance Analysis of a Stressed Tree, 2010-2016

Chart 23   Reflectance Analysis Reveals Warning Signs

Chart 24   Warning Signs Revealed by a Stressed Tree

Chart 25   Changes in the Health Condition of a Stressed Tree

Chart 26   Deterioration of a Stressed Tree

Chart 27   What do Stressed Trees reveal before Collapse

Chart 28   What do Stressed Trees reveal before Collapse generated with AComp Data

Chart 29   Collapsed tree in Fanling

Chart 30   Collapsed tree in Berlin

Chart 31    Collapsed tree in Cincinnati

Chart 32   Collapsed tree in Chiswick

Chart 33   Collapsed tree in Düsseldorf

Chart 34   Collapsed tree in Maisons-Alfort

Chart 35   Collapsed tree in Singapore

Chart 36   Collapsed tree in Sydney

Chart 37   Collapsed tree in Whittier

Chart 38   Collapsed tree in Vancouver

Chart 39   Collapsed tree in Singapore

Chart 40   Collapsed tree in Singapore

Chart 41   Removed tree in Lei Yue Mun Park

Chart 42   Stonewall Tree in Forbes Street

 

Introducing WorldView-2 & WorldView-3
Providing satellite data to cover the whole HKSAR in a single pass​

(Image Copyright © DigitalGlobe)

Spectral Reflectance Analysis

Detects 3 warning signs revealed by stressed trees before collapse caused by biotic and abiotic factors. The warning signs are (1) drop of NIR-1 and NIR-2 reflectances, (2) shift of red edge band to shorter wavelength and (3) reduced absorption in red band.

Case Studies

All the following trees showed the above 3 warning signs before collapse

Tree on steep slope

Tree on stone wall

Tree on level ground

Case 1 - Tree on steep slope

We studied a stressed tree on a steep slope in Lower Albert Road near former Central Government Offices. It collapsed on 20 July, 2015.

 

The spectral reflectance curves in this case were generated from the WorldView-2 data collected on 25 May, 2010 and 17 April, 2015. All 3 warning signs were revealed before its collapse.

2010

2015

Case 2 - Tree on stone wall

We studied a stressed tree on a stone wall in Bonham Road near Centre Street. It collapsed on 22 July, 2015.

 

The spectral reflectance curves in this case were generated from the WorldView-2 data collected on 25 May, 2010 and 17 April, 2015. All 3 warning signs were revealed before its collapse.

2010

2015

Case 3 - Tree on level ground

We studied a stressed tree on level ground in Bonham Road near King's College. It collapsed on 19 April, 2015.

 

The spectral reflectance curves in this case were generated from the WorldView-2 data collected on 25 May, 2010 and 17 April, 2015. All 3 warning signs were revealed before its collapse.

2010

2015

 

Data Cost

(AComp data and "Lossless" pansharpened data)

Questions

Questions and answers on Tree Stress Study

Thank you for viewing these tree stress study charts.  They are designed to explain the applications of high resolution satellite remote sensing technology in monitoring tree stress in Hong Kong. The following questions cover the main points presented in the charts.  Can you answer these questions?