Table Of ContentRadar remote sensing to support
tropical forest management
Promotoren: Dr.ir. R.A. Feddes
Hoogleraar bodemnatuurkunde, agrohydrologie en grondwaterbeheer
Dr.ir. R.A.A. Oldeman
Hoogleraar bosteelt en bosecologie
Co-promotor: Dr.ir. D.H. Hoekman
Universitair hoofddocent bij het departement omgevingswetenschappen
J.J. van der Sanden
Radar remote sensing
to support
tropical forest management
Proefschrift
ter verkrijging van de graad van doctor
op gezag van de rector magnificus
van de Landbouwuniversiteit Wageningen,
Dr. C.M. Karssen,
in het openbaar te verdedigen
op dinsdag 9 december 1997,
des namiddags te 16.00 uur in de Aula
The Tropenbos-Guyana Series publishes results of research projects carried out in the
framework of the Tropenbos-Guyana Programme. The Tropenbos-Guyana Programme operates
within the framework of the international Programme of the Tropenbos Foundation. The multi-
disciplinary Tropenbos-Guyana Programme contributes to conservation and wise utilisation of
forest resources in Guyana by conducting strategic and applied research and upgrading
Guyanese capabilities in the field of forest-related sciences.
J.J. van der Sanden
Radar remote sensing to support tropical forest management
Tropenbos-Guyana Series 5
Tropenbos-Guyana Programme, Georgetown, Guyana
ISBN 90 - 5485 - 778 - 1
Keywords: remote sensing, radar, tropical rain forest, forest resource assessment, forest
resource monitoring, sustainable forest management
© 1997 Tropenbos-Guyana Programme, J.J. van der Sanden
All right reserved. No part of this publication, apart from bibliographic data and brief
quotations in critical reviews, may be reproduced, re-recorded or published in any form
including print, photocopy, microfilm, electronic or electromagnetic record, without written
permission.
Printed by Ponsen & Looijen bv, Wageningen
Cover: C-, L-, P-band colour composite radar image showing the West Pibiri compartment in
Mabura Hill, Guyana. Images acquired by the NASA/JPL AIRSAR system. P-band total power
image shown in red, L-band total power image shown in green and C-band total power image
shown in blue. Image processing by Martin Vissers.
The investigations reported in this text were carried out at the Department of Water
Resources of the Wageningen Agricultural University, with funding from the Netherlands
Remote Sensing Board (BCRS) and within the framework of the Tropenbos-Guyana
Programme.
Department of Water Resources, Wageningen Agricultural University, Nieuwe Kanaal 11,
6709 PA Wageningen, The Netherlands, http://www.slm.wau.nl/whh/rs/ .
Netherlands Remote Sensing Board (BCRS), P.O. Box 5023, 2600 GA Delft, The
Netherlands, http://www.minvenw.nl/rws/mdi/bcrs/en/ .
Tropenbos-Guyana Programme, Lot 12 E Garnettstreet, Campbellville, Georgetown, Guyana,
http://www.tropenbos.nl/ .
Publication was made possible by the financial support of the Tropenbos-Guyana Programme
and the Wageningen Agricultural University.
Abstract
van der Sanden, J.J., 1997. Radar remote sensing to support tropical forest
management. Wageningen, The Netherlands (Wageningen Agricultural University),
Tropenbos-Guyana Series 5, doctoral thesis, 330 p.
This text describes an investigation into the potential of radar remote sensing for
application to tropical forest management. The information content of various radar
images is compared and assessed with regard to the information requirements of
parties involved in tropical forest management at the global, national and local
spatial levels. The study distinguishes between the use of radar remote sensing for
application to forest resource assessment and forest resource monitoring. Both
assessment and monitoring are essential components of procedures for sustainable
forest management. The radar data studied are of tropical forest areas near the
township of Mabura Hill in Guyana and the city of San José del Guaviare in Colombia.
Mabura Hill is comprised of differing intact, primary forest types and forests that have
been subjected to industrial selective logging. San José del Guaviare, on the other
hand, is characterised by the presence of secondary forests and a variety of
non-forest cover types. The available radar data set includes high resolution airborne
radar images with differing wavelengths (i.e. X-, C-, L- and P-band) and polarizations,
time-series images acquired by the first European remote sensing satellite ERS-1 and
a collection of low altitude, nadir-looking, X-band scatterometer measurements.
The study makes use of three fundamentally different information sources from the
radar return signal: its strength or backscatter, polarization and phase, and spatial
variability or texture. Results show that backscatter values computed from L- and
P-band radar data and textural attributes computed from high resolution X- and
C-band radar data make modest to good and complementary bases for region-based
classification of tropical land cover at the level of primary forest types. Textural
attributes and backscatter values computed per region from mono-temporal ERS-1
images make modest bases for classifying at the levels of primary forest, logged-over
forest, secondary forest and non-forest and poor bases for classifying at the level of
primary forest types. Roads are usually the most easily observable indicators of
foregoing and/or forthcoming (selective) logging and other human activities in ERS-1
images. Detection of change in road networks by means of ERS-1 images would
make a good first step in forest resource monitoring at the national spatial level, in
particular. Textural attributes enable the ranking of forest types according to the
degree of canopy roughness. Specific textural attributes also allow for quantification
of canopy architectural properties. Despite differences in measurement scale, the
canopy roughness of the land cover types studied was found to appear similarly in
the texture of the available spaceborne and short wavelength airborne radar images.
Keywords: remote sensing, radar, tropical rain forest, forest resource assessment,
forest resource monitoring, sustainable forest management.
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