Chapter 15
LAND-COVER CATEGORIES VERSUS
BIOPHYSICAL ATTRIBUTES TO MONITOR
LAND-COVER CHANGE BY REMOTE SENSING
E. Lambin
Département de Géographie, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
1.
INTRODUCTION
The objective of this commentary is to discuss methodological issues
related to the monitoring of land-cover changes by remote sensing. The main
emphasis is on the complex nature of land-cover change processes and on
the requirement to adopt a continuous representation of the land surface
attributes rather than a discrete representation of land cover categories, in
order to grasp this complexity. This implies the further development of
model inversion approaches to derive biophysical variables of the surface in
a spatially explicit and temporally continuous ways. Improving the accuracy
of the remote sensing-based methods currently used to derive these variables
is viewed as a research priority to allow the scientific community to better
measure, and therefore understand, processes of land-cover changes.
One generally distinguishes between land-cover conversion—the
complete replacement of one cover type by another, and land-cover
modification—the more subtle changes that affect the character of the land
cover without changing its overall classification (Turner et al., 1993). Land
cover modifications may result in degraded ecosystems, and are generally
more prevalent than land-cover conversions. In principle, the monitoring of
land-cover conversions (e.g., agricultural expansion or deforestation) can be
performed by a simple comparison of successive land cover maps (e.g.,
derived by classification of remote sensing data or by field surveying).
137
M.M. Verstraete et al. (eds.), Observing Land from Space: Science, Customers and Technology, 137–142.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.
LAND-COVER CATEGORIES VERSUS
BIOPHYSICAL ATTRIBUTES TO MONITOR
LAND-COVER CHANGE BY REMOTE SENSING
E. Lambin
Département de Géographie, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
1.
INTRODUCTION
The objective of this commentary is to discuss methodological issues
related to the monitoring of land-cover changes by remote sensing. The main
emphasis is on the complex nature of land-cover change processes and on
the requirement to adopt a continuous representation of the land surface
attributes rather than a discrete representation of land cover categories, in
order to grasp this complexity. This implies the further development of
model inversion approaches to derive biophysical variables of the surface in
a spatially explicit and temporally continuous ways. Improving the accuracy
of the remote sensing-based methods currently used to derive these variables
is viewed as a research priority to allow the scientific community to better
measure, and therefore understand, processes of land-cover changes.
One generally distinguishes between land-cover conversion—the
complete replacement of one cover type by another, and land-cover
modification—the more subtle changes that affect the character of the land
cover without changing its overall classification (Turner et al., 1993). Land
cover modifications may result in degraded ecosystems, and are generally
more prevalent than land-cover conversions. In principle, the monitoring of
land-cover conversions (e.g., agricultural expansion or deforestation) can be
performed by a simple comparison of successive land cover maps (e.g.,
derived by classification of remote sensing data or by field surveying).
137
M.M. Verstraete et al. (eds.), Observing Land from Space: Science, Customers and Technology, 137–142.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.