|
Landslide Assessment & Prevention of Future Risks
Monts BAMBOUTOS, CAMEROON
The region around the town of BAMENKA
The LANDSAT-5 TM and LANDSAT-7 ETM+ images, subsets of which are shown below,
have been acquired in 1988 and 2002, respectively (Courtesy of the University of
Maryland, Global Land Cover Facility).
These images have been processed to improve their spatial resolution to 15
meters x 15 meters.
In the 1988 image, forest (in green tones) was still covering half of the area
shown (6.5 x 5.5 kilometers), around the - then - village of Bamenka.
In May 2002, the number of small bright points corresponding to the
individual houses has considerably increased, which means that the population
has increased in the same proportion. Bamenka became a town.
It can be observed that the forest (green tones) has regressed considerably as
the population grew. Forest has also regressed on the interior slopes of the old
caldera.
Roads are much better visible, and are more numerous. Also the amount of bare
soils (in violet), principally around the housing areas has increased.
All these factors together have dramatically raised the risk of landslides, and
the points from where a landslide is likely to depart are indicated at the
center of the red boxes.
These images have been orthorectified and radiometrically corrected using the Digital Elevation Model built using the RADARSAT-1 and ERS-1 SAR images.
The region around the town of DJUTTITSA
The LANDSAT-5 TM and LANDSAT-7 ETM+ images subsets of which are shown below,
(covering 8.3 x 6.5 kilometers) have been acquired in 1988 and 2002,
respectively. The area shown is very close to the preceding one (Bamenka). These
images have been processed to improve their spatial resolution to 15 meters x 15
meters.
In the 1988 image, forest (in green tones) was still covering the interior of
the caldera, as well as most of its outer slopes, north of the village of
Djuttitsa. Forest covered all the valleys going down the outer slopes of the
caldera.
In 2002, dense alignments of houses along the roads are visible, clearly an
indication that the population has grown considerably in the meanwhile.
Deforestation has strongly affected the inner part of the caldera, where less
than half of the forest still remains.
In most of the valleys descending the outer slopes of the caldera in the
direction of Djuttitsa, forest has been depleted. Bare soils within and
around the housing areas have also grown in importance.
This evolution of the landscape has lead to a situation where the threat of
landslides becomes the reality. The points from where a landslide is likely to
happen, possibly in the direction of housing areas are indicated in the middle
of the red boxes.
These images have been orthorectified and radiometrically corrected using the Digital Elevation Model built using the RADARSAT-1 and ERS-1 SAR images.
Produced by PARBLEU TECHNOLOGIES Inc.
|
|
Operational partners of PARBLEU TECHNOLOGIES Inc. :
|
|
|
|
| Privateers NV | Treemail | AP Formation | db-Online |
Copyright (C) PARBLEU Technologies Inc., 2004