5.3 Applications in the Landslide Experiments
67
slope. In addition, according to the investigation by the Management Board for
the Middle Reaches of the Yellow River (MBMRYR 1993), the ratios R values
in the Nanxiaohegou Catchment, Lv’ergou Catchment, and Jiuyuangou Catchment
were 58, 68 and 20%, respectively. Results in this study are similar to the research
conclusions mentioned above.
5.3.2 Methods to Obtain Relatively Clear Video
Typically, the topography meter could measure the gravity erosion on the slope with a
gradient of 30°–70°. In the present laboratory condition, the laser projection received
in the camera is very clear. However, on the Loess Plateau of China, some gully banks
are extremely steep, sometimes more than 80°. One method to obtain a relatively
clear video is to rotate the laser source away from the slope, based on the premise of
ensuring the camera sightline remains perpendicular to the laser plane, as shown in
Fig. 5.7. As a result, the slope with projected lasers shown in the camera becomes
relatively gentle so that the best observation effect can be obtained. In Fig. 5.7, the
a
b
c
b
b
Orignal positions of
the laser source and
the camera sightline
Rotating away
from slope
Fig. 5.7 A method to obtain a clear and undistorted video for the very steep slope. The laser source
is rotated away from the slope based on the premise of ensuring that the camera sightline remains
perpendicular to the laser plane
67
slope. In addition, according to the investigation by the Management Board for
the Middle Reaches of the Yellow River (MBMRYR 1993), the ratios R values
in the Nanxiaohegou Catchment, Lv’ergou Catchment, and Jiuyuangou Catchment
were 58, 68 and 20%, respectively. Results in this study are similar to the research
conclusions mentioned above.
5.3.2 Methods to Obtain Relatively Clear Video
Typically, the topography meter could measure the gravity erosion on the slope with a
gradient of 30°–70°. In the present laboratory condition, the laser projection received
in the camera is very clear. However, on the Loess Plateau of China, some gully banks
are extremely steep, sometimes more than 80°. One method to obtain a relatively
clear video is to rotate the laser source away from the slope, based on the premise of
ensuring the camera sightline remains perpendicular to the laser plane, as shown in
Fig. 5.7. As a result, the slope with projected lasers shown in the camera becomes
relatively gentle so that the best observation effect can be obtained. In Fig. 5.7, the
a
b
c
b
b
Orignal positions of
the laser source and
the camera sightline
Rotating away
from slope
Fig. 5.7 A method to obtain a clear and undistorted video for the very steep slope. The laser source
is rotated away from the slope based on the premise of ensuring that the camera sightline remains
perpendicular to the laser plane