Eroding Slopes – Possible Landslide Risk Areas
Yesterday, the Fortnightly Journal got some pictures from concerned citizens of big lalaguna in Barangay Sabang. The Picture are showing, what experts call “Dangerous Clear-cutting in eroded Slopes near Building Structures”, logically, the folks around this area are unhappy to see that something like that still exists in our Town. Clear cutting to such extent can cause dangerous Landslides, in such case, where the area is so close to occupied Buildings, it could even cause the loss of human life’s.
(Picture taken by Rosemarie Dela Torre)
So lets have a look, why so many areas in and around Puerto Galera seem to be so eroded and how a such slopes fail?
The most common failures in slopes of Puerto Galera come from the relatively shallow top soil,which further worsened by the depth of weathering and infiltration during rainstorms situations. Slope can collapse easily by shear if the soil is nearly saturated and high pore pressure can be built up rapidly. The falling debris carried by its potential
and momentum can rush down the slope at very high speed and travel a long distance causing huge damages. Besides, highly decomposed rock in a slope may behave very similar to soil.
Factors affecting the stability of slopes:
1. Topography and its surrounding physical conditions.
Detail analysis can be done by appropriate site investigation process.
2. Geological conditions such as the nature and depth of its subsoil, degree of decomposition, or location
of fracture etc. This data can be obtained by soil investigation.
3. Shear strength of the slope-forming materials. Data can be obtained using appropriate laboratory tests.
4. Surface and ground water condition5. External loading and surcharges, such as from traffic, nearby structures, possible vibration etc.
6. Clear Cutting of the area.
The MENRO office could not be reached for a statement but we certainly hope that our LGU will inspect the area and have a serious talk to the landlord.
One Comment
Sun Tzu
knock, knock, who’s there? nobody’s here. accident waiting to happen.