Factors that influence geological hazards

The factors that influence the geological hazards are as follows:

a. Primary Structure

Primary structure includes ripple-mark, cross breeding and flute causes.

Ripple marks are minute undulations formed on rocks due to wave action. Cross breeding are slightly obliquely planes to the major breeding planes. Flute casts are groove in cross breeding. The presence of these structures may affect the behavior of bedding surface due to their roughness and waviness by increasing the shear resistance or the strength of slipping through bedding plane. The nature, orientation and extent of bedding plane highly determine the stability of stratified rocks.

b. secondary structure:

They include folds, faults, joints, thrust and cleavage.

i. fold: a fold is a non-planer configuration resulting from deformation. Fold forming rocks being highly stressed are not considerably stable.

ii. fault: they are raptures along with the opposite walls have moved pass each other . extending and shortening of rock layer informs unstable condition. So, faulted areas are hazardous in nature.

iii. thrusts : low angle reverse faults are called thrusts. Due to activeness of the Himalayan frontal thrust and the main boundary thrust, the entire are is seismically active.

c. Vulnerable Slope:

the angle made by a plane or a line with horizontal plane or line is called vulnerable slope. Slope highly controls the number, size and nature of landslide. Slope angles less than 25 degree are considered as stable slopes. Topping and wedge failure are significant in steep slopes. Plane failure will occur if value of rock slope is less than a hill slope.