Debris Case Study

The San Gabriels are at the stage of tectonic youth and it is therefore rising in a quick pace. Angle of repose refers to the maximum angle that a material could stay on the surface without slipping. The ‘loose inimical’ slopes of San Gabriel ‘flout the tolerance’ of the angle of repose. Located near the city of Los Angeles and ten thousand feets above the sea level, the needs of the people created huge destructions to this place causing consequences.

Debris flow could be thought as a fresh concrete. It is composed of water and solid materials above sand sized. This is what the Genofles encountered on one evening. The house was built with strong concrete and steel reinforcement. This was because Bob genofile was a general contractor with

Debris flow cause more destruction to the infrastructure and buildings than to the lives of people. There are cases where tree trunks moved with the debris flows like javelins and destroyed a gym. People along the mountain front therefore created deflection walls and others in effort to reduce the damage. The ditch was also found very successful at an event.

Debris basin started from an incident when a gravel pit was found very successful in catching debris. Since then the Debris basin, also known as debris dam, was built around important buildings and spots with investment of millions of dollars. Over time the debris basins trapped 20 million tons of mud and rock.

Crib structures were also built to stabilize mountain streambeds and rocks before coming to the debris basins. The San Gabriels Dam was also built to trap large volumes of

So I only included key points about debris flow from now on.

Debris flows do not happen every year. It take time for it to form and the vintage years were 1934, 1938, 1969, and 1978. Also, major flows happened more than once in a decade.

San Gabriels are very steep. It is also cut by the water flow very sharply. In addition, the slopes are very steep with average of 60 to 70%. Therefore, slopes are often larger than the angle of repose. This means that a solid may be hard to hold at these angles with just frictional force.

Furthremore, the San Gabriels vegetation is mainly chaparral. Chaparral is a shrubland found at California. It is vulnerable to fire and it rejuvenates as fire nourishes it. The droughts at the region continued for an extensive period and the dead leftovers would not decay but rather just become dry.

During Santa Ana, strong winds cause vegetation to ignite. This makes a huge wild fire. There is a waxy layer at the leaves of chaparral to protect water from heat. When fire happens, this waxy layer becomes gas and then form new and hydrophobic layer at the surface. Then, the following rain caused by the fire create the debris flow of the materials topped over the hydrophobic