Los Angeles Against the Mountains by John Mcpee - Article Example

The phenomenon is fueled by heavy rain which washes material from a slope or when it sheets off of a freshly burned stretch of land. It then acts off as a lubricant for the debris so much so as the rapidly moving water cascades down the slopes, and into the canyons and valleys below. As the system gradually picks up speed, the flow takes on the characteristics of a basic river system. The faster the water flow, the more the water can pick up. As the water picks up more mud and rocks, it begins to resemble a fast "flowing river of concrete".

There have been many measures undertaken to try to control the debris flow and McPhee includes them in the story. Some of them are measures that are reactive such as building barricades or deflection walls out of sandbags or concrete. These methods sometimes are effective and can redirect the flow to prevent the damage to the property but then again, one can never be sure how long they will last with the uncertainty associated with the momentum of the debris flow. There is also the question of where it gets redirected.

Some, as Glencoe Heights residents Lukehart and McCafferty would build ditches that would stem the flow but then again it could not stem the torrent of rain and debris (McPhee, pp.190-191).Providing catch basins which McPhee counted as at least a hundred and twenty bowl shaped excavations are also being employed. The principle is the same as the one governing the ditch where the flow can be stopped by making it fill the basin thereby slowly dissipating its momentum. Such measures are effective only to the point where it can guarantee that it can accommodate the volume and the speed of the flow.

They do take up prime real estate and some would not want their landscape be full of pot holes and the likes. Some catch basins have been constructed to "catch" the debris. Some basins have special overflow ducts with screens to remove the water from the flow and allow more room for the bigger items that may be washed in and take up needed space. The funny thing is, there have been many warnings from scientists especially hydrologists and geotechnical engineers but then again people would prefer the pleasure derived from the scenery and pay for ineffectual defenses than just back away.

The problem presents a positive feedback because as more people demands for the pleasure, the more the mountains are being deforested and redefined.Conclusion Debris flow is an event that is costing the residents of Los Angeles. While there have been many methods already employed, the problem still remains as humans continue to expect that modifying their environment would have little negative effects. Maybe its time that we heed the warnings and just leave nature to its course if only for that particular area.