Natural Hazards and Effects on San Diego California

Introduction

The Geographical region that has the most interest to me is that of Southern California in the United States of America. Southern California, in particular San Diego has always been one of the most desirable areas in California to live creating a very densely populated city. The direct access to both the Pacific Ocean and multiple mountain ranges makes it susceptible to massive wildfires during the long and extremely dry summer months and floods during the winter months. Also contributing to other possible natural disasters, San Diego is located near the San Andres Fault, which runs through California making this city another prime location for earthquakes and its catastrophic damage. In recent years, both the federal and local governments have recognized that San Diego is most likely to be susceptible to wildfires and have implemented new building codes for infrastructures and massive purchases of fire fighting equipment to help combat these disasters and there effects.

The objective of my paper is to explain why San Diego is prone to having natural disasters, what some of these disasters are, and how we can prevent them. Furthermore I will discuss and indentify the primary and secondary effects associated with these specific natural disasters, and there related frequency-and magnitude.

Literature Review

Much of the related information has been obtained through consulting the relevant scientific literature. Works from published journals, periodicals and the use of e-journals contributed too much of the research. All of the related articles have a professional scope and have been published in scientific journals or books. Also contributing to my research was the use of federal and local government web pages. All data presented is subjected to a (+/-) 3% margin of error.

Results

Throughout the late summer months San Diego and its outlying areas become a ticking time bomb for wildfires, many of these disastrous fires are caused by one thing, lack of rain. Because San Diego gets minimal to no rain during its long summer months, the dry brush that takes over many parts of the San Diego mountain ranges know as the "chaparral" becomes very susceptible to ignition. Anything from campers to a careless cigarette butt being thrown from a car window have been known to start massive infernos. Another contributing factor to these massive wildfires are the Santa Anna winds, which according to (United States Geology Survey) are classified as strong extremely dry offshore winds that typically sweep through the Southern regions of California and the Northern regions of Baja California, Mexico , creating the perfect accelerant for massive wildfires.

During the first few days of October 2007, massive wildfires broke out along the Mexican border stretching to Santa Barbara County creating one of the biggest and most destructive wildfires known to the United States. According to (fema.gov) over 200,000 houses were destroyed and 500,000 acres or (2,000km2) of forest lost. A staggering 550,000 people from at least 340,000 houses were under mandatory evacuation (fema.gov). The Risk Assessment Matrix, refer to (Appendix A), will analyze the likelihood and probability of a Wildfire occurring in San Diego County in the next 5 years. According to (Bennett &Estall 1991) when disturbance is infrequent, average parameters can be hard to define as the frequency of the disturbance is of the same order of magnitude. As changes in the casual factors such as fluctuations and long-term trends in climate and human impacts.

There are many side effects to wildfires, because of the massive amounts of land they consume. The primary effected area is the housing industry and the loss of infrastructure. As stated above over 200,000 houses were destroyed during the wildfires in 2007. According to (californiagreensolutions.com) between (1990-2006) wildfires accounted for $4.73 billion dollars in damages. Attached to (Appendix A #2) are my personal photos of some of the devastation the wildfires of 2007 created. Furthermore the loss of forest (i.e.) timber and native species such as plants and animals are also greatly affected.

Much of the secondary effects are far more pervasive than the primary effects. Secondary effects include respiration problems from the plumes of smoke, land slides from soil erosion, and economic losses. As the fires burn large plumes of smoke begin to saturate the air and make the quality of air very poor for breathing. According to (usgs.gov) over 70% of people were affected by respiratory problems from poor air quality in and around the San Diego area during the 2007 wildfires. Another secondary impact of wildfires is soil erosion. Soil erosion occurs when the land is depleted of valuable nutrients making it susceptible to landslides and mudslides in the wet seasons.

Another potentially disastrous hazard San Diego is susceptible to is earthquakes. Much of Los Angeles county and the lower lying San Diego county run along major fault lines like the San Andres to the north which runs parallel all the way down to Baja California, Mexico. The largest of the faults, and presumed to be the most active, are the Rogers Creek-Hayward, Green Valley-Concord, and Calaveras which are all within 200 miles of San Diego county. According to (Bennett& Estall 1991) the infamous San Andres fault in California lies within a highly active tectonic zone that forms the boundary between the Pacific and North American plates. Both of these plates are