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Landslide Hazards in California Coast Ranges (Research Paper))

Introduction

Landslide hazards refer to the possibility for an incident of a harmful landslide within an attacked area. The damage could include loss of life, personal injury, house and building damage, social and economic disruption, and environmental degradation. In the United States, landslide hazards cause “approximately $1 billion - $3.5 billion in damage, and kill between 25 and 50 people” annually (National Research Council, 2004). An area that is confronted with landslide hazards is the state of California, especially in the coastal ranges. Some evidence shows that landslides have occurred for decades. On March 4, 1995, La Conchita, a coastal town in Southern California, experienced a heavy rain season and “600,000 tons of mud” moved down on the town. Fortunately, nobody was hurt but nine homes were buried (Jibson, 2005). Ten years later, on January 10, 2005, La Conchita encountered a mudslide again caused by a winter rainstorm. At that time, “10 people were killed, 13 homes were destroyed, and 23 homes were buried under mud debris” (Rising, 2006). This poor disaster happened again when a second winter rainstorm came through the first day of this year. The rainstorm attacked coastal towns not only in Southern California, but in Northern California also. Floodwaters and mud were sent into the cities. Many homes were covered with mud and streets and highways were shut down (Justin, 2006). The county officials advised homeowners to move out of these areas however some homeowners refused to leave their towns and called for the local counties to be responsible. Landslide hazards can occur in almost any country in the world as long as there are high mountains and hills in their areas. We have to loose many people and waste a lot of money to repair damages due to landslides. To deal with landslide hazard, we should focus on the prevention of landslide hazard. We should study the causes and consequences of landslide hazards and urge the government to institute mitigation strategies preparing for the next situation.

Argument Essay

First, we should study the causes of landslide to relieve damages. We should know that our areas are located in risk areas or not, because the most important factor that causes landslides are geological factors. In areas that contain mountains with weak or sensitive parent materials or weathered materials such as sandstone, or marine sediment, landslides can occur easily. Mudslides that occur in California are often due to this reason. Mudslide will occur when soil consists of “at least 50 percent sand, silt, and clay particles” and is soaked enough to flow rapidly (Highland, 2002). For example, the California coastal ranges include many smaller chains of mountain ranges and consist of hills, ridges, and peaks (The Geograpy of California, 2006). The Northern Coast Ranges consist of two parallel belts of mountains. The Southern Coast Ranges are a group of mountain ranges in Central California. Almost all parent materials of these mountains in these two sites consist of sandstones, siltstones, and soft marine sediment (Coast Ranges, 2006). The mountain ranges are very poorly solidified so that landslide activities can occur easily when there are rainstorms. The people who live in these kind of areas should decide if they can endure this severe risk. If the residents don’t want to beat risk, they should move out. But if they insist that they have to stay there, they should prepare themselves for unexpected landslide hazards by watching weather forecast, building guard walls , or lifting the house’s floors. The residents should not place their hopes only on the officials.

Another factor is morphological factors that are involve with topography or natural activities, for instance, fluvial, wave, or glacial erosion of slope toe or lateral margins, deposition loading slope or its crest, and eliminated vegetation (by fire or drought) areas.

The last factors are human causes such as deforestation, mining, irrigation, etc. We have to cut many trees that causes widely abandoned land due to these activities. As we use land, we should sustain it at the same time. We should avoid land use in high slope area or if necessary, we should build ridges by planting a row of elephant grass in steps to reduce soil erosion. Another suggestion is using a portion of the land and keeping the large trees or using land and conserving the entire forest, for example, forstry agriculture. According to Chowdhury (1999), when there is rainfall for long periods, forestry landslides are produced more than usual. If we live in the effected areas for landsliding, planting trees around hillsides is the best suggestion. Trees make soil aggregation that form strong materials. When there are rainstorms, tree’s roots can absorb water and hold soil surface that can decrease the amount of water and mud before they flow down onto towns.

Secondly, we should study the effects of landslide hazards to look for ways to prevent damages. Landslides impact people, their homes, industries, and transportations systems (e.g., streets, highways). However, not many people concern about these problems. Actually landslide disasters are as important as social and economic problems. They have many effects to social and economic growth. For example, reduced the real estate values in the threatened areas, loss of tax revenues, interrupted transport systems, destroyed agriculture and industrial productivities, the loss of people because of death, injury, or disease, and costs of measures to prevent landslide activity. According to National Research Council (2004), in 1979-1980, the six counties of California lost “approximately $500 million” due to landslides caused by heavy winter rainstorm. In 1982, San Francisco Bay area was damaged with “about 6,500 homes and 1,000 businesses” destroyed. The city and county officials paid for direct costs in “the amount of more than $66 million, and paid $298 million for 930 lawsuits and claims”. Landslides also affect subaerial and submarine landscapes, natural forest and grassland, river quality, the habitats of native fauna and birds, and other animals that live in underground burrow. In fluvial-lacustrine sediments along the Columbia River, landslides cause enormous loss of nesting cliff swallows, as well as impacting anadromous fish (e.g., salmon). Because of increasing sediments in spawning gravels or pools, fish cannot return to spawn in freshwater streams (National Research Council, 2004).

After landslides occur, the results are flooding and mud-covering. State governments and local officials should build channels to drain flood waters and prepare bulldozers to evacuate mud. We should also arrange medical emergency plans consisting of medicines, doctors, and medical instruments for disease and injury that are effects in people from flooding and mud debris. According to the examples, we can infer that landslide hazards involve our entire life cycle. We should not overlook this problem. We should learn from these wrong experiences, solve them and seek a way to prevent these mistakes, not allowing them to happen again.

Finally, we should urge the government to draft the mitigation approaches for the next situation. These three strategies should be provided. First, the government should develop tools for assessing and monitoring the effects of landslide hazards. At present, the evolution of technologies can assist us in predicting situations that will occur in future. The new technologies that we should use for landslide hazard protection are remote-sensing and the geographic information system (GIS). Remote-sensing is used in broadcasting including aerial photography and imagery from airbone satellites (National Research Council, 2004). Remote-sensing images provide region data for indicating the suitability of regional factors such as slope, covered-vegetation and topography that are related to landslides and input attributed data such as precipitation quantity in GIS. GIS will comply statistics and monitor the risk areas. The outputs that we get from these processes are maps that relate to landslide hazards. We should link landslide hazard mapping to land-use planning because human activities are one major cause of landslides.

Next, the goverment should collect and transfer all information to local areas and educate the state and county officials in how to use the information and then the local officials should provide landslide loss and risk information to residents in these areas. The officials should organize some technological trainings that residents in risk area can use for searching for more information about landslides in their areas.

Then we should provide landslide insurance. In New Zealand, a government organization, The New Zealand Earthquake Commission, provides property damage insurance for earthquakes, volcanic eruptions, natural landslide, tsunamis, and hydrothermal activities (National Research Council, 2004). Additional advice is that the government should take care not only of physical aspects of the residents but also mental aspects, too. Giving money to disaster victims is one way that can help these victims, but I think giving them information and protecting policies would help them feel better.

Conclusion

Landslide hazards relate to our lives and can be included by human activities, which result in loss of life or injury, damage house and buildings, and can cause social and economic disruption. We should focus on prevention of landslide hazard by learning about causes and consequences of landslides – when landslide can occur and how to prepare ourselves to deal with landslide hazards. Urging the government to pay more attention to landslide hazards by supporting monitoring technique research, improving laboratories, developing advance procedures and guidelines, and providing education and mitigation strategies would be a great sort.



References

Chowdhury, R. (1999). Landslides. Rotterdam, Natherlands: A.A. Balkema.

Coast Ranges (2006). [Online encyclopedia]. Retrived June 10, 2006, from : http://www.answers.com/topic/coast-ranges.

Highland, L. (2002). Landslide Types and Processes. [U.S. Geological Survey : science for a chanding world]. Retrieved June 9, 2006, from : http://pubs.usgs.gov/fs/2002/3072/.

Jibson, R.W. (2005). Landslide Hazards at La Conchita, California. [U.S. Geological Survey: science for a changing world]. Retrieved June 9, 2006, from : http://purl.access.gpo.gov/GPO/LPS60754.

National Research Council. (2004). Partnerships for Reducing Landslide Risk. Washington, D.C.: The National Academies Press.

Norton, J.S. (2006, January 1). Flood waters begin to recede as residents shift to cleanup. Associated Press. Retrieved from Lexis-Nexis database, May 30,2006.

Rising, G. (2006,January 8). California coastal town fears replay of mudslide that killed 10 people. Associated Press. Retrieved from Lexis-Nexis database, May 31,2006.

The Geography of California (January 16, 2006). [Online map]. Retrieved June 10, 2006, from : http://www.netstate.com/states/geography/ca_geography.htm.

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