When Hillsides Collapse, Disaster Follows
By Gordon Gumpertz
The term "Natural Disaster" leads most people to think first of highly dramatic events such as earthquakes, volcanoes, and tsunamis. But it turns out that landslides and mudslides, though seldom in the headlines, are among the world's most costly natural disasters in lost life and property, and they occur many times a year in most countries around the world.
In 2010 alone, more than 4,000 people lost their lives in landslides in Uganda, Brazil, China, Colombia, Guatemala, Pakistan, Bangladesh, India, Mexico, and other parts of the world. The 2011 list has not yet been compiled, but mudslides took thousands of lives in most of those same countries, plus The Philippines, Japan, and Italy. The costs in property loss, evacuations, and restoration amount to many billions of dollars a year. These landslides followed periods of prolonged or heavy rain that saturated and destabilized the hillside, causing a portion of it to detach and slide. Earthquakes and volcanoes also produce landslides that take lives, but those fatalities are attributed to the major causal event, not to the landslides.
Landslides don't often make the major headlines because the death toll per event is usually in the hundreds instead of the thousands as is often the case in a major earthquake, volcano, or tsunami. And 2010 was not an unusual year in terms of landslide damage. Landslides go on month after month, year after year, wherever and whenever heavy rain penetrates susceptible soil on an incline.
What puts the slide in landslide? There are many underlying causes. Some are natural and some are manmade. Natural hillsides are inherently stable. Some of the things that destabilize them and make them vulnerable to collapse are:
Removal of Vegetation. Vegetation absorbs water and keeps a hillside dry. The root systems tend to strengthen and stabilize the ground. A forest fire caused by lightning would be a natural cause of vegetation removal. Clear-cutting of timber on that slope would be a manmade cause. Both natural and manmade causes weaken the soil and make it susceptible to failure.
Addition of Moisture. Heavy rain or heavy snowfall can put hillsides at risk. Most soils transform into mud when saturated with water. Water infusion also reduces the friction between soil particles. Without enough friction to hold the soil in place, a heavy mass of mud can detach from the hillside and slide to the bottom.
Addition of weight. Heavy rainfall or snowfall is also nature's way of adding weight to a slope. Grading for building pads and adding fill is a manmade way of adding weight. Both can contribute to a landslide when other factors are in place.
Other Human Factors. Road building on a slope, and cultivating and irrigating a slope for farming, can loosen and destabilize the hillside soil.
In large metropolitan areas such as Los Angeles, San Francisco, and Seattle where homes have been built on or below hillsides, mitigation measures have helped to reduce landslide damage but have not eliminated it. Mitigation measures include check dams to reduce runoff, hillside drainage systems, retaining walls, and hillside reinforcement. Even with all these mitigation measures, almost every year after a rainy period, hillsides still slide and homes are lost.
Wherever one finds a combination of a steep slope and heavy rain, landslides and mudslides will inevitably follow. They occur hundreds of times a year all over the world. As long as people build homes on and below hillsides and mountainsides, there will be casualties and damage to property.
Gordon Gumpertz brings fiction readers another exciting action/adventure experience in his new novel RED HOT SKY. This is the author’s second book, following his highly acclaimed novel TSUNAMI.In addition to writing novels, Gordon has won gold and silver awards in national and regional short story competitions. He is a member of the Authors Guild, the Palm Springs Writers Guild, a UCLA graduate, and an instrument-rated private pilot. He keeps his website current by blogging on natural disasters and natural phenomena.
Gordon and his wife Jenny live not far from the San Andreas fault, where the Pacific Plate thrusts into the North American Plate, building increasingly high levels of faultline stress which, the seismologists say, may soon produce the Big One.
Visit his website at www.tsunaminaturaldisaster.com.
About Red Hot Sky
CO2 buildup in earth’s atmosphere reaches a tipping point. Global weather destabilizes, turns chaotic. Ice storms, dust storms, floods, blizzards, hurricanes, tornadoes pummel the earth nonstop. A secret computer model reveals that the frantic weather will peak out, and transform world climate into an alien environment devastating to human survival.
Scientists Ben Mason, Claudine Manet, and Bertrand Short are developers of the computer model. Ben and Claudine are lovers as well as lab partners. While they work frantically to head off the approaching catastrophe, a disgraced Russian general hacks into their model and sees earth’s bleak future as his opportunity for ultimate world power.
Ben, who had left the CIA to develop the computer model at the national lab, is reactivated by the Agency and sent on a perilous mission to block the rogue general’s plot. Claudine, not realizing that Ben is on a secret mission, misunderstands his absence, putting their relationship on thin ice.
Claudine is placed in charge of a massive NASA project that, if completed on time, could stop the approaching doomsday climate change. But her project is stalled by bureaucracy. Ben is on the run in hostile territory. The climate change calamity steadily approaches.
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