18 thoughts on “Blog Exercise Nine

  1. Reblogged this on All for class and commented:
    Hazards and Risk; two very different and controversial topics. A hazard is a fact, a source of potential damage to someone or something. Whereas risk is the probability that a hazard/event will occur. For example, San Francisco California sits along a fault line and has a history of earthquakes, which is the hazard. The risk is the likelihood of another earthquake occurring and at what magnitude. In terms of urban hazards, there are many. Look at the images above and you can see both natural disasters and manmade disasters. Damages from earthquakes can be absolutely catastrophic and in more than one way. When the immense energy is released along a fault line there are two significant things that can happen. The seismic waves can be so severe that entire buildings can be reduced to rubble in the matter of seconds and/or the seismic energy can cause a tsunami to form out at sea pushing it towards shore. This was seen in 2011 in Japan when a magnitude 9 earthquake shook northeastern Japan which unleashed a massive tsunami. There were several tsunami waves that struck the coastline of Japan. One wave reached run-up heights of up to 128 feet and traveled inland as far as 6 miles (livescience.com). Over 18,000 people were killed in the disaster. Governments have tried to instill mitigations that would limit the effects of earthquakes including; barrier walls to stop tsunamis and building restrictions. Some of these restrictions prohibit the construction of public buildings such as schools and hospitals near fault lines. Other building restrictions include specified materials in structures above a certain height, requiring added rebar into concrete structures. Other technologies such as Lead Rubber Bearings are used to control the vibrations from seismic activity or the Tuned Mass Damper, which are massive concrete blocks that move in order to offset the swaying of a structure.
    Another devastating hazard is fires. Rather it was started by natural means or is manmade both can cripple an urban area. The 1906 San Francisco earthquake was extremely hazardous but it was the fire that came about afterwards that leveled almost the entire city. One of the largest disasters (natural) in the U.S. during the 1800s was the Great Chicago Fire. The fire killed an estimated 300 people, destroyed 3.3 square miles and left 100,000 people homeless. Even today we can see devastating wild fires raging fires. In 2013 over 126,000 acres in Idaho were scorched and 7,700 homes evacuate during the Beaver Creek wild fire.
    One of the greatest manmade disaster has to be considered Chernobyl. Over 350,000 people had to be evacuated over the years after the number 4 nuclear reactor failed. All-in-all over 7 million people and 63,000 square miles of land were affected by the event.
    Whether it is manmade or natural these disasters have extremely long term effects on not only the urban setting but the natural environment surrounding it. For many of these hazards it is almost impossible to install mitigations that would prevent a disaster completely.

  2. Reblogged this on carlylb and commented:
    Picture one of this blog depicts the destruction of built infrastructure, most likely brought about by an earthquake. Earthquakes tend to have a wide spread impact and risk. Earthquakes involve movement of the earth and can happen on slip faults, subduction zones, dormant plate boundaries, and through continental collision. Earthquakes can be magnified by the build-up of silt and sediment which can cause liquefaction of the soil. Earthquakes happen most often at the Ring of Fire, near the Mediterranean, and in central Asia. The impact of an earthquake is determined by the depth of the earthquake, that is, how far down the location of its hypocenter is from its epicenter. The hypocenter is located underground, where the energy in the rock is released, and the epicenter is located directly above the hypocenter, on the earth’s surface, where the impact of the earthquake is the greatest. Other factors that determine the impact of an earthquake include the magnitude of the earthquake’s seismic waves, and human activity, which turns an earthquake from a hazard to a risk. The magnitude is measured by the Richter scale which ranges from zero to nine, though there is no real max magnitude. There is no known solution to prevent an earthquake from happening, but there are ways to mitigate the risk. Seismologists who monitor earthquake activity can often warn people located in areas at risk. Other mitigating measures include creating safe zones, building emergency services not located on top of faults, adjusting building codes to have earthquake proof architecture, and creating policies to turn off gas lines in the case of an earthquake. Picture three of this blog depicts a tsunami crashing over coastal land and infrastructure. Tsunami’s are caused by earthquakes or displacement on surface or subsurface. Building infrastructure along the coast increases the risk of a tsunami. Like earthquakes, tsunamis cannot be prevented, but there are ways to mitigate the risks such as: warning systems, education, and support from emergency responders are the only ways to mitigate. Picture three illustrates a massive fire consuming settlements and urban fringe on the edge of forest. Fires are caused by drought, arson, lightning, urban expansion, and land management. At the edge of a forest, picture four exhibits the increased dangers building in forest surrounded areas because they are fire prone. Picture four appears to be an example of air pollution in an urban setting. Given the setting of the photograph, it is likely that the air pollution was from anthropomorphic causes like industrial waste and fuel combustion. Where there is such an extreme amount of industrial waste there is often water pollution from leakage of barrels and pipes chemicals and improper drainage of toxic waste. The buildings appear to be degraded, as is likely corrosion that is a consequence of both water and air pollution. Picture two displays a building that has been subject to an explosion, possibly due to a nuclear reaction. Nuclear power is lethal in both the short term as well as long term if it escapes into the air, rather through accidents at testing facilities or if used as a weapon.

  3. Reblogged this on Neverending Wanderlust and commented:
    Hazards and risks are two sides of the same coin in discussing natural disasters. Hurricanes, for example, are a hazard just because they exist. The same goes for earthquakes, volcanoes, etc. However, when these disasters occur near people and have the potential to cause deaths, destruction, and damages, they become risks. The first image shows the aftermath of an earthquake. Clearly, this event caused damages to buildings, and could have caused some deaths. Cities located in high-risk areas for earthquakes (like the Ring of Fire) can attempt to mitigate the risk in a few different ways. One of the most important ways to mitigate earthquake risk is to develop a monitoring system so that people can be warned before the earthquake begins. An additional way to mitigate the risk is to develop building codes that ensure structures will not fail when an earthquake strikes. Some other ways to mitigate the risk include not building nuclear power plants or emergency services near fault lines and limiting building height.

    The second image shows the immediate aftermath of the meltdown at the Chernobyl nuclear reactor in Ukraine. Initially, the Soviet Union denied that anything had occurred at Chernobyl, and people from nearby towns were not evacuated until the following days, after symptoms of radiation sickness had already set in. Radiation quickly spread across much of Eastern Europe. The radiation contaminated the water, air, and land surrounding Chernobyl. A concrete containment structure was built around the affected reactor after the disaster in an attempt to reduce the spread of radiation. However, much of the surrounding area must remain depopulated for the foreseeable future because of the extremely high radiation levels.

    The third image shows a tsunami reaching a coastline with many structures built near the water. Tsunamis are often caused by earthquakes, but can also be caused by water displacement, like from a landslide going into a body of water. Some people believe that there is an increased risk of tsunamis today, because there is more construction among the coastlines than ever before, especially in areas that might not have the best mitigation systems. The main (and essentially only) method of mitigation for tsunamis is a warning system. Additionally, educating the public about tsunamis can help them recognize warning signs, like a quickly receding tide.

    The fourth image shows a wildfire near some homes. In desert and Mediterranean climates, fire is essential as part of a natural cycle. Fires clear dry brush often enough that there is never enough fuel to let the fire become very large. However, when people move into areas with these climates (especially in the western and southwestern United States), they want all of the fires extinguished. This allows lots of fuel to accumulate, causing large and very destructive wildfires. Lately, some areas have started using controlled burns to try to replicate the natural fire cycle, thus preventing too much fuel from accumulating. Many homeowners are still strongly against controlled burns, however. Unfortunately, in most wildfires, it is the firefighters who die.

  4. Reblogged this on Uncharted and commented:
    Hazards and Risks area all around us no matter where we go they will always be there, but there are ways that we can understand and mitigate with respect to Mother Nature. First off a hazard is based on past events and the risks are based upon probability for the future. Some of these hazards are shown in the images above. One is a tsunami, which is caused by a displacement of water. This could be from an earthquake, volcanic activity, or arbitrary mass wasting. Tsunamis are measured by two lengths, run-up and wave height. Run up is the elevation on land that the water is pushed up on. Wave height is the height at which the largest wave got up to. To mitigate tsunamis, at least in the Pacific Ocean there are buoys and if one shows displacement a signal goes off to warn people that a possible tsunami is on the way. There is technology now that can predict, if the signal is triggered, the times and places the tsunami will hit, giving people enough time to react to the situation. Another hazard is earthquakes that are shown in the images above. Earthquakes have two different scales that they are measured by, the Mercali and the Richter scales. On the Richter scale, it usually just goes up to a magnitude of 8 but can reach 9.0 if needed. The Mercali was Italian and has 12 steps of devastation that is calculated by damage done from the earthquake. Earthquakes happen along slip faults, subduction zones, continental collisions, and dormant plate boundaries. The largest one in U.S. history was in Numadrid, Missouri but little damage was done, this was along the Madrid fault line. One of the most devastating was the one in 1906 in San Francisco, California. It happened at 5:12 A.M. on April 18th, 1906 with a magnitude of 7.7 the epicenter was two miles away from the city. Not only was the earthquake devastating but it sparked a horrific fire that tore through the city. The fire was started by a gas line that had broken, when a lady turned on the stove the morning after a fire bomb exploded burning most of the city. There is no way to predict the onset of a earthquake except for looking at past events and making a probability time line unto which it will occur. The only way is to educate people on what to do when one is happening and what to do afterwards. There is also a way of implementing building codes to help with the structures withstanding that of an earthquake. Building codes are also a way to mitigate another hazard, which are hurricanes. Hurricanes are huge storm systems that develop over warm bodies of water and hit land. Normally, the most impacted lands are the ones hit by the northeastern quadrant. Hurricanes nowadays can be seen before they hit by radar, which can inform people when they need to leave for safety precautions. Volcano eruptions are another hazard to people. There is no such thing as a true dormant volcano. Multiple problems can be seen with volcano eruptions: pyroclastic flows, gases, ash, lahars, lava, and debris. Lahars are the snowmelt that runs off and floods canal systems with muddy water. Pyroclastic flows are fast flowing burning ash and gases that are extremely fast acting and there is no out running one. There have been strides in warning people of an eruption but there is still nothing to say the exact time when an eruption will occur. These are some of the hazards that poses a threat to cities all around the world.

  5. Reblogged this on crainer2014 Urban Geography and commented:
    Man’s search for hospitable living space throughout our short history has placed us in the face of natural and man made hazards and the risks that they potentially present. Our history is beset by instances of natural hazards that have wrought destruction on those unfortunate enough to be within the vicinity of the event and those that felt the overall repercussions. The event on the island of Santorini in the Aegean comes to mind as a classical event of mass destruction in which a volcanic eruption destroyed all the settlements of the island and dissected the formerly single island, indirectly bringing the collapse of the Minoan civilization on nearby Crete. Theses events of mass destruction are infrequent in the context of overall time and history, but nevertheless should serve as examples of potential hazards and the aftermaths that follow, given the higher risks that exist in our modern, over-populated world. The collection of images displayed each presents a hazard that the modern world must face and adequately access to both mitigate and protect from potential risks and plan for new areas of development.
    The top left image reveals the natural hazard of earthquakes that, depending on where you live in vicinity to a natural fault line, can have the potential for great death and destruction. The 1906 San Francisco earthquake is a prime example of an event in American history that influenced earthquake risk mitigation, which developed into a monitor and warn system of mitigating risk, but included safe zones, architecture evolution, infrastructure post-quake response, and urban planning. The image below that is a potential hazard as a result of an earthquake either on the surface or subsurface, a tsunami. Japan has historically experienced the destructive effects of tsunamis, with three major events striking the island since 1896, with the 2011 event being significant with the inclusion of a man made risk, radioactive contamination from a damaged nuclear power plant. The sheer destructive potential of a major tsunami can be seen in the 2004 Indian Ocean Tsunami, which led to the deaths of 230,000 people and the unsettling of 1.6 million. The greatest defense against the risk of a tsunami is education and warning systems to expedite evacuation of risk areas. The next image displays our historically old friend, the volcano. Given our intimate history with said friend, there are many examples of potential risks involved with living near a volcano and the risks of super volcanic eruptions such as Santorini and Krakatoa. The risks of volcanoes include the immediate heat, debris, and poisonous gases released by the volcano. In the case of the super volcanoes, the release of particulate matter into the atmosphere can adversely affect the climate, creating the potential risk of famine and other climate related devastation. The greatest defense against the risks of volcanoes is the monitoring of active sites and warning populated areas of the potential risk of an eruption. The top right image seems to display one of the man made hazards and potentials for risk, contamination due to a radioactive release from a nuclear power plant. Events such as Chernobyl, Three Mile Island, and Fukushima each present the potential for radioactive risk and highlight the need for proper management of plants and thorough analysis of plant locations and the possible hazards that are present at potential locations. Lastly, the final image displays a hazard that has been with us since we decided to settle down into clustered cities that were prime fire hazards. The best counter to potential fire destruction is the use of fire resistant building materials, adequate fire fighting resources and response time, and a well designed infrastructure. Ultimately, the presence of hazards have not prevented human beings from establishing roots in potentially dangerous areas, but these hazards have forced us to adapt to potential risks, because if anything humans are adaptive, perseverant animals.

  6. Reblogged this on maybeokay and commented:
    Hazards refer to anything with the potential to cause damage or danger. Risk, in turn, measures the likelihood of danger or incurring damage from such hazards. Volcanoes, hurricanes, and fires, for instance, are hazards; a town at the foot of a volcano, on the coast of a warm ocean, or surrounded by chaparral are risk factors. Risk, thus, involves people—where they are, what precautions they take, how they mitigate disasters—and can be impacted, if not dissipated, to some extent by decisions. Hazards cannot: they exist, whether or not they are probable in a particular place, and whether or not we decide to take the risk of getting in their way.

    Hazards are often intertwined with one another as well as risk. Earthquakes are a prime example as the sources of damage are multifold. The shaking that results from fault movement is potentially problematic itself, but can also cause water displacement that leads to tsunamis, rupture gas lines leading to fires, generate landslides, and so forth. Human actions compound the risk: building in earthquake-prone areas, installing gas lines, inadequate structural requirements, etc. Other natural hazards follow a similar pattern: while lava from volcanoes can be damaging, so too can pyroclastic flows, ash clouds, landslides, flank collapses, environmental repercussions, fires, etc.—the effects of all of which are made worse by inadequate awareness, planning, and precautions by people in the vicinity (also often by the strict fact that there are people in the area).

    Indeed, of factors influencing risk, location is an obvious and important one. This of course refers to building in or near areas with a history of hazards—near active faults, for example—but also to the physical geography of the area, whether the features have the potential to exacerbate hazard damage (marina district liquefaction in San Francisco, below-sea-level location of New Orleans), whether the geography encourages hazards (tornado touchdowns being more common in plains areas than rougher terrain, for instance) or makes evacuation more problematic (islands, areas with limited connections).

    Infrastructure is also important in risk promotion or mitigation. In some cases it can help reduce the risk of disasters or increase resistance: incorporating more green space to cope with storms and potential flooding, building codes that help buildings withstand shaking during earthquakes. In other cases, infrastructure involves the strategic locating of disaster management services, facilities, warning systems, and utilities so that an area can better cope with disasters both in advance (warning systems, evacuations) and after the fact (recovery, injuries, reduced risk of fires or loss of utilities).

    Organized and widespread education efforts are also important: a well-built building is good and well, but enough shaking during an earthquake will eventually fell it. Teaching people to get out of it and into an open space or stand under doorframes, however, can significantly reduce fatalities.

    These examples all refer to natural hazards, yet the importance of location, infrastructure, and education also applies to anthropogenic hazards—air and water pollution, hazardous waste, etc. In both cases, however, the role of people in compounding or mitigating risk is inseparable from the ultimate outcome of hazardous events. Indeed, the word “hazard” doesn’t apply unless there is someone or something to be affected (i.e. a wildfire is just a natural event until it’s close to a backyard).

  7. Reblogged this on urban geographical issues and commented:
    A hazard is define as the potential to cause a dangerous event that can impact humans, society and the enviroment. There are natural and manmade hazards. The manmade hazards are those that cause human irresponsible approaches and handling of sociesties’ functions. The natural hazards are those that are most of the time unpredictable and are of natural origin.
    Society has change in the past few hundred years since the Age of Discovery and the Industrial revolution. In the beginning we saw society as part of nature and the perils and the security that came with it, as part of our very own existence. Today society has move beyond that world view and has often regard itself as separate from the natural world. But when a natural calamity occurs such as natural disasters or the media’s emphasizes on climate change, we are reminded that we are part of this biosphere we called “Earth.” From the start of human conscious there has been a fear of the great unknown, specially of those related to disasters. In fact, early humanity developed modes and cultural practices to deal with catastrophic events that saw a relationship of all the ills to the unforeseen spiritual world. From early animistic religions to modern world faiths, human populations saw natural hazards as the “wrath of the gods or God” and these types of hazards played significant roles in the building of their dogma. Nowadays with the advancements in science we have come to understand the causes for the many of the natural and anthropogenic hazards, but it wasn’t that easy to make this transition to scientific inquiry in the field. Catastrophist ideals rule the field of early geology school of thoughts which states that all earth disasters had to be cataclysmic to allow for the stratigraphy geological record to fit the Biblical genealogy of creation at 4004 B.C. The Lisbon Earthquake of 1755 at 9.0 on the Richter scale brought in the debate that not all, if any, of the natural hazards are the “act of God.” John Mitchel, geology professor at the University of Cambridge, sought a scientific explanation for the Lisbon Earthquake countering the belief from John Wesley that the event was God’s punishment for the wickedness in the city. Further, later Charles Lyel introduced the gradualism approach that all processes on the earth’s surface are a result of past events that can also be observed today, given rise to uniformitarianism. Uniformitarianism states that geological processes follow natural laws based on physics and mathematics that are applicable by scientific observation. As result, of all this we have better started to understand natural and manmade hazards (Bryan. 2005).

    The science approach to look at hazards divides the field on how humans effect the natural environment and the other on how nature effects itself and undergoes changes. The anthropogenic side is concern in which the world human populations impact the climate and the earth by landuse methods. The other side that looks at the hostility on the natural world and its divided among the lines of chronic and episodic events that effect the planet and people. Chronic natural hazards are those like desertification, soil degradation and melting of the polar ice caps. Episodic or periodic natural hazards are those that are large in magnitude and occur during a short period of time such as earthquakes and volcanoes.

    Bryan, Edward. Natural Hazards. 2nd. Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo: Cambridge University Press, 2005.

  8. The top left image is that of the dame an earthquake can make. Earthquakes occur as a result of the sliding of tectonic plates past one another. The earth is made up of different tectonic plates. These plates are constantly moving and as they move along, above or below one another the pressure builds up and eventually they abruptly move causing an earthquake. Earthquakes cause lots of damage in high density places. The causes of deaths have gone down rapidly as building technology better adapts itself to earthquakes. The original cause for most deaths in major cities when an earthquake occurs is not the collapsing of buildings, which did also happen, but the fires that were caused by the earthquakes. Gas pipe lines that are used to fuel the city would rupture and ignite and start an uncontrollable fire the would inevitably flatten the city until proper codes and fire responders were more available. Most major United States cities have had at least one catastrophic fire. Earthquakes can not only cause fires but they can also cause floods. Earthquakes can cause the breaking of dams and catastrophic flooding downstream. One of the most interesting examples for me is the Three Gorges Dam. Reservoir induced seismicity is one possible problem with the dam. This occurs when the pressure of the water build up pushes on the fault line and possibly causes earthquakes. The dam itself is located right on top of a major fault line in China. Such a massive dam requires a very large foundation and the foundation was built right on the fault line. The Dam is believed by some to be cause for the massive increase in seismic activity since its construction. Not only is the river most likely the cause of more and more earthquakes but when the two plates shift the result could be catastrophic. The dam has already cause many to lose their homes downstream due to rising waters and now those people are concentrated in much larger cities because of the loss of their homes. If the damn breaks the large mass of water that will be released may cause a disastrous flood in cities like Chongqing, who’s population is over 30 million people. Earthquakes also cause tsunamis. When tsunamis hit coast lines they wipe out entire cities. The force of the wave, or series of waves, is so strong that it carries away anything in its path. An interesting result of the earthquake in Japan was that it was not the earthquakes itself that took out the nuclear power plant but the tsunami that was caused by the earthquake. The nuclear power plant itself was built to be resistant to earthquakes but when the water invaded the nuclear plant, the results were catastrophic. The tsunami released radioactive material in the areas surrounding and then back into the ocean causing massive damages to the ocean and the earth itself. As we see in this example the natural disaster doesn’t stop at the first disaster, but causes a series of disasters to follow as a result of the first.

  9. When it comes to the subject of naturally occurring disasters and their affect on urban centers and other high density areas, it is important to note one very simple factor that puts a city infrastructure at high risk in situations such as tsunamis or tornado’s or earthquakes. There is an extreme amount of variability that occurs within a city system. This creates an infinite number of scenarios that cannot all be accounted for in emergency planning. Beyond the major preparations, like don’t build on the coast if you’re worried about hurricanes and don’t build on fault lines if you have a lot of expensive china. The only real way to deal with natural hazards is to create the best network of preparedness and response. Before Katrina, we know now that a majority of the urban New Orleans populations was lower class and highly susceptible to climate hazards due to their inability to take refuge outside the city or their lack of access to proper information and emergency evacuation attempts. Proper preparedness would have told the U.S government and relief groups all they needed to know. The topography and condition of the levee’s created a lose-lose situation. The levee’s that actually did end up failing were located in the poorest neighborhoods of New Orleans and it has been speculated that they were not up to code for several months before the storm. But sadly as we all recall, it was not the lack of preparedness that arguably made Katrina one of the worst natural disasters of the past decade, it was the complete lack of organized response that accompanied the storm. Nearest estimates concluded it took FEMA over two days to get water to the people stuck in the Super Dome. The disintegrating situation in New Orleans was compounded by the poor waste/hydrological engineering of the city (And the fact that they decided to build it several feet below sea level in alligator infested swamps). Almost every block of New Orleans had several feet of standing water.

    What does all of this teach us? It teaches us that natural disasters can occur suddenly, with little warning, like a tornado or earthquake. In which case it is just like real estate; what is important is location, location, location. A fault slips somewhere remote and nowhere near a major city, and suddenly that earthquake is no more than a tree that fell in the forest with no one to hear. Did it even make a sound? But you put that same variable near Haiti, and you have massive reprocussions. A developing nation with very rapid and unregulated population growth will have very little in terms of building codes. The damage from a 7.0 magnitude earthquake would be damaging in even the most modern of cities, but you put that near a city like Port-au-Prince, combined with a large population of marginalized lower class living in shanties and a lack of responsive services, and you have a real humanitarian issue. In the case of other natural disasters however such as hurricanes and one could even say volcanic eruptions, these incidents occur within a wider frame. Meteorologists can track a potential tropical storm from birth till it makes land fall (But they can’t tell me for sure whether I’ll need a rain jacket or not. Useless). And volcanoes are very seldom single catastrophic outbursts of biblical fury. There is usually sufficient evidence of geological activity before an eruption (A quick RIP to the two teens boiled alive in that natural spring in the film “Dante’s Peak”). These natural disasters carry a sense of “Well, told you so…” with them. With the expectation that for all intents and purposes, a sane human being will flee for their life from a mountain spewing smoke or a hurricane that’s liable to leave someone’s boat on the freeway. 

  10. Reblogged this on esobrien and commented:
    Around the world, today and throughout all of history, hazards have always existed. Their risks, however, vary from situation to situation as a result of urbanism. The major hazards we experience are earthquakes, tsunamis, and volcanoes, and their resulting effects on cities as seen in the pictures.
    Earthquakes, byproducts of tectonic plate movement, can take a number of different forms, each of which involves a different risk level on society, as seen in the first picture. Earthquakes that form from slip-faults, such as all along California, are a result of plate boundaries sliding together. However, there are also earthquakes that emerge from continental collision, such as in the India and China border. The level of risk changes over time, based on the depth, magnitude, and level of human activity. Because they’re caused by moving plate boundaries, there is no way to prevent the hazard of earthquakes themselves, but it is possible to mitigate the risk. A major way to lower the risk of earthquake destruction is building codes, whether that is through urban planning of the city to avoid building on top of faults, or not putting specific buildings on the boundaries. A good example of a lack of mitigation tactics is the destruction that occurred as a result of the Chernobyl accident, pictured in the second photograph. The placement of this factory led it to be one of the largest manmade disasters because of its billions of dollars in damages and impacting thousands in the surrounding areas.
    Another very destructive hazard is a tsunami. They form largely as a result of displacement of water from an earthquake occurring out at sea, either surface or subsurface. These can have a significantly increased risk on society compared to other hazards if there are not sufficient warning systems and education of people who live in at-risk areas. As it was with the 2011 tsunami in Taro, Japan, there were over 19,000 deaths and around one million buildings destroyed or very badly damaged, and over $235 in overall damages.
    Additionally, fires are a large risk that ties in with urban planning. As depicted in the bottom picture, fires can play a large role in the destruction of entire cities. As in the San Francisco earthquake of 1906, the majority of the devastation was caused by the fires that spread post-earthquake. Fires are a large problem today as well because of fire suppression methods of forest management. In these situations, controlled burns are not implemented, typically in areas along urban fringes, so when a natural fire does hit it consumes all the built up dry undergrowth, causing it to catch faster, last longer, and burn brighter.
    A final hazard that can have a major impact on nearby cities is a volcano. Formed by divergent or convergent plate boundaries they can have varying impacts just like the other hazards. Those formed around the “Ring of Fire” in subduction zones have a very large impact, with their pyroclastic flows, gas, ash, and magma.
    Natural hazards can be monitored and warned about, but in a culture we live in today in which humans have a mindset that they cannot be stopped by anything, including nature sometimes, these strategies for protection lose their significance and people continue to lose their lives and lifestyles.

  11. Reblogged this on meshari86 and commented:
    Natural disasters are a test or significant damage caused by a natural event on the seriousness of the enclosed and there are multiple definitions of the disaster, identified by international organizations and bodies, national specialized such as Earthquakes, Volcanoes, Floods, Tsunamis, and Tornados.
    And, the most of scholars read and analysis disasters by the old events that called Hazards. Hazards is defined that it is the past natural disaster occurred in an area and damaged it. The scholars also can predict and expect the disasters by their concepts and experiences. They called it the risk, which it will happen it the future.

    In fact, Earthquakes may occur in ruins and a large degree determine the earthquake and measure it from 1 to 10. The maximum score is between the 7 to 10 earthquake that can destroy the entire city and dug underground until they disappear with the damage to the many cities. Another natural disaster, Floods, which occur as a result of the accumulation of large amounts of rain for a long period of time in a specific area. Some water disaster that comes in the long term, including coastal erosion, which leads to the sinking of some cities. Moreover, Tsunami is a huge wave peripheral contains a series of waves and a tremendous amount of water caused by earthquakes, volcanoes. Then arise when the tidal wave vertical sliding occurs at the bottom of the sea would undermine the lateral surface of the seafloor arise on the surface of the sea. The one of the famous tsunamis resulting from the earthquake in the Indian Ocean in 2004, which hit the coasts of many countries, including Indonesia, Sri Lanka, Thailand, India, Somalia and other terms and described the quake as one of the worst natural disasters that hit the Earth at all killed more than 20000 people.

    Many of the reports of the phenomenon of growing natural disasters of all kinds in the period between 1990 to 2007, and especially floods, hurricanes, landslides, desertification and drought, but it’s not, thanks to nature alone, but as a result of the occupation of the global ecosystem, due to the futility of human nature, such as deforestation and emissions of fossil, and their response seas and drying Lakes, and excess consumption of rivers, lakes and groundwater depletion, and so intertwined nature of disasters and catastrophes in the human condition.
    Also, the poor countries and underdeveloped adversely affected more than the developed countries, in the face of natural disasters, it has conducted the report a comparison between Japan and sophisticated Philippines underdeveloped and ,which are subjected to disasters similar as the seasonal monsoon, earthquakes, volcanoes with respect to the loss of life, and the vast difference. He also presented the economic losses arising from the disaster and its impact on the rate of increase of income in a number of countries, developed and developing world, and found it very marginal in countries such as the United States and high in Madagascar.

    In a comparison report varying impacts of disasters on different segments of the population in one country, such as South India, and the state of Cali in Colombia, Costa Rica. It found that the marginal areas inhabited by the poor in the suburbs of major cities and rural areas inhabited by the poor peasants more affected in the life, property and infrastructure of basic urban neighborhoods. As so far the effects of disability in the development and worsening poverty, loss of savings, jobs, education and others. This concept as the marginal neighborhoods and shantytowns fragile structure, and lack of planning, infrastructure, and resources to deal with disasters


  12. Reblogged this on parymayne and commented:
    A risk is different from a hazard in the sense that a risk can be mitigated. A risk occurs when there is serious potential for death, destruction, and damage. A volcano is a hazard for the simple fact that it can erupt, but unless it is a large enough volcano to disturb the atmosphere and create climate change, it only becomes a risk when people live near enough to feel the effects of the eruption’s gas ash and magma. Fire is always a hazard, but it becomes a bigger risk when development patterns and building codes are not regulated to prevent its spread. Codes have gotten stricter since the tragedy pictured in the bottom right corner so that firers are more likely, to be contained and not wipe out entire city blocks. An example of a hazard that did not come with a risk is the new Madrid Earthquakes that occurred in 1811 and 1812, due to the low levels of development there was not a lot of costly damage associated with the 7 to 7.7 magnitude earthquakes. If that quake happened today, St. Louis alone would probably see billions of dollars in damage making the earthquake a huge hazard.
    Humans have greatly increased risks by developing heavily in coastal regions, building nuclear power plants, and developing in heavily forested areas. The coast is where Tsunamis and Hurricanes strike. Tsunamis are hard to predict because they do not become noticeable until just before they reach shore. Being unpredictable this risk is very hard to mitigate, and coastal areas in the Ring of Fire fall victim to them frequently. Risks associated with hurricanes can be mitigated it a good evacuation plan and building codes are in place and are followed. The problem is that they are oftentimes not followed.
    As we saw in Fukushima, nuclear power risks are often associated with earthquakes, which can be very unpredictable, and very frequent in some parts of the globe. The biggest danger associated with nuclear power is that the effects spread as the radiation pollutes the water and soil spreading far past the sight of the initial catastrophe. Other risks associated with nuclear power are linked to human error. One mistake could be devastating and deadly.
    Forest fires are also turning into high risk scenarios as human settle closer and closer to forest and push for new policies that increase the risk associated with a forest fire when they happen. Now human’s demand for water has made the forest dryer and more susceptible to burning. Forest management practices have changed to require fires to be put out even though fires are needed to produce the next generation of plants and control the amount of underbrush. People also bring with them building material and landscaping that catch fire easily. Because of all of these factors wild fires have become more frequent and more difficult to control. We humans have developed in the way of nature and turned the hazard into a risk.
    Modern technology has brought us tornado shelters, storm shutters, levees, and building codes and regulations. If we used these innovations and maintained them risk would be smaller and lives would be spared. Human’s cannot control hazards, so rather than ignore the inevitable, let’s learn to take the proper precautions to prevent death, destruction, and damage.

  13. Reblogged this on jennnyp123 and commented:
    Natural disasters such as hurricanes, earthquakes, and tsunami’s can all be characterized as a hazard to human health and environment, yet the risk associated with such events is directly tied to human activity. When these natural events occur near people they have a high risk of causing death and destruction in the face of poor planning and mitigation practices. Catastrophic events such as the ones pictured above often bring about multiple different hazards to human health which must be addressed in different ways. Earthquakes, for example, have the potential to cause a great deal of destruction from movement alone but can also lead to subsequent hazards. They occur commonly in specific places such as on fault lines and for various reasons with differing magnitudes. Pictured above is the potential immediate damage felt by buildings in the aftermath of an earthquake. However, earthquakes can also lead to other hazards such as tsunamis, landslides, flooding due to damaged infrastructure, and widespread fire as gas lines break and ignite. People that live in regions with high risk of earthquakes can mitigate these hazards through methods such as monitoring systems and updating building codes. We now have the technology to predict where these events are likely to occur in addition to materials necessary to build infrastructure to better withstand such an event. The risk of fires as a result of earthquakes, such as the one pictured above which occurred in San Francisco in 1906, has been reduced due to more effective planning strategies and technology such as the ability to shut off these gas lines in the aftermath of such an event. Today we are more educated about how to deal with these natural disasters as well as the best way to stay safe if one occurs. Growing up in california on the San Andreas Fault we had earthquake drills even more frequently than fire drills in elementary school where we were taught the safest place to be within a building as well as how to protect your neck and head.
    Tsunamis like the one pictured above have also proved very hazardous to human health. Often caused by earthquakes or other natural occurrences causing water displacement these massive waves pose serious risk for those living in costal areas. Billions of people, 44 percent of the worlds population, live in coastal regions with more construction today than ever before. The devastating effects of tsunamis kill thousands of people as the only sure way to survive such an event is evacuation which is often difficult especially when they strike unexpectedly. Today we have methods to predict when and where such an event will occur although it is usually with very little warning. Mitigation efforts also include informing people in these regions of warning signs such as rapidly receding tides yet the only sure protection is avoiding construction in regions prone to these type of disasters.
    Wildfires such as the one pictured above are a common natural occurrence but become a hazard for humans who increase their risk for destruction in various ways. Fire is an important part of the natural cycle of things in certain climates. In desert and Mediterranean climates wildfires occur frequently burning the ground vegetation before it builds up. With limited fuel these fires never become too large but when people move into these regions and build homes, such as in the western United states, they extinguish these fires quickly and this fuel accumulates. As a result, when these fires do occur they are very far reaching and destructive. In areas prone to wildfires some have started doing controlled burns to limit the effects of unplanned ones yet many oppose this practice near residential areas which ironically are the most at risk.
    Anthropogenic hazards also pose a serious risk to human environments. These man made disasters such as the destruction of the Chernobyl nuclear power plant pictured above are often the product of human negligence or error. In the case of chernobyl an explosion and subsequent fire released massive amounts of radioactive material into the environment causing devastating effects. The city was abandoned and the latent effects on the environment and human health, such as caner and deformities, are still being accounted for. For hazards of this nature mitigation practices include thorough analysis and planning of plant locations as well as proper management at the site. Since as humans we have very little to no control over the natural events that occur on earth we must do our best to base our actions around the forces of nature. Through effective planning, studies and observation we must work with our environment and make choices that minimize risk without trying to interfere with the earths natural cycles. Especially in the face of climate change it is now more important than ever that we stay in tune with the natural environment and acknowledge its power beyond or control as well as monitor the vast influence our activity has on the planet and the ways in which we are able to interact with it.

  14. Reblogged this on The Urban World and commented:
    Our planet holds many hazards for the various organisms inhabiting it, and any structures they may build. In particular, our own cities, sprawling, are often situated perfectly to bear the full brunt of nature’s actions, such as an earthquake, or volcanic eruption. In urban planning, understanding these potential hazards and planning so as to minimize the amount of risk created by these pervasive threats is of utmost importance in preventing massive loss of life and mind-boggling amounts of property damage. Unfortunately, while much can be done to mitigate the effects of many hazards, others are inherently more risky as hazards. So, while a building may be built proof against a statistical standard of earthquake magnitude, a tsunami may easily destroy the building. Unfortunately, often the only effective method to mitigate the risk against human life is to evacuate quickly. More unfortunate the many times that evacuations are impossible due to the sudden, overwhelming nature of the hazard, as is the case with many tsunamis, as well as volcanic gas and ash emissions, capable of decimating populations with little warning. Unacceptable are the times when warning is available and evacuation is ignored. Given that civic authority who would ignore evacuations likely are also inadequate in many other areas of crisis management, possibly infrastructure maintenance, and the ineptitude displayed against several of the largest disasters of the last decade can only be dejectedly accepted. The hazards created by ourselves are the most troubling, for those are risks created by ourselves, creating unimaginable tragedy in their wake, as has been the case with nuclear reactor meltdowns. These meltdowns can cause immediate destruction from fire and radiation sickness, and an increase in cancer rates for those nearest the disaster. Combined with the waste nuclear energy production creates, and nuclear energy as a gateway to an idyllic, energy rich utopia as conceptualized in the ’50’s is quickly seen as so much wishful propaganda representing the unrealized goals of failed social architects. So it would seem prudent to consider excluding nuclear power from future infrastructure development to remove the potential risk of hazardous nuclear power plant events. Unfortunately, while a citizen can be protected as much as possible from natural hazard, forewarned to evacuate whenever the civic authority is able, and kept safe from imperfect energy sources, there are limits as to what can be done to protect a citizen from their own foolishness. In particular, as sprawl as diffused on the latest edge, private residences push further and further into wilderness. In many areas, this area is uncleared, leading to the potential for natural wildfires to destroy their properties. Sick with worry at this prospect, the average homeowner will relentlessly stand vigilant against any and all fire in the area, demanding absolute protection even the smallest fires, the most remote chance of disaster, and being even more vehement in their opposition to controlled burns to regulate the growth of underbrush. As said underbrush continues to intensify, it results in seasons where any extended dry spells produces an area that is ready to go up at the drop of a match, causing larger, hotter, faster fires that destroy the forest rather than simply underbrush.

  15. There are multitudes of natural and human-caused disasters that pose as hazards or risks in urban areas (a hazard is an event that has happened in the past, and a risk is a possibility that something will happen). Many of these dangers have geologic roots, while others stem from the ocean, atmosphere, or other sources. Plate tectonics create plenty of these hazards and risks. The geological phenomenon that causes the movement of Earth’s continents is what also creates volcanoes and causes earthquakes. Volcanoes are created primarily through divergent and convergent plate boundaries. Divergent boundaries, created by the spreading out of major plates, have very limited urban impact. They create less powerful volcanoes that produce basaltic magma and have low viscosity (meaning the flowing of molten rock is not inhibited much). With low viscosity, volcanic eruptions are more silent and less explosive. Despite the formation of Iceland by divergent boundaries, urban activity is very minimal along these plate boundaries, greatly lowering the risk. Convergent plate boundaries, however, pose a bigger danger to urban areas. These boundaries are formed by subduction zones, where one tectonic plate slides under another due to a difference in density. In one form of subduction, basaltic oceanic crust (being more dense) plunges under the less dense, silica-rich continental crust. This creates volcanoes with magma that is rich in silica. The silica raises the molten rock’s viscosity (that is, it is harder for the magma to flow). This results in explosive eruptions, emitting abundances of superheated gas, ash, and lava. The gas, being heavier that air, flows quickly downslope. This pyroclastic flow, coupled with a much larger urban presence along subduction zones, poses a real threat to cities. Pyroclastic flows are one of the most expensive hazards, burying homes and cars with ash and taking human lives through suffocation, burning, or debris collision.
    Another major geologic hazard is earthquakes, which can occur along subduction zones and slip faults. Earthquakes can strike all around the Ring of Fire (a chain of subduction zones encircling the Pacific Ocean), the Mediterranean, Central Asia, and any other place where there is a fault. Earthquakes are among the most destructive hazards, causing potentially thousands of deaths and billions of dollars in damage. The best way to mitigate damage caused by an earthquake is through architecture—designing or retrofitting buildings and bridges to better withstand severe tremors.
    Another natural disaster, tsunamis, can form as the result of an earthquake. When an earthquake occurs below the ocean floor, the tremors displace a sizeable amount of water, creating an enormous surge of waves sometimes reaching as high as 100 feet (nationalgeographic.com). 80 percent of tsunamis occur with the Ring of Fire (nationalgeographic.com). The best form of defense is early warning that permits people to find higher ground (nationalgeographic.com).
    Hurricanes and other tropical storms are another major hazard for coastal settlements. These storm systems bring heavy rains, very strong winds, and sweeping floodwaters. Much of the damage caused by hurricanes is from storm surge, a rise of water level generated by the storm system (nws.noaa.gov). This surge of water sweeps over the coast, often causing damage to coastal urban areas. What makes storm surge even more dangerous is when it is coupled with high tide, further raising the water level and inflicting more damage. Storm surge has proven to be deadly to settlements below sea level, perhaps where potential damage is greatest.
    One last common risk in urban settlements is fire. Fire often carries potential for damage when suburban areas stretch or sprawl too close to burning areas (forests, etc.), especially when building materials that are fire-prone are used generously. Fire can also be costly through arson, “the illegal burning of a building or other property” (Merriam-webster.com).

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