Thursday, November 5, 2015

TYPES OF DISASTER MANAGEMENT

1.Floods

Floods refer to huge amount of water reaching land in a short span of time, causing land surface to be submerged under water – at places, where, land surface is usually not covered with water.
Floods could be caused due to natural causes, or, human activities, or, a combination of both. Floods are caused by discharge of huge volume of water in a short span of time, at a rate, such that the water can not be carried away from the scene of discharge.
Some of the possible reasons for such huge discharge of water could be:
A.     very heavy rainfall (say: due to cyclones, typhoons etc.) in a short span of time. It should be noted that the amount of rainfall itself is not a sufficient cause, the duration within which the rainfall is receive is equally important contributor
B.     breach in levy, dams etc
C.     very high tidal waves (sometimes in the aftermath of a seismic activity, e.g. earthquakes) etc. – also called tsunamis
Usually, flooding impacts a large area, wherein entire district or states might be flooded. However, sometimes, flooding is very local, i.e. limited to just one city, or, parts of it. Most often, the localized flooding is caused due to human activities, rather than natural phenomenon. A natural phenomenon might seem like the immediate trigger, but, in reality, this is caused by human activity.
There are some places, which get flooded almost every year. One such example is Bangladesh. Some of the other places which had incidents of bad flooding in the recent past include:
  • Florida, in the aftermath of hurricane Katrina (2005)
  • Myanmar (2008)
  • Portions of Coastal India get flooded almost each year
Among various kinds of disasters, flooding is unique in the sense that it has a very high degree of predictability, both in the short term, as well as long term. In most situations, flood prone areas are quite known – in the sense that they have a history of flooding. Only in very rare situations, a place might be flooded – without having any past history of flooding. Even in such cases, a careful study of the area could give an indication of possible flooding.
Flood Prone Areas
The areas, which are prone to flood-risks are:
A.     places, which have a history of flooding (most important)
B.     area receiving heavy rainfall, with not much naturally sloping landscape
C.     areas at the lower levels of naturally sloping landscape – where, the higher areas are receiving heavy rainfall
D.    areas around sea-coasts, or, river banks
E.     areas downstream of dams etc. As water level upstream of dams might rise, the dam authorities might be forced to release water (to safeguard the dam) – which might cause flooding of downstream areas
F.      areas on the other side of levies (in case, the levy gets breached)
G.    low-lying areas (say: foot of an overbridge etc.)
Loss due to Flooding
The most common kinds of loss that are caused during flooding include:
a.     Lack of water: Its an irony, that a disaster which mean water everywhere, results in lack of water to drink and sanitation. Lack of proper drinking water and sanitation causes widespread outbreak of diseases.
b.     Lack of food: Most of the food items get damaged, causing a severe shortage of food. This shortage could be for the food to be consumed in the near future, or, even standing crops could be damaged, causing long-term food shortage.
c.      Lack of utilities: Utility services might have to be turned off, for the fear of electrocution, as, there is water everywhere.
d.     Widespread damage to structure
e.     Drowning: People, livestock, goods etc. might get drowned.
f.       Snakes and other creatures: Some of the dangerous creatures which usually stay underground would be forced to come up, as their natural habitat becomes unlivable. These could prove dangerous to human beings and cattle.
g.     Submerging of vehicles and other equipments: Vehicles and other equipments might get permanently damaged – as they remain submerged under water – for prolonged duration.
Because of wide-spread impact of such floods, the suffering could be long-drawn, besides the immediate impact – as mentioned above.
Indicators of Possible Flooding
Usually, any of the following situations should indicate the possibility of flooding:
  • heavy rainfall in/around the vicinity, especially, if the specific location falls in the pathway of the water-discharge system from the area receiving heavy rainfall
  • if there is heavy rainfall/flow of water/accumulation of water, on the other side of a boundary, e.g. across a dam, across a levy, side of a river-embankment etc., because, these boundaries might get breached
As can be seen, both the above situations can be predicted to a reasonable degree. These days, the meteorological predictions are accurate enough for upto 4-5 days. Hence, its usually possible to know about the possibility of heavy rainfall about 4-5 days in advance.
Also, areas which are prone to heavy rainfall, cyclones, typhoons etc. are also well-known. Hence, the predictability is very high even in long-term, in the sense, that certain areas are known to be flood-prone. The advantage of long-term predictability is that people might be able to take long-term precautionary measures also – requiring heavy investments.
Also, for situations, where, there is a boundary between huge mass of water, and, your living place, again, keeping an eye on the following two situations should be a good indication of the possibility of flooding:
1.     increase in the volume/mass of water being built up on the other side of the boundary
2.     general maintenance and upkeep of the boundary
General level of civic maintenance is a good indication of the possibility of flooding, during rainfall. If the drains and streets are generally clean, the possibility of flooding gets reduced; on the other hand, if the drains and streets are generally choked or dirty, the chances of flooding (atleast at the local level) gets increased.
Now, that we know, how can we figure out the possibility of flooding, lets look at the possibility of preventing it.
Prevention of Flood
Sometimes, it might not be possible to prevent a flood, even if we know that its about to get flooded. However, there are certain actions that can be taken to reduce the impact significantly, or, to reduce the possibility of flooding:
1.     The first step is to keep the drainage system clean. This allows water to be carried down very fast. Choked drains cause a significant reduction in the ability and speed of the water to be drained away. In most situations of urban flooding – this is a major cause. The drains might get choked due to throwing of solid-wastes inside storm drains. These solid-wastes might include construction material, plastics, paper etc. This is a clear example, how human activity can amplify the process of flooding. Drains might also get choked due to falling tree-leaves etc.
2.     General clean-up of streets is also important. As rain-water falls down the street, it rushes into the storm drains. if the streets are not clean, the rain water trying to go into the drain – carries solid wastes into the drain with itself, which then obstructs the flow of water by the drainage system.
3.     Rain water harvesting system: As more rain-water tries to flow down the drains, it puts that much more stress on the drainage system. Instead, if there are several rain-water harvesting systems, the rainfall falling in that much area would try to go to the sub-soil of the region locally, rather than straining the drainage system. Lower is the amount of water trying to go through the drainage system, the easier it is for the drainage system to drain off the water.
4.     Desilting: The drains should be desilted before the onset of the rainy season. This prevents the drains from getting choked. And, it also inceases the holding capacity of the drain, as, accumulated silt prevents that much more water from being accumulated in the drains.
5.     Inspection and repair of dams, levees, embankments etc: Before the onset of seasons causing accumulation and/or carrying of heavy volume of water (such as rainy season), these structures should be thoroughly inspected for possible weak-spots, and, these should be repaired.
6.     Afforestation: Forestation helps in binding the loose soil. The most major impact of this is, as flood-water races through, it might take loose soil with it. This loose soil will now choke the drains, as well as water-harvesting systems, thus, rendering both of these as ineffective. On the other hand, trees will prevent soil to flow with the water, as, the roots of the trees will act as binding force. Another major impact that afforestation provides is by reducing the impact of flowing water. This has impact on large-scale flooding, such as overflowing river. As water charges forward, its speed is reduced to some extent due to resistance offered by trees. This can reduce the force of the charging water – thereby, reducing structural damage – due to weakening in the force with which water hits various structures.
7.     Local lowlands (say: foot of an overbridge) should have storm drains, so that water does not get accumulated there. These drains should have some kind of mesh covering, so that only water can flow in. Leaves and other solid debris should not go in these drains.
8.     Local embankments around low-lying houses etc: Lets say, for some reason, your house is at a level lower than its vicinity (e.g. road-level). This can happen, because, say: you have constructed a basement – which is obviously lower than the road-level, or, over a period of years, the road-level has risen due to repeated tarring etc. In such cases, you should create a “local” embankment between the street/road and your property, so that water can not flow “down” from the street/road inside your house. These embankment might be permanent – in the form of concrete structure.
Besides impacting the process of flooding itself, most (not all) of these factors also have an immense impact on the rate at which water levels might recede – after the source of the flooding has been removed. e.g. Lets say a city got flooded, after heavy rainfall. Now, once the rainfall is stopped, the water levels in the streets etc. might tend to recede. At this stage, once again, the rate at which water levels can recede is dependent on the ability of the storm drains to carry the accumulated water, as well as the total amount of water that has been accumulated – which needs to be drained out.
Being Prepared
People who stay in flood-prone areas should construct their houses using material which does not get damaged severely due to flood-water. Also, since, there is a strong risk of structural damage (for large-scale flooding), the material used to construct the house should be such that it can withstand high impact – due to the charge of flowing water. One should prefer areas, which are slightly elevated. These could be local elevations, i.e. higher parts of the city etc. There should be strong embankments along all entrances of the houses – so that flood water does not enter the house easily.
Cement bags, covered with plastic sheets might be used to keep the flood water from entering the houses.
Besides, long boots should always be kept, so that one does not run the risk of being bitten by snakes and/or other insects that might also be trying to save themselves from the twirling flood-waters.
One should keep arrangements for raising the height of items, which might get damaged in water, e.g. put a few pieces of bricks below the legs of the furniture, such as bed etc. to raise its height.
Important document should always be kept on higher shelves.
As water, food and utilities would not be available – and that too – for possibly several days, one should also take measures towards General Preparedness
Macro Level Efforts 
While some of the steps mentioned above need to be taken at municipal/city level, and, some at individual level, there are some other techniques which have been tried/used at some places. However, these require efforts at a much larger level. Some of these steps include:
  • Identified flood diversion areas: Flood waters are diverted to these unpopulated areas, so that populated urban areas may be protected.
  • Construction of dams etc. at strategic locations
  • Levees, embankments around cities lying along river/sea coasts. The flooding of New Orleans – in the aftermath of Katrina hurricane was due to a breach in such a levee.
  • Sea walls
  • Beach nourishment: The sea-beaches are widened, so that they can absorb the impact of flood-waters – due to rise in sea-levels.
  • Conversion of flood-prone areas into wetlands, where, urbanization is not allowed, i.e. one can not construct residential houses, or, any other permanent structures etc.
As can be seen, such efforts require a very high degree of financial commitment, not just for constructing the system, but, also for maintaining it.

 

2.Earthquakes

<="" a="">What Is An Earthquake
<="" a="">Earthquakes refer to shaking of earth. There is continuous activity going on below the surface of the earth. There are several large plates (size of continents) below the surface of the earth, which move (at a very slow speed). As a part of this movement, sometimes, they collide against each other. And, after the collision, they might still continue to push each other. As they continually keep pushing each other, there is a pressure building up – across these plates below the surface. And, then, at a certain time, one of the plates might slide over another. This causes an earthquake.
<="" a="">Some earthquakes might be caused by activity above the surface. For example in a mountainous region, there might be a heavy landslide. Due to a huge mass of land falling, at the point of the fall, there could be a minor shaking of earth, due the impact of fall. However, usually, such earthquakes are not very major.
<="" a="">
<="" a="">
Classifying An Earthquake
The impact of an earthquake (at any location) is characterized by two primary characteristics:

·  Intensity

This measures the magnitude of the event. Higher is the value, the bigger is the magnitude. The most common scale used for measuring an earthquake is Richter Scale. It should be understood that Richter scale is a logarithmic scale. What this means is an earthquake measuring 6.0 is 10 times more powerful than an earthquake measuring 5.0

·  Epicenter

This denotes the exact location, where the earthquake originated. The deeper it is inside the earth, the lower will be the impact on the surface – where human beings reside.
There are 100s of earthquakes taking place on a daily basis all around the world. However, most of these earthquakes are really low-intensity, too-low to be noticed. However, sometimes there are some earthquakes which are significantly intense.
Some Recent Earthquakes
Some of the earthquakes in recent times have been (not in any particular order):
1.     El Salvador; In 2001; Magnitude: 7.7
2.     S. Peru; In 2001; Magnitude 7.9
3.     Algeria; In 2003; Magnitude 6.8
4.     Indonesia: In 2004; Magnitude 9.0
5.     India; In 2001; Magnitude 8.1
6.     China - Sichuan Province; In May 2008; Magnitued 8.1; More than 68,000 dead, and, 3,50,000 injured
Fault Lines And Earthquakes
Usually, areas around fault-lines are more prone to earthquakes.
Some of the major fault lines are around:
1.     Italy (hit in 1980; magnitude: 7.2)
2.     Hayward, San Francisco in California (hit in 1906 at San Francisco; magnitude: 7.8 and again in 1989 at Loma Preita; magnitude: 6.9)
3.     Himalayan region (hit several times since 1999, at various places spanning across Afghanistan, Pakistan, India etc.)
Nature of Losses And Damages
The most common kinds of loss that are caused by an earthquake (depending on the severity) are:
Damage to structures
Causing partial or total collapse, damage to road and rail network, damage to utility carriers etc.
Sea activity
Water level in the sea could rise suddenly, causing very high waves, several meters in height, which could then flood the coastal areas. These could give rise to tsunamis, causing damage to coastal areas.
Landslide
As earth shakes, in mountainous regions, huge chunks of land could fall/slide onto lower regions of the mountains. This could have several impacts, including: changed topography, blocked roadways, damage to anything that comes in the way of the landslide, massive damage to the structure which sits on the piece of sliding land – and massing damage to the houses and roads where the piece of land finally lands. The landslide could also trigger another set of minor earthquakes.
Quake Lakes: In the earthquake in China (May 2008), landslides blocked Jiangjiang river, resulting in creations of (about 35) lakes. These lakes in turn posed severe threat of flooding downstreams - due to possible bursting. More than 1,50,000 people had to be evacuated - due to this threat of flooding.
Earthquakes typically impact a huge area, spanning whole city, and many times, several cities. The impact due to this is that besides the instantaneous damage to life and property at the time of the event, there is a long-drawn suffering.
Aftershocks
Earthquakes are also characterized by aftershocks. After any major seismic activity below the earth, the new order might take a while to finally settle down. During this time, there might be some more activity below the earth (sort of “adjusting” of the new positions for the various plates, layers etc.) These activities result in several more earthquakes. These are called, “aftershocks”. Typically, “aftershocks” are much smaller in magnitude, however, some times, one of the “aftershocks” could be more severe than the main earthquake. Also, “aftershocks” could strike up to several days after the main event.
For example the earthquake in Northern Chile (Nov. 2007) has had aftershocks till 3 days after the main earthquake.
Similarly, in China (May, 2008) an aftershock of the magnitude of 6.4 on the Ritcher scale hit 13 days after the main earthquake on May 12. This aftershock destroyed 70,000 houses and damaged many more. Each of these aftershocks were increasing the anxiety about the capacity of the quake-created lakes to hold their water.
Implications of Aftershocks
The implications of “aftershocks” are the following:
  • Structures which are not severely damaged during the main earthquake could now get damaged during one of the “aftershocks” – as they are getting continuously weakened by the earthquake and the “aftershocks”.
  • While rescue teams are trying to search through the debris of fallen buildings/bridges etc for trapped people, an aftershock could destabilize the debris further, causing these rescue teams themselves to become a victim. Besides, increasing the list of victims, it has two other major impacts:
    • Loss of trained people and specialized equipments; which in turn means significant impediment to the speed of further rescue
    • Fear among rescue teams for their own lives – due to the possibility of an “aftershock” causes them to proceed with extreme caution; thus, they are not able to work to their fullest capability
In the May 2008 earthquake of Sichuan, about 200 relief workers died in mudslides triggered by aftershocks.
  • People who have suffered during an earthquake are in psychological trauma. Each “aftershock” causes immense panic amongst them.
Recognizing an Earthquake
The most common ways to identify the onset of an earthquake would be:
  • A feeling of shaking of the ground below you, if you are sitting/standing. The most common feeling is – as if the person is feeling giddy.
  • Swinging of overhead hanging stuff, e.g. fans, chandeliers etc. However, in this situation, you should distinguish between swaying of overhead hanging stuff – due to wind
  • A feeling as if both the rear tires of your car are flat (if you are driving)
Immediate Injuries
During an earthquake, there are many ways by which one can get hurt (many times, fatally)
1.     People inside buildings could get hurt (even critically) by fall of objects/walls/ceilings
2.     People outside the buildings could get hurt by falling debris from damaged buildings, glasses etc.
3.     People traveling could get hurt by their vehicles falling off the tracks, bridges, material falling from overhead bridges etc.
4.     People could get electrocuted by snapped electrical wires
5.     People could get washed away by floods – caused due to tsunamis, breaches in dams etc.
Immediate Safety
Hence, in case of an earthquake, the safest place to be would be in an open ground – away from all kinds of buildings and tall structures.
If you can not rush out of your building, you can duck under some sturdy desk etc. which might provide protection against heavy objects falling on your body.

If even that is not possible, sit against a wall, with your back pushing the wall firmly, and, lean forward – to take your head in between both your knees, and, put your hands at the back of your head – to provide protection to your head and spine.

Or, you could stand directly below one of the door-frame in your house. This one appears a bit strange to many people. In fact, there are jokes that after an earthquake – you don’t see all those door-frames standing. So, whats the reasoning behind advising people to stand below door-frames? In most styles of construction, doorframes are made very strong, or, would have a “RCC beam” running right above these frames. Either way, this “strong” structure would take the impact of objects falling from above, and, would break the impact of the heavy objects falling on the person. If you use this posture, remember to save your arms and fingers from swaying doors etc. If not careful, they could cause damage by chopping off fingers etc. due to the banging of the doors against the frame.

Predicting An Earthquake
Earthquakes have very low predictability in short term, i.e. in most cases, there is no warning – even a few minutes before an earthquake. However, in most cases, a much higher degree of predictability exists in long term – in the sense that if a certain area is sitting on a fault line, it can be said that over a long period of time, there is a high risk of earthquake. However, whether the earthquake occurs within the next few minutes, few years, few decades – or, maybe a few centuries might not be predicted.
In April 2008, USGS reported that the state has a 46% chance of a 7.5 or larger earthquake in California state during the next 30 years. So, relatively high predictability over the next 30 years, but, absolutely zero predictability in the immediate short term!!
There are certain schools of thoughts that believe that there are certain animal instincts which provide certain degree of indication of an impending earthquake. While the beliefs in this matter are varied, the closest scientific successful attempt to predict an earthquake is known to be the incident of earthquake at Haicheng, Liaoning Province of China in Feb. 1975. An alert local community and the earthquake administration noticed a change in water level in ground-wells as well as behaviour patterns of certain animals. Taking this to be an indication of an impending earthquake, many people were evacuated out of their houses. Even though, many people had to stay outdoors in the cold, it is believed that timely evacuation helped in saving thousands of lives.
Still, the scientific community is divided about the possibility of accurately predicting earthquakes. Even if the above example is considered as an example of ability to predict earthquakes, its a matter of fact – that since 1975 many more earthquakes have jolted our earth, without anybody being forewarned. Some of these have been in China itself.
Many countries monitor the seismic activity below the earth. Since there are a lot of seismic activities below the earth on a continuous basis, these countries are not necessarily interested in these low-intensity activities. However, their interest is to see if there is a sudden increase in seismic activities. An increase in seismic activity could imply an impending earthquake in the near-future. However, how close (in “time”) might still not be predictable.
Constructing Your House
People who stay in an earthquake prone area might do well to make investments in earthquake-proofing of their houses.
The process starts with the construction of the house.
Traditionally, people in earthquake prone areas used to build homes using lighter materials, and, also materials which could be reused, e.g. wood. The advantage with wood is: being lighter – it does not cause heavy damage – when it falls on the residents, and, secondly, most of the wood can be salvaged from the debris, and, reused. This reduces the cost of rebuilding.
However, during the last several decades, due to change in construction technology, people are going in for concrete structures – specially designed to withstand earthquakes or other seismic activities. The choice of concrete over wood is gaining ground, because: if the structure is well-designed to withstand earthquakes, it would not get damaged. So, there is “no” cost of rebuilding, and, there is no damage due to falling material. However, the cost of construction would be high. Since people build houses for long-term, and, earthquakes have a certain degree of predictability in long period, there is an increasing acceptance to the idea of this investment.
Some simple thumb rules to follow for constructing a house in an area prone to earthquake:
1.     The entire construction should be a single monolithic structure, so that the whole structure can move as a whole
2.     To the extent possible, material used should be something that has been available locally. This would allow very little differential in the movement of your building vis-à-vis the material over which the house sits – thus reducing the chances of sinking
3.     Minimum use of glass in building facades. These decorative pieces could be deadly, during an earthquake. Glass being very brittle, even a minor twist in the structure could cause breakage. And, glass being very heavy and injurious could cause severe damage.

4.     Doors and windows should have fasteners, so that they can be fastened. If the doors and windows are not fastened, they might cause any of the following situations:
o    Swaying/banging of doors and windows against the frame could damage your limbs/fingers/toes etc.
o    The doors might get “stuck” due to damaged/misaligned frame – making it difficult for you to run out, or, for the rescue teams to reach you.
5.     Consult a good structural engineer to ensure that the structure is strong enough to withstand seismic activities
Earthquake-Proof Your Home
When staying in the house, simple precautions should be used:
1.     Large/heavy items should be fastened, so that they don’t fall-off, during earthquakes.
2.     Hanging items (like: fan, chandeliers, decorations etc.) should be fastened, rather than just left hanging through a hook
3.     You should be adequately prepared to live without utilities for several days. As earthquake causes severe damages over large areas, most of the utilities that we might take for granted, might not be available for several days. These are anyways generic precautions against disasters of any kind.

3.Volcanos

Volcanoes refer to eruption of hot molten lava from below the surface of the earth. As plates move away from each other, at certain places, the surface might get stretched and thinner. In such a situation, the hot molten lava and gaseous substances below this thinned surface could open up a fissure and come out.
Typically, these eruptions are always accompanied by discharge of huge amount of gaseous substances, which are various compounds of high toxicity. All eruptions (gaseous or liquid) from a volcano is at high temperature, and, the mouth of a volcano might look like, as if it’s spewing fire.
The area around Pacific Ocean is characterized by higher volcanic activity. In fact, the entire rim along the Pacific Ocean is called as the “Ring Of Fire”, because of volcanic activity along this zone.
There are a lot of volcanic activities taking place on a continuous basis, across the globe, however, not all of these are serious enough to be termed as disasters. In fact, for most of these – just a moderate level of precaution might be sufficient.
Some of the most damaging volcanic activities of the past have been:
1.     Mount Pinatubo in Phillipines (1991-96)
2.     Rabaul in Papua NewGuinea (1994)
3.     Lake Nyos in Cameroon (1986)
4.     Nevado del Ruiz in Colombia (1985)
5.     El Chichon in Mexico (1982)
Some of the deadliest volcanoes based upon the book "Volcanic Hazards: A Sourcebook on the Effects of Eruptions by Russell J. Blong (Academic Press, 1984)" are listed below. Click on the title to sort.
Place   
year   
Number of deaths   
Tambora, Indonesia
1815
92000
Krakatau, Indonesia
1843
36417
Mount Pelee, Matinique
1902
29025
Ruiz Colombia
1985
25000
Unzen Japan
1792
14300
Laki, Iceland
1783
9350
Kelut, Indonesia
1919
5110
Galunggung, Indonesia
1882
4011
Vesuvius, Italy
1631
3500
Vesuvius, Italy
79
3360
Papandayan, Indonesia
1772
2957
Lamington, Papua New Guinea
1951
2942
El Chichon, Mexico
1982
2000
Soufriere, St. Vincent
1902
1680
Oshima, Japan
1741
1475
Asama, Japan
1783
1377
Taal, Philippines
1911
1335
Volcanoes are classified as Active, Dormant and Extinct.
  • “Active” volcanoes means those which are showing activity at this time.
  • “Dormant” volcanoes those which are not showing any activity at this time, but, could show activity at any time.
  • “Extinct” volcanoes are those which were “active” at some time, but, have ceased volcanic eruptions now.
However, considering that volcanoes have a life of several million years, including “dormant” period of up to several thousands of years (sometimes), the above classification is mostly academic!!!
Usually, if you are staying/visiting in the vicinity of an “active” volcano, it would do good to be prepared for volcano related disasters.
There are several web-sites which give information on current volcanic activities. Some of the popular ones are - Global Volcano Report by Smithsonian Institute and Recent Earthquakes & Active Volcanoes list by Virtual Times.
Usually, most volcanoes do not result in any major disaster, and, people around areas of low volcanic activity have learnt to live with the volcanic activity. However, some of the volcanic eruptions which turn into disaster cause a very high number of fatalities, e.g. volcanic activity in Colombia in 1985 caused more than 23,000 deaths.
Besides, more often than not, volcanoes themselves might not cause any direct deaths, but, the post-volcanic complications cause more deaths. In such cases, the exact number of fatalities attributable to volcanoes can not be known for several years after the event.
Volcanoes themselves might not appear to be a big disaster, but, they cause several complications.
  • Because of activities below the surface of the earth, including discharge of a huge amount of material, its possible that volcanic eruptions could be accompanied by earthquakes.
  • Volcanic activity in sea could cause triggering of Tsunamis.
  • Because of discharge of very high quantity of toxic material onto the landscape, sources of water like lakes/rivers etc. could get poisoned, thereby severely disrupting the water-supply. Also, the change in water composition could impact the aquatic organisms also. Thus, overall ecosystem of the water-body is misbalanced, thus, impacting the water quality. This could even impact the areas fed downstream by these same water bodies.
  • Because of discharge of high amount of toxic gases in the atmosphere – the air could become highly difficult to breathe. Release of several gases – including oxides, sulfides, aerosols etc. changes the atmospheric mix of the area. These in turn can give rise to:
    • “acid rain”
    • Discharge of “aerosols” into the atmosphere alters the filtering impact of the atmosphere – for Sun’s radiation as well as for heat from the earth getting radiated back into the space. This can change the temperature of the area.
  • Molten lava coming out of a volcano could reach temperatures up to 1200 degrees Celsius, thus, incernating anything that comes in its way.
  • Structural damages: Lava flowing down at such a high temperature could cause structural damages
  • Landslide: As lava flows down, it gets solidified, and, modifies the landscape. However, sometimes a fresh layer of lava at high temperature could destabilize the earlier solidified layer, and, that layer could simply slide off – causing a landslide.
  • Lack of drinking water and breathable air causes people to migrate from their existing place of living to other places, thereby causing situations of migration, refugees. Besides, being emotionally distressful, there are severe kinds of physical stress and strain also associated with migration activities. And then, the resources at the destination side are also stretched beyond their normal capacity.
So, effectively, a volcanic activity could cause damage and loss of life due to one or more of the following:
  • Contact with high temperature lava
  • Earthquakes, tsunamis, landslides etc
  • Poisoning of air and water
  • Change in radiation levels and or toxic levels, impacting vegetation cover etc
  • Post-activity starvation
  • Diseases etc. due to lack of proper sanitation facilities in relief camps etc. in case large scale exodus is involved.
Even if volcanic activities do not result in too many fatalities, they still do create immense challenges in terms of humanitarian aid, due to destruction of houses, contamination of food and water. Also, one has to deal with large-scale migration, relief camps etc. which also give rise to sanitation concerns – which in turn results in various complications due to diseases related to lack of proper sanitation facilities.
During a volcanic activity, the best place to be would be indoors. Because the atmosphere is full of toxic chemicals, put filter-masks over your mouth and nose, and, use goggles to protect your eyes. Being outdoors could be one of the riskiest thing to do, as, you could be coming in contact with volcanic ashes – which could cause irritation to your eyes, skin etc. at the bare minimum, and, could also cause breathlessness, or, long term damage to you lungs, eyes etc.
Avoid weak structures, including the fresh layers which might have been formed by solidifying of lava during earlier discharges. This is usually a mistake that tourists might make. Tourists might have a tendency to get closer to the source of gaseous/lava discharge – thus, maybe, standing on such structures which are unstable and are probable to slide.
Avoid being in the path of flow of the molten lava.
Avoid fumes/vapors of petrol etc. Presence of high temperature material in the atmosphere could cause a fire, if these fumes come in contact with high temperature material, e.g. During the Nyiragongo volcanic activity (Jan. 2002), people were trying to siphon off petrol from a gas-station. A leakage came in contact with the hot lava, and, caused a blast at the gas-station, causing more than 50 people to die.
The inlets to your houses should be covered with filters, or, these inlets should be closed – to prevent toxic ashes etc. to enter your house etc. Avoid use of electronic goods, as, ashes might have entered the vent of these goods (usually provided for heat-dissipation), and, could cause short-circuit inside the devices.
Because, one of the main issues post-volcano is lack of water and food, it would help to familiarize with General Preparedeness – which also provides certain tips on being able to survive for several days – provided, preparations have been made in advance.
Post-volcano also, efforts must be made to minimize contact with the debris/ashes which have been spewed by the volcano. Clothes must be shaken and rinsed. Ashes must be vacuumed, and, the vacuum lint filter should be changed. Car filters should be changed, and so on.
If you are staying in an area, which is prone to volcanic activities, the houses should be constructed in a manner which will allow closing all vents, i.e. windows and doors should have proper caulking.
4.Tornadoes, Typhoons, Cyclones
These are winds of high-speed, many times accompanied by heavy rainfall. These cause structural damage, snapped overhead wires, and, possibility of floods.
Because of damage to structure and overhead wires, utility services could be disrupted. Heavy rainfall could cause flooding also.
Many times, these could last for a few days. In such cases, any restoration and relief activities can not even start till these few days when the activities start subsiding.
The only thing good about these kinds of natural disasters is that they can be predicted to a reasonable degree - thanks to the advancement of metrological sciences. And, in most cases, its possible to get a warning of up to several days. Usually, it is possible to take at least some preventive measures - during these few days of warning. In most cases, the preventive measure would include:
  • Moving into places which are safer, e.g. buildings which are structurally sound, and, are not prone to flooding
  • Not venturing out to sea etc for sports, fishing etc.
However, in spite of these warnings, damage to property can not be mitigated much, as, immovable structures can not be relocated.
Another important thing about these kinds of strong winds and rainfall is that they don’t appear totally at will. There are well-defined geographical areas, which tend to see incidents of typhoons and cyclones. This means that, people inhabiting these areas could take some fundamental care, while, building homes etc. These are:
  • Sturdy home, with very strong foundation and structure.
  • Typically, most people build basements. These basements provide good shelter, and, storage space for food and water to last for a few days for the entire household.
  • Proper embankments to prevent flooding etc.
  • Storage of cement-bags and plastic sheets to prepare additional embankments against flooding, if required.
The people who suffer the most are poor people, because:
  • they don’t have the means to build very strong houses, and hence, these houses get blown off/damaged
  • they don’t have the means to buy and store food and provisions for several days, causing them to take risks of venturing out during heavy winds/rainfalls to make some money
  • In coastal areas of poor country, fishermen have been known to venture out to sea, even during cyclones etc.


Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)