introduction to disasters
Disaster is an undesirable occurrence resulting from forces that are largely outside human control, strikes quickly with little or no warning, which threatens or causes serious disruption of life and property including death and injury to a large population, and requires therefore, mobilisation of efforts over that which are normally provided by statutory emergency services.
CLASSIFICATION OF NATURAL DISASTERS
Identification and classification of disasters are being considered as a scientific step to deal promptly and efficiently with disasters. Broadly, natural disasters are often classified under four categories.
DISASTER MANAGEMENT
The International Federation of Red Cross & Red Crescent Societies defines disaster management as the organization and management of resources and responsibilities for dealing with all the humanitarian aspects of emergencies, especially preparedness, response, and recovery so as to reduce the impact of disasters
Three stages of disaster mitigation and management are:
- Pre-disaster management involves generating data and details about the disasters, preparing vulnerability zoning maps, and spreading awareness among the people about these disasters.
- During disasters, rescue and relief operations like evacuation, construction of shelters and relief camps, supplying of water, food, clothing, and medical aids, etc. should be provided on an emergency basis.
- Post-disaster operations involve the rehabilitation and recovery of victims. It should also consider capacity building so as to cope up with future disasters.
Floods
Inundation of land and human settlements by the increase of water within the channels and its spill-over presents the condition of flooding. Floods are relatively slow in occurrences and mostly, occur in well-identified regions and within the expected time of year. Floods occur commonly when water exceeds the carrying capacity of the river channels and streams and flows into the neighboring low-lying flood plains in the form of surface run-off.
Floods are also caused due to a storm surge (in the coastal areas), high-intensity rainfall for a considerably longer period, melting of ice and snow, reduction in the infiltration rate, and presence of eroded material within the water due to a higher rate of erosion.
Consequence and Control of Floods
Frequent inundation of agricultural land and human settlement has serious consequences on the national economic system and society. Floods don’t only destroy valuable crops each year but also damage physical infrastructures like roads, rails, bridges, and human settlements. Millions of people are rendered homeless and also are washed down together with their cattle. Spread of diseases like cholera, gastroenteritis, hepatitis, and other water-borne diseases spread within the flood-affected areas.
Methods to control floods:
- Construction of flood protection embankments within the flood-prone areas, construction of dams, afforestation, and discouraging major construction activities on the upper reaches of most of the flood-creating rivers
- Depopulating the flood plains or Removal of human encroachment from the river channels.
- During heavy rains, trees help in reducing the risk of flooding. Experts say that trees act as a barrier against floodwater and also prevent soil erosion. They help in reducing the sediment going into rivers and increasing water absorption into the ground. This helps in slowing the flow of rainwater into swollen streams and lower peak flood levels.
Earthquakes
An earthquake is a sudden slip on a fault resulting in ground shaking. It also radiates seismic energy. Earthquakes are by far the most unpredictable and highly destructive of all the natural disasters that may be caused by volcanic or magmatic activity or other sudden stress changes in the earth.
Earthquakes that are of tectonic origin have proved to be the foremost devastating with a large area of influence and the once due to eruption, rockfall, landslides, subsidence, particularly within the mining areas, impounding of dams and reservoirs, etc. have a limited area of influence and therefore the low scale of damage.
Socio-Environmental Consequences of Earthquakes
It becomes a calamity due to its dimensions, magnitude, and suddenness when it strikes the areas of a high density of population. It not only damages and destroys the infrastructure, transport, settlements, and communication network, industries, and other developmental activities. It renders a large part of the population in affected areas, which puts extra pressure and stress, particularly on the weak economy of the developing countries that is why it is usually related to fear and horror.
Effects of Earthquakes
- Ground shaking
- Faulting and Ground Rupture
- Landslides and ground subsidence
- Tsunamis
Earthquake Hazard Mitigation
It is impossible to stop the occurrence of an earthquake; hence, the only best option is to emphasize on disaster preparedness and mitigation instead of curative measures such as:
- Establishing Earthquake Monitoring Centres (Seismological Centres) for monitoring and fast dissemination of information and data among the people in the vulnerable zones.
- The use of a Geographical Positioning System (GPS)can be of great help in monitoring the movement of tectonic plates.
- Preparing a vulnerability map and dissemination of vulnerability risk information among the people and educating them about the ways and means minimizing the adverse impacts of disasters.
- Modifying the house types and building designs in the vulnerable areas and discouraging construction of high-rise buildings, large industrial establishments, and large urban centers in such areas.
- Making it mandatory to adopt earthquake-Resistant Designs and use light materials within major construction activities in vulnerable areas.
An earthquake is a sudden slip on a fault resulting in ground shaking. It also radiates seismic energy. Earthquakes are by far the most unpredictable and highly destructive of all the natural disasters that may be caused by volcanic or magmatic activity or other sudden stress changes in the earth.
Earthquakes that are of tectonic origin have proved to be the foremost devastating with a large area of influence and the once due to eruption, rockfall, landslides, subsidence, particularly within the mining areas, impounding of dams and reservoirs, etc. have a limited area of influence and therefore the low scale of damage.