A natural disaster occurs as the effect of natural hazard. The UN office for co-ordination of humanitarian affairs, defines natural disaster as the “consequences of events triggered by natural hazards that overwhelm local response capacity and seriously affect the social and economic development of a region.”. According to the UN office definition, not all natural phenomenons that occur on planet earth can be termed as natural disasters. A natural phenomenon becomes natural disaster when it proves uncontrollable during its occurrence. For instance, when hurricanes strike an uninhabited island, such a phenomenon cannot be termed as a natural disaster. In this case, hurricanes have not affected in any way the lives of human beings who are far from the Island. In line with this, floods that can be managed by local authorities cannot be termed as a natural disaster. Natural disaster must have impacts on human life both socially, politically and economically.
The UN office has divided natural disasters into three categories; hydrometeorological disasters, geophysical disasters and biological disasters. Hydrometeological disasters are natural phenomena of atmospheric, hydrological and oceanographic nature that have the potential to cause loss of life, property damage and environmental degradation. Natural disasters in this category include; floods, avalanches, droughts, storms and landslides. Geophysical disasters are natural earth processes that lead to loss of life, property damage, socio-economical disruptions and environmental degradation. Some of the disasters in this category include; earthquakes, tsunamis and volcanic eruptions. While biological disasters are processes of biological origin which may involve exposure to pathogenic micro-organisms, toxins and bioactive substances. Examples of biological disaster include; insect infections and epidemics.
On the contrary, not all natural disasters are ‘natural’. Some of the natural disasters are human induced. Most of the economic activities carried out by human beings are harmful to the natural balance that exists in planet earth. For instance, floods in most of the countries are the effects of deforestation and encroachment to forest land. In addition, extreme temperatures experienced in the world are as a result of human induced activities. Green house gas emissions from industries emitted into the atmosphere thus leading to global warming. Global warming has contributed a lot to climate change.
Natural disasters have negative impacts in human life, and this has led to both developed and developing countries to address the negative impacts through the use of appropriate technologies. The negative impacts of natural disasters are social, economic and political. The social impacts of natural disaster are usually felt by poor people who live in vulnerable areas. In 1988, an earthquake registering 6.9 on Richter scale hit Armenia, killing 55,000 people and leaving 500,000 homeless. In October 1989, an earthquake registering, 7.1 on Richter scale hit Francisco, California, killing 62 and leaving 12,000 homeless. Majority of people who were affected in the mentioned countries were poor, and they tend to live in less safer environments. They live in shoddily constructed slums, vulnerable to earthquakes, avalanches, landslides and floods. The homeless people of the affected country become internally displaced persons thus influencing their lifestyles. Their social-cultural aspects may be affected due to interactions with other people. Consequently, impacts of natural disaster on the social aspect of mankind are gender issues. A large number of people who die in natural disasters are women. Women and children have less access to resources for disaster preparedness, mitigation and rehabilitation. This raises the issue of gender inequality in the society.
The economic impacts of natural disasters are both direct and indirect. The direct impacts include; damage to infrastructure, crops and homes. The indirect impacts consist of loss of revenues, unemployment and trade destabilization. For instance, in 1994 Northridge earthquake (magnitude 6.7), killed 57 people, over $20 billion of damage, and caused disruptions of infrastructure in Los Angeles area. In the same year, the earthquake hit Japan (magnitude 6.9) and 5,480 died, over $150 billion dollars of damage and a serious disruption of Japan’s economy.
Volcanic eruptions are geophysical disasters that involve forceful expulsion of molten material, gases and ash from underneath the earth’s surface. According to UN-ISDR, about 550 volcanoes have erupted in the Earth’s history. One of the volcanoes that erupted recently is Kilauea volcano, Kalapana, Hawaii. In 1983-1990, erupting lava invaded communities along the southern coast of Big Island of Hawaii, destroying more than 180 homes, highways, and treasured and archaeological sites.
Volcanic eruptions have both positive and negative impacts to human beings. The negative impacts consist of loss of life, damage of properties and disruptions of country’s economy. In addition, volcanic eruptions have toxic gas emissions which are harmful to inhabitants of planet earth. The positive effects of volcanic eruption are fertile soil and exposure of minerals.
Under UN office grouping, floods are grouped as hydrometeological disaster. Worldwide, the number of major floods disasters is growing significantly due to climate change. With climate change, the global precipitation has increased by about three percent since 1990; during this time, precipitation patterns have changed, with some places becoming wetter and others drier. From 1971 to 1995, floods affected more than 1500 million people worldwide. The United Nations estimates that half the world population will be living in areas prone to storms and other weather extremes by 2025. In the year 2001, Mozambique experienced massive floods, particularly along Limpopo and Zambezi valleys. As a result of flooding, 500,000 people were made homeless, and 700 people lost their lives. The floods destroyed crops and infrastructure, and these affected economic activities in Mozambique city.
Many countries and the world at large have invested an enormous amount of resources in prevention as well as monitoring of natural disasters. Natural disasters in the recent years have proven to have negative impacts on human survival on planet earth. As a result, many countries have invested a lot of money in projects that can predict the appearance of natural disasters. The early warnings of the occurrence of natural disasters allow residence of the concerned area to prepare in advance on how to tackle the impacts that may arise from natural disaster. Many countries are using advanced technology to track natural phenomenon and disasters. They are integrating advanced technology with internet so as to get good results concerning natural phenomenon and disasters.
Many satellites are use in monitoring Earth’s resources and natural disasters. Satellites in space have sensors that used for detections of disasters on the earth’s surface. Different satellites have a different set of sensors such as, panchromatic, multispectral, infrared and thermal . The sensors have applications in disaster mitigation, though it depends on the electromagnetic characteristics of the object on the earth surface and nature of the disaster. For instance, thermal sensors detect fire hazards such as a forest fire or volcanic eruption. Infrared sensors capture disasters related to floods. Remote sensing and Geographical information system are essential tools in detecting and mitigation of natural disasters. A number of countries and organizations are investing in the creation of websites that can convey information via the internet. The existing websites such as Natural Disasters Association site and Natural disaster-UN foundation.org are some of the sites that convey information to public on natural disasters.
In conclusion, natural disaster is one of the unpredictable phenomena that require application of advanced technology. Use of satellites and internet will be of immense importance in prevention and mitigation of natural disasters. Alerts can be conveyed to the public in time, and appropriate precautions have to be applied to address the impacts that may arise from natural disaster. Moreover, this will develop the strategies applied in disaster preparedness.
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