Every year, in some part of the world, natural hazards like earthquakes, floods, cyclones, and volcanic eruptions are read in the news. They cause many deaths and serious injuries, destroy livelihoods and damage the economies. Scientists forecast that climate change influences the frequency and severity of certain natural hazards most of which cannot be prevented but only understand their way and the place where they occur.

What are the causes?

What circumstances increase their fierceness? What effective strategies can be developed to reduce the damage they cause?

In this article we look at certain major natural hazards and the risks they pose to life, the economy and the environment.

An earthquake is the outcome of an unexpected release of energy in the Earth's crust giving rise to seismic waves. At the Earth's surface, earthquakes are obvious themselves by vibration, shaking and sometimes ground displacement with varying magnitude. Earthquakes are while caused chiefly by movement towards worse condition within the geological faults, they are also caused by other factors like volcanic activity, landslides, and mine blasts, besides nuclear tests. The subversive point of origin of the earthquake is called the focus and the point directly above which on the surface is called the epicenter. Earthquakes by their own actions rarely kill human beings or wildlife but usually the secondary factors which trigger, such as building collapse, fires, tsunamis with volcanoes being the actually causes the human disaster. Most of such problems can be possibly avoided by ensuring better construction, safety systems, timely warning and planning. The most recent significant earthquake is the 2004 Indian Ocean earthquake, the third largest recorded in history, recording a moment enormity of 9.1-9.3, the huge tsunamis triggered by which killed at least 229,000 people.

Cyclonic Storms

Tropical Cyclones
Cyclone, Tropical Cyclone, Hurricane, and Typhoon are the different names christened for the same occurrence of a cyclonic storm system occurring over the oceans. The ever most deadly hurricane was the Bhola cyclone during 1970 while the one of Atlantic hurricane was the Great Hurricane during 1780 devastating Martinique, St. Eustatius and Barbados. Another prominent hurricane was Hurricane Katrina which caused extensive damage to the Gulf Coast of the United States during 2005.

Extra tropical Cyclones
Mid-latitude or extra tropical cyclones are a cluster of cyclones defined as synoptic scale low pressure weather systems that occur in the middle of the Earth’s latitudes (outside the tropics) fully absence of tropical characteristics, and are linked with fores and horizontal gradients in temperature and dew point also called as "baroclinic zones". As with tropical cyclones, they are known by different names in different regions. The most intense extra tropical cyclones root widespread disruption and damage to society.

Volcanic Eruptions

Volcanoes are prone to create extensive devastation besides resulting in disaster of various magnitudes. The effects comprise the volcanic eruption itself which is likely to cause harm following the explosion of the volcano or the rock-fall. Second, eruption of a volcano leads to production of lava which destroys many buildings and plants, it encounters, when it leaves the volcano. Third, volcanic ash generally means the cooled ash which could form a cloud and leave thick settlement in the surrounding locations. This becomes a concrete-like material when mixed with water. The ash may cause roofs to collapse when the quantity is large while it could also harm human beings when inhaled in small quantities. Since the ash possesses the evenness of ground glass, it can create abrasion damage to moving parts like engines. Pyroclastic flows is the prime killer of human beings in the close surroundings of a volcanic eruption which comprise a shade of hot volcanic ash which gets built up in the air over the volcano and rushes down the slopes when the eruption is longer to support the rising of the gases.
Super volcano is a particular type of volcano which can kill almost three quarters of the plant lives in the northern hemisphere. The main threat from a super volcano is the enormous shade of ash which possesses a catastrophic global effect on climate and temperature for many years.

Hydrological Disasters

It is an aggressive, impulsive besides disparaging change either in the quality of earth's water or in its distribution or in the movement of water on the land underneath the surface or in the atmosphere.

Floods
A flood is a spillover of a stretch of water that sinks the land. The European Union Floods Directive defines a flood to be a temporary covering of land abnormally covered by water. In the logic of flowing water, the term may also be applied to the tide’s inflow. Flooding may emanate from the volume of water inside a body of water like a river or lake, which overflows with the result that certain water escapes its usual boundaries. While the dimension of a lake or other water body may vary with cyclic changes in rain besides melting of snow, it is not a noteworthy flood unless the water covers the land used by man such as a village, city or other inhabited area, roads, expanses of farmland, etc.

Some of the most notable floods include:

• The Johnstown Flood of 1889 where over 2200 people lost their lives when the South Fork Dam holding back Lake Conemaugh broke.
• The Huang He (Yellow River) in China floods particularly often. The Great Flood of 1931 caused between 800,000 and 4,000,000 deaths.
• The Great Flood of 1993 was one of the most costly floods in United States history.
• The North Sea flood of 1953 which killed 2251 people in the Netherlands and eastern England
• The 1998 Yangtze River Floods, in China, left 14 million people homeless.
• The 2000 Mozambique flood covered much of the country for three weeks, resulting in thousands of deaths, and leaving the country devastated for years afterward.
• The 2005 Mumbai floods which killed 1094 people.
• The 2010 Pakistan floods, damaged crops and infrastructure, claiming many lives.

Tropical cyclones can end up with widespread water logging besides storm gush.