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| Disaster Relief |
Disaster
Data & Statistics Centre
for Research on the Epidemiology of Disasters (CRED) launched
the Emergency Events Database (EM-DAT). EM-DAT was created
with the initial support of the World Health Organisation
(WHO) and the Belgian Government. Deaths
from disasters Other
human impacts from disasters 10
of the Deadliest Natural Disasters in 2018 Top
11 Deadliest Natural Disasters in History Drought Many
plant species, such as those in the family Cactaceae (or
cacti), have drought tolerance adaptations like reduced
leaf area and waxy cuticles to enhance their ability to
tolerate drought. Some others survive dry periods as buried
seeds. Semi-permanent drought produces arid biomes such
as deserts and grasslands. Prolonged droughts have caused
mass migrations and humanitarian crises. Most arid ecosystems
have inherently low productivity. The most prolonged drought
ever in the world in recorded history occurred in the
Atacama Desert in Chile (400 Years). Earthquake Earthquakes are measured using measurements from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe. The more numerous earthquakes smaller than magnitude 5 reported by national seismological observatories are measured mostly on the local magnitude scale, also referred to as the Richter magnitude scale. These two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly imperceptible or weak and magnitude 7 and over potentially cause serious damage over larger areas, depending on their depth. The largest earthquakes in historic times have been of magnitude slightly over 9, although there is no limit to the possible magnitude. Intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the more damage to structures it causes, all else being equal. At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity. In
its most general sense, the word earthquake is used to
describe any seismic event — whether natural or
caused by humans — that generates seismic waves.
Earthquakes are caused mostly by rupture of geological
faults, but also by other events such as volcanic activity,
landslides, mine blasts, and nuclear tests. An earthquake's
point of initial rupture is called its focus or hypocenter.
The epicenter is the point at ground level directly above
the hypocenter. Floods Flooding may occur as an overflow of water from water bodies, such as a river, lake, or ocean, in which the water overtops or breaks levees, resulting in some of that water escaping its usual boundaries, or it may occur due to an accumulation of rainwater on saturated ground in an areal flood. While the size of a lake or other body of water will vary with seasonal changes in precipitation and snow melt, these changes in size are unlikely to be considered significant unless they flood property or drown domestic animals. Floods can also occur in rivers when the flow rate exceeds the capacity of the river channel, particularly at bends or meanders in the waterway. Floods often cause damage to homes and businesses if they are in the natural flood plains of rivers. While riverine flood damage can be eliminated by moving away from rivers and other bodies of water, people have traditionally lived and worked by rivers because the land is usually flat and fertile and because rivers provide easy travel and access to commerce and industry. Some floods develop slowly, while others such as flash floods, can develop in just a few minutes and without visible signs of rain. Additionally, floods can be local, impacting a neighborhood or community, or very large, affecting entire river basins. |