Natural Hazards: Causes and Effects - Disaster Management Center ...

Hurricane — in the Western Hemisphere, a major storm with a wind velocity of 75 miles per
hour (120 kilometers per hour) or more. Also called typhoons in the Pacific Ocean, and
cyclones in the Indian Ocean and South Pacific. See Beaufort scale.
Hydrology — the science that studies the land-trapped waters of the earth, their occurrence,
circulation, and distribution; their chemical and physical properties; and their interaction with the
environment, including the relationship to living things.
Hydrometeorology — the study of the occurrence, movement, and changes in the state of water
in the atmosphere. The term is also used in a more restricted sense to mean the study of the
exchange of water between the atmosphere and continental surfaces.
Hypocenter — the location of the focus of an earthquake, calculated by the geographic
coordinates and depth from the surface.
— I —
ICRC — International Committee of the Red Cross
Induced seismicity — earthquake activity resulting from human-made causes such as liquid
intrusion and construction of reservoirs.
In kind — commodity donations given at the time of a disaster; these may consist of food,
blankets, medicines, tents, etc.
Insect infestation — 1) the contamination of harvested or stored stocks by insects, usually
remedied by the use of appropriate insecticides and fumigants; 2) the contamination of a crop
area by insects, which requires the application of insecticides in order to protect crops from
destruction.
Intensity — a subjective measurement of the force of an earthquake at a particular place as
determined by its effects on persons, structures, and earth materials. Intensity is a measure of
effects, while magnitude is a measure of energy. The modified Mercalli scale is the principal
intensity scale used in the United States.
Isobar — a line represented on a map or chart, connecting points on the earth’s surface that
have equal barometric pressure over a given time or period.
Isohyet — a line drawn through geographic points recording equal amounts of precipitation for a
specified period or for a particular storm.
Isoseismal line — a line connecting points on the earth’s surface at which earthquake intensity
is or is expected to be the same.
— K —
Kanamori scale (MW) — a magnitude scale used to measure the seismic energy of great
earthquakes, i.e., earthquakes with rupture lengths greater than 100 kilometers.