United States customary units are a system of measurements commonly used in the United States. The U.S. customary system developed from English units which were in use in the British Empire before American independence. Consequently most U.S. units are virtually identical to the British imperial units. However, the British system was overhauled in 1824, changing the definitions of some units used there, so several differences exist between the two systems.
The majority of U.S. customary units were redefined in terms of the meter and the kilogram with the Mendenhall Order of 1893, and in practice, for many years before. These definitions were refined by the international yard and pound agreement of 1959. The U.S. primarily uses customary units in its commercial activities, while science, medicine, government, and many sectors of industry use metric units. The International System of Units (SI), the modern form of the metric system, is preferred for many uses by the National Institute of Standards and Technology (NIST).
The system of imperial units or the imperial system (also known as British Imperial) is the system of units first defined in the British Weights and Measures Act of 1824, which was later refined and reduced. The system came into official use across the British Empire. By the late 20th century, most nations of the former empire had officially adopted the metric system as their main system of measurement; however some Imperial units are still used in the United Kingdom and Canada.
A cubic yard is an Imperial / U.S. customary (non-SI non-metric) unit of volume, used in the United States, Canada, and the UK. It is defined as the volume of a cube with sides of 1 yard (3 feet, 36 inches, 0.9144 metres) in length.
The square foot (plural square feet; abbreviated ft² or sq ft) is an imperial unit and U.S. customary unit (non-SI, non-metric) of area, used mainly in the United States, Canada, United Kingdom, Bangladesh, India and Pakistan.]citation needed[ It is defined as the area of a square with sides of 1 foot.
A symbol for square foot, square feet, and "per square foot" commonly used in architecture, real estate and interior space plans is a simple square with a vertical line bisecting it. It is also occasionally written as a square with a slash through it.]citation needed[
The cubic ton is a measure of volume (compare fluid ounce). It is no longer used in the United Kingdom but seems to be still in use in the United States.
A disaster is a natural or man-made (or technological) hazard resulting in an event of substantial extent causing significant physical damage or destruction, loss of life, or drastic change to the environment. A disaster can be ostensively defined as any tragic event stemming from events such as earthquakes, floods, catastrophic accidents, fires, or explosions. It is a phenomenon that can cause damage to life and property and destroy the economic, social and cultural life of people.
In contemporary academia, disasters are seen as the consequence of inappropriately managed risk. These risks are the product of a combination of both hazard/s and vulnerability. Hazards that strike in areas with low vulnerability will never become disasters, as is the case in uninhabited regions.