gigaliter

A gigaliter (GL) is a unit of volume equal to 10^9 liters, or one billion liters. It is used in hydrology, water-resource management, irrigation planning, and large-scale industrial contexts to quantify substantial volumes of water. One gigaliter equals 1,000 megaliters or 1,000,000 cubic meters (m^3).

The liter is a non-SI unit accepted for use with the SI, and the gigaliter is formed by applying the SI prefix giga to the liter. The standard symbol is GL. The term gigalitre is also used in some regions; capitalization may vary (gigaliter vs gigalitre). When writing, readers should ensure consistent units to avoid confusion with other large volumes.

In practice, GL is used to describe reservoir capacities, national or regional water balances, and major irrigation schemes. Because it represents a very large volume, it is less common for daily measurements, where megaliters (ML) or kiloliters (kL) are typically used. For context, a large reservoir or river basin may store tens to hundreds of GL, depending on geography and climate.

See also: megaliter, kiloliter, liter, cubic meter.