A disdrometer is an instrument used to measure the drop size distribution and velocity of falling hydrometeors. Some disdrometers can distinguish between rain, graupel, and hail.
A disdrometer in place in the Everglades
Hydrology is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A pr
Rain falling over a drainage basin in Scotland. Understanding the cycling of water into, through, and out of catchments is a key element of hydrology.
The Roman aqueduct at Caesarea Maritima, bringing water from the wetter Carmel mountains to the settlement
A standard NOAA rain gauge
Estimates of changes in water storage around the Tigris and Euphrates Rivers, measured by NASA's GRACE satellites. The satellites measure tiny changes in gravitational acceleration, which can then be processed to reveal movement of water due to changes in its total mass.