Jabarkan Disdrometer - precipitation characteristics dari Hidrologi dalam bahasa sunda

Piezometer - groundwater pressure and, by inference, groundwater depth (see: aquifer test)

Radar - cloud properties, rain rate estimation, hail and snow detection

Rain gauge - rain and snowfall

Satellite - rainy aréa identification, rain rate estimation, land-cover/land-use, soil moisture

Stream gauge - stréam flow (see: discharge (hydrology))

Time domain reflectometer - soil moisture

Observations of hydrologic processes are used to maké predictions of the future behaviour of hydrologic systems (water flow, water quality). One of the major current concerns in hydrologic reséarch is the Prediction in Ungauged Basins (PUB), i.e. in basins where no or only very few data exist.