Hydrological Network Design

Minimum Hydrological Stations Density as per WMO

Type of Region Measurement Variable
Density for Minimum NetworkTolerable Density in Difficult Conditions
Flat regions of temperate Mediterranean and tropical zones. 1000-2500 3000-10000
Mountainous regions of temperate, Mediterranean and tropical zones. 300-1000 1000-5000
Small mountainous islands with very irregular precipitations very dense hydrographic network. 140-300 -
Arid and polar zones 5000-20000 -
The detailed Network Design criteria and guidelines are available in the Network Design Manual [Weblink / PDF]