Monitoring & Early Warning

Monitoring & Early Warning

A drought monitoring and early warning system (DEWS) is the foundation of effective proactive drought policies.  Governments maintain DEWS to warn their citizens and themselves about impending drought conditions.  A DEWS identifies climate and water supply trends and detects the emergence or probability of occurrence and the likely severity of drought and its impacts.  Reliable information must be communicated in a timely manner to water and land managers, policy makers and the public through appropriate communication channels. That information, if used effectively, can be the basis for reducing vulnerability and improving mitigation and response capacities of people and systems at risk.

Effective drought monitoring and early warning  must integrate precipitation and other climatic parameters with water information such as stream flow, snow pack, ground water levels, reservoir and lake levels and soil moisture into a comprehensive assessment of current and future drought and water supply conditions.  In addition, monitoring the impacts (i.e., social indicators) that are occurring on the ground as a drought develops helps calibrate assessments of severity for local areas. This assessment can then trigger appropriate mitigation and response actions that have been identified previously (see pillar 3 on Mitigation, Preparedness and Response).

From: WMO/GWP (2018) and WMO/GWP (2016) Handbook of Drought Indicators and Indices

Examples