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Monitoring & Early Warning

IDMP Guidelines and tools

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 (not yet published) and WMO/GWP (2016) Handbook of Drought Indicators and Indices



CoverageDrought productDrought indicator/index
GlobalGlobal Drought Information SystemStandardized Precipitation Index (SPI),
Vegetation Health Index (VHI)
GlobalFAO's Agricultural Stress Index System (ASIS)Agricultural Stress Index (ASI)
GlobalOngoing droughts monitored by Relief WebImpact reports
GlobalFamine Early Warning System Network, i.e. not strictly a drought productEvidence-based analysis on food security
AfricaAfrican Flood and Drought MonitorStandardized Precipitation Index (SPI),
Normalized Difference Vegetation Index (NDVI),
Drought Index,
Streamflow Percentile
Latin AmericaLatin America Flood and Drought MonitorStandardized Precipitation Index (SPI),
Normalized Difference Vegetation Index (NDVI),
Drought Index,
Streamflow Percentile
North AmericaNorth American Drought MonitorStandardized Precipitation Index (SPI),
Percent of Average Precipitation,
Palmer Drought Index
South AsiaSouth Asia Drought Monitoring System (SADMS)Integrated Drought Severity Index (IDSI),
Standardized Precipitation Index (SPI),
Soil Moisture Index,
Vegetation Condition Index (VCI),
Temperature Condition Index (TCI),
Precipitation Condition Index (PCI)
The CaribbeanCaribbean Drought BulletinStandardized Precipitation Index (SPI)
EuropeEuropean Drought ObservatoryCombined Drought Indicator (CDI),
Standardized Precipitation Index (SPI),
Soil Moisture Anomaly (SMA),
Vegetation Productivity Anomaly (fAPAR Anomaly)
Southeastern EuropeDrought Management Center for Southeastern Europe (DMCSEE): Drought Bulletins and MapsStandardized Precipitation Index (SPI)
ArgentinaStandardized Precipitation Index (SPI)Standardized Precipitation Index (SPI)
AustraliaDrought reportRainfall deficiencies,
Soil moisture
BangladeshDrought monitoringStandardized Precipitation Index (SPI),
Temperature Deviation
BelizeDrought MonitoringStandardized Precipitation Index (SPI)
BoliviaMonthly agrometeorological bulletinVegetation Health Index (VHI),
Agricultural Stress Index (ASI)
BrazilStandardized Precipitation Index (SPI)Standardized Precipitation Index (SPI)
BrazilAgroclimatiological Bulletin MapsWater Balance
Northeastern BrazilNortheast Brazil Drought Monitor
CanadaCanadian Drought MonitorPrecipitation and temperature indicators,
Normalized Difference Vegetation Index (NDVI),
Streamflow values,
Palmer Drought Index (PDI) ,
Standardized Precipitation Index (SPI),
Drought indicators used by the agriculture, forestry, and water management sectors,
Climate data
ChileDrought MonitorObserved Precipitation DGA,
Observed Precipitation RAN,
Standardized Precipitation Index (SPI),
Observed Temperature RAN
ChinaDrought Observations
ColombiaMonthly drought indexStandardized Precipitation Index (SPI)
CroatiaDrought monitoringCumulative precipitation amount,
Difference between measured and average precipitation,
Ratio between measured and average precipitation,
Standardized Precipitation Index (SPI),
Percentile for measured precipitation,
Return period for measured precipitation
CubaAgricultural drought
Czech RepublicHydrometerological, climate and soil droughtModel soil moisture,
EcuadorAgrometeorological informationStandardized Precipitation Index (SPI),
Soil moisture
GermanyStandardized Precipitation Index (SPI); Climatological maps of GermanyStandardized Precipitation Index (SPI),
Aridity Index,
Water Balance
HungaryAgrometeorologySoil moisture,
Normalized Difference Vegetation Index (NDVI)
IndiaDrought MonitoringAridity Anomaly Index (AAI),
Standardized Precipitation Index (SPI)
IndonesiaStandardized Precipitation Index (SPI)Standardized Precipitation Index (SPI)
IrelandAgricultural ReportsSoil Moisture Deficits,
Air temperature,
Soil temperature,
ItalyDrought bulletinStandardized Precipitation Index (SPI)
JamaicaDrought Forecast Map; Farmers BulletinStandardized Precipitation Index (SPI)
MexicoDrought Monitoring in MexicoStandardized Precipitation Index (SPI),
Percent of Normal Precipitation,
Vegetation Health Index (VHI),
Soil Moisture Leaky Bucket CPC-NOAA Model,
Normalized Difference Vegetation Index (NDVI),
Average Temperature Anomaly,
Water Availability Percentage
MongoliaMODIS product-Drought
MontenegroDrought Monitoring - SPI indexStandardized Precipitation Index (SPI)
MyanmarAgro-Met BulletinPrecipitation,
Soil Moisture
New ZealandNew Zealand Drought Monitor; Daily climate mapsSoil Moisture Deficit,
Soil Moisture Anomaly,
Standardized Precipitation Index (SPI)
NicaraguaAgrometeorological BulletinAgricultural Stress Index (ASI),
Soil moisture
NigeriaDrought and Flood Monitoring BulletinStandardized Precipitation Index (SPI)
PakistanDrought Watch BulletinPercentage Departure of Rainfall, Standardized Precipitation Index (SPI), Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST), Temperature Vegetation Dryness Index (TVDI)
PanamaStandardized Precipitation Index (SPI)Standardized Precipitation Index (SPI)
Papua New GuineaDrought MonitoringConsecutive Dry Days (CDD),
Dry spell (DS),
Wet spell (WS)
ParaguayAgrometeorological BulletinWater balance,
Standardized Precipitation Index (SPI)
PeruDrought MonitorStandardized Precipitation Index (SPI),
Reservoirs levels,
Normalized Difference Vegetation Index (NDVI),
Water balance,
Combined Drought Indicator (CDI)
PolandAgricultural Drought Monitoring System (ADMS)Climatic water balance
PortugalDrought Monitoring - SPI IndexStandardized Precipitation Index (SPI)
SerbiaMoisture conditions and drought monitoringStandardized Precipitation Index (SPI)
SlovakiaDrought MonitoringStandardized Precipitation Index (SPI),
Standardized Precipitation Evapotranspiration Index (SPEI),
Crop Moisture Index (CMI)
SloveniaStandardized Precipitation Index (SPI)Standardized Precipitation Index (SPI)
South AfricaUMLINDI - Agrometeorological bulletinRainfall,
Standardized Precipitation Index (SPI),
Rainfall Deciles,
Water balance,
Standardized Difference Vegetation Index (SDVI),
Normalized Difference Vegetation Index (NDVI),
Vegetation Condition Index (VCI)
South AfricaNational Integrated Water Information System - Drought status and managementDam levels,
Standardized Precipitation Index (SPI)
SpainMeteorological Drought MonitoringStandardized Precipitation Index (SPI)
SwitzerlandDrought indicesStandardized Precipitation Index (SPI),
Standardized Precipitation Evapotranspiration Index (SPEI),
Water balance,
Soil moisture,
Soil water deficit,
Vegetation water deficit,
Agricultural Reference Index for Drought (ARID)
TurkeyMeteorological Drought Situation according to Standardized Precipitation Index MethodStandardized Precipitation Index (SPI)
UKUK Drought PortalStandardized Precipitation Index (SPI)
UruguayStandardized Precipitation Index (SPI)Standardized Precipitation Index (SPI)
USAUnited States Drought MonitorPalmer Drought Severity Index (PDSI),
CPC Soil Moisture Model (Percentiles),
USGS Weekly Streamflow (Percentiles),
Standardized Precipitation Index (SPI),
Objective Drought Indicator Blends (Percentiles)
VenezuelaDrought MonitoringStandardized Precipitation Index (SPI)