3Druwheidsindices

3Druwheidsindices is a multidimensional drought indicator used in climate and water-resource analysis to provide a unified assessment of drought severity. The index combines three sub-indices that reflect meteorological, agricultural, and hydrological dryness, enabling simultaneous monitoring of different drought aspects across space and time. It is designed to support early warning, risk assessment, and decision making in sectors such as agriculture, water management, and disaster planning.

The three components are the Meteorological Drought Sub-index (MD-SI), the Agricultural Drought Sub-index (AG-SI), and the Hydrological Drought Sub-index (HY-SI). The MD-SI relies on precipitation deficits, temperature and evapotranspiration signals to capture dry spells at the atmospheric level. The AG-SI uses soil moisture status, vegetation health, and crop moisture deficits to reflect impacts on agriculture. The HY-SI incorporates streamflow, groundwater levels, and reservoir storage to represent water resource and hydrological stress. Each sub-index is standardized on a common scale, typically 0 to 1 or 0 to 100, to facilitate integration.

Calculation typically involves aggregating data monthly, normalizing each sub-index against historical climatology, and then combining them through a weighted average or geometric mean. Weights can reflect regional priorities, data availability, or policy objectives, yielding a final 3Druwheidsindices value that summarizes overall drought conditions.

Interpretation centers on severity categories and trend signals. Values close to zero indicate normal conditions, while values near one signal extreme dryness. The index supports monitoring, regional comparison, and scenario analysis, and it is often used in conjunction with other indicators and climate projections to inform agricultural planning and water-resource management. Limitations include data quality, regional calibration needs, and sensitivity to chosen weights.