Describing and Assessing Drought

Indicators of drought include precipitation, snowpack, streamflow, lake levels, vegetation stress levels, crop production, wildfire events, and more. Scientists gather data about drought indicators from the ground, sky, and space.

A drought index analyzes the relationships between various indicators and computes the results into a format that is easier to understand—typically a numerical value. A drought index is like a final grade for a class that depends on multiple factors (e.g. homework, tests, participation) over time.