Definitions for "Drought Index"
In hydrologic terms, computed value which is related to some of the cumulative effects of a prolonged and abnormal moisture deficiency. (An index of hydrological drought corresponding to levels below the mean in streams, lakes, and reservoirs.)
A measure of soil or vegetation dryness.
A number representing the moisture level in duff or upper soil layers. It measures the evaporation, transpiration and precipitation that has occurred.
a numerical scale that scientists use to describe the severity of a drought. Scientists take many kinds of data (like streamflow, rainfall, temperature, and snowpack) and "blend" it into a single number, called a drought index value, to make it easier to understand the drought conditions of a particular area.