HMM-based Drought Index Viewer

The HMM-based index is designed to probabilistically classify a given observation into five drought categories - Dry, Moderate, Severe, Extreme and Exceptional (D0-D4). The viewer creates a graph showing probabilistic classification of drought by HMM and discrete classification of drought by SPI. The precipitation/streamflow data used in estimating drought indices are also plotted. The exact probability for each drought category will be shown in a tooltip window when you hover over it. The drought is classified into five categories, D0-D4, each having a distinct color code. Absence of color indicates a no drought condition.
The following parameters are required:

  • A rain gauge or stream gauge station in Indiana of which you want to see the drought indices
  • Period of interest (as a default, results are arranged in 3 years blocks - for example, 1940-42, 1945-47, etc.)
  • Time window of drought (ranging from 1 to 12 months)