**3. Research method**

The rationale of the research concept was used with the drought processes observed to have occurred sequentially starting from meteorological drought, agronomical drought, hydrological, to socioeconomical droughts, as indicated in **Figure 3** [18–20]. The concept was further used to create an operational research

**Figure 4.** *Research framework.*

*Hydrological Drought Index Based on Discharge DOI: http://dx.doi.org/10.5772/intechopen.104625*

framework that starts from the preparation of the model through the collection and processing of rainfall, discharge, and climate data of the research location followed by the modeling and verification as well as the calculation of HDI. The model was later applied and tested on the selected watershed as presented in **Figure 4**. The model is built based on historical data in the observation Catchment Area. Then applied to the simulation Catchment Area.
