Drought indices are valuable tools for assessing drought conditions across regions, as they allow for the comparison of anomalies over time and space and they can be calculated over various timescales. The drought portal (https://droogteportaal.nl) is an online platform providing historical, near-real-time and, for some variables, forecasted data on precipitation, evapotranspiration, soil moisture, groundwater, and discharge in the Netherlands. The portal currently features three drought indices: precipitation, precipitation deficit, and groundwater. Drought indices for soil moisture and streamflow are not yet implemented, but they might be added in the future. In order to investigate whether the addition of soil moisture and streamflow drought indices provides additional value, this article outlines the potential of adding the Standardized Soil Moisture Index (SSMI) and the Standardized Streamflow Index (SSI) to the portal as well as the challenges related to data availability and handling missing values.
