EGU23-7487, updated on 25 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Monitoring of drought in the Netherlands in an online portal 

Marjolein van Huijgevoort1,2, Esther Brakkee1,3, Gé van den Eertwegh4, Erwin Vonk5, Dion van Deijl4, and Ruud Bartholomeus1,6
Marjolein van Huijgevoort et al.
  • 1KWR Water Research Institute, Nieuwegein, The Netherlands
  • 2Institute for Environmental Studies, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
  • 3Physical Geography, Geosciences, Utrecht University, Utrecht, The Netherlands
  • 4KnowH2O, Berg en Dal, The Netherlands
  • 5StellaSpark, Utrecht, The Netherlands
  • 6Soil Physics and Land Management, Wageningen University & Research, Wageningen, The Netherlands

In 2018-2020 water managers in the Netherlands were confronted with extreme drought. This event had a large impact on nature, agriculture, shipping and drinking water supply. To better anticipate dry conditions and improve water management during a drought, up-to-date and accurate information about the meteorological and hydrological situation is crucial. During the 2018 drought it became clear that current information about groundwater levels was scattered across many different organisations. In addition, each organisation had different methods to compare current groundwater levels with historical data to indicate the severity of the drought event. There was a clear need for an uniform indication of drought severity.

We developed an online information portal with up-to-date measurements for precipitation and groundwater levels. To quantify the drought severity, the Standardized Precipitation Index (SPI), Standardized Precipitation-Evapotranspiraton Index (SPEI) and Standardized Groundwater Index (SGI) are determined. The availability of long-term records (30> years) of groundwater observations is limited for most regions in the Netherlands. Therefore, the SGI is based on simulations with a time series model for all locations for the same period (27 years). Time series models are developed for 5818 wells with observations. Several criteria have been applied to evaluate the time series model, for example, a minimum value of the explained variance, resulting in 1931 wells for which SGI values are calculated. We have also compared SGI values directly derived from observations with the SGI values from simulated groundwater levels for locations with longer time periods. This comparison indicated that due to errors or missing values in observations, the SGI values from simulations are more reliable to gain a global overview of the drought situation.

By combining the information on meteorological and hydrological drought in one decision-support system (, water managers and stakeholders can now get an up-to-date overview of the current situation. Due to the uniform determination of drought severity, regions within the Netherlands can be compared. This can help to implement targeted water management decisions for adaptation measures for mitigating drought impacts. Part of the information of the portal is also included in the national drought monitor of Rijkswaterstaat (Dutch Ministry of Infrastructure and Water Management). At the moment, the portal gives forecasted information for 7 days, but the data provides an excellent opportunity to include forecasts on longer timescales ((sub-)seasonal) to improve water management.

How to cite: van Huijgevoort, M., Brakkee, E., van den Eertwegh, G., Vonk, E., van Deijl, D., and Bartholomeus, R.: Monitoring of drought in the Netherlands in an online portal , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7487,, 2023.