Modelled soil moisture

 

The map shows the current drought level in relation to the current field capacity in the root zone depth (in % of the maximum usable field capacity nFc), which is a measure of the amount of water available to plants in the soil, see Notes on the usable field capacity (%nFc).

This index is one of the ones used to calculate the combined drought index.

 

Data basis: Modelled data from the WaSiM hydrological model. The WaSiM hydrological model calculates soil moisture for the whole of Switzerland on the basis of a range of variables such as precipitation, temperature and sunshine duration. The model is used at the Federal Office for the Environment in hydrological field forecasting.

The model projections show possible developments in the future and are subject to uncertainties. They may therefore differ from observations. This is due to simplifications that have to be accepted when creating the model or the model's data basis. This includes, for example, information on land cover and soil properties, which play an important role in calculating soil moisture. An evaluation of the calculated soil moisture is hardly possible due to the lack of areal measurements. In particular, information on soil properties is only available in a coarse resolution.

 

Background information:

Swiss hydrological forecasts (admin.ch) 

Long-term forecasts

 

Note: Switzerland does not yet have a representative monitoring network for soil moisture. To improve the data basis, a network of this kind is to be set up in connection with the introduction of the national drought warning.