Lysimeter Pilot: contributing to understanding the water balance
Reliable monitoring of actual evapotranspiration
What do we see here?
A lysimeter is used to measure the actual evapotranspiration from the soil and the vegetation. This is a demonstration model, but under normal conditions a lysimeter is buried in the ground just below the surface (see Figure 1). A soil column is placed on the weighing system and topped by a vegetation of choice (see Figure 2). By combining the lysimeter with other sensors that for example measure soil moisture, soil suction, groundwater level, temperature and meteorological parameters, one gains a complete picture of the local water balance.
What's this pilot for?
A lysimeter produces valuable information about the actual evapotranspiration, which is frequently the biggest source of water loss that water and land managers have to deal with. Reliable monitoring data on the actual evapotranspiration are therefore very valuable and help provide a good understanding of the water balance. Such field measurements are needed to test the model calculations and interpretations of satellite images, which are used in mapping evapotranspiration in the Netherlands. The monitoring data from lysimeters are also valuable in dealing with water supply issues.
Who is behind this?
The first prototype of this lysimeter was developed by KWR and the Dutch company, Eijkelkamp, Soil & Water (ESW). This was done in a project of the Water Technology programme of the Top Sector Alliance for Knowledge and Innovation (TKI) of the Ministry of Economic Affairs and Climate Policy. ESW itself then further developed the lysimeter into a precise and cost-effective measurement instrument. KWR uses this innovative lysimeter technique in pursuing research objectives in a variety of projects, such as the ‘Smart Roof’ and ‘City Sports’ projects of TKI Water Technology.
