The UGT roof or flat lysimeter is a highly specialized measuring system for investigating hydrological and ecological processes in the soil layers close to the surface. Like classic lysimeters, the system is ideal for long-term studies under real climatic conditions and enables comparisons between different soil types, different green roof structures, vegetation, or climate scenarios.

Design and equipment

The system consists of a flat, square lysimeter with an area of less than 1 m² up to several square meters, which is mounted on a precise weighing system. It is embedded, for example, in a surrounding greenery or compensation strip, which minimizes the island effect and simulates natural conditions. An integrated UGT Tipping Counter reliably records the amount of seepage water, while customer-specific soil sensors continuously monitor key parameters such as soil moisture, soil temperature, and conductivity. All measurement data is recorded and stored via a UGT data logger. Upon request, the data can be transferred directly online to a data acquisition system.

Fields of application – versatile in research and practice

Shallow-rooted vegetation and green roofs

Thanks to its special design, the lysimeter is particularly suitable for vegetation types with shallow roots, such as mosses, lichens, biological soil crusts, and sedum species. It is often used to study substrates and plantings on green roofs or in urban test areas. The following processes, among others, are analyzed:

• Water balance and evaporation
• Seepage water formation and nutrient leaching
• Pollutant inputs into near-surface soil layers
• Wind erosion studies in semi-arid areas

Urban ecology and climate adaptation

In the context of urban greening and green roofs, the lysimeter provides reliable data for:

• The effectiveness of greening concepts for relieving sewer systems (reducing wastewater costs by verifying actual feed-in quantities)
• Comparative studies of different green roof concepts with regard to evapotranspiration, runoff delay, and runoff reduction

Special application – track bed lysimeter

Adapted as a track bed lysimeter, the system enables the investigation of contamination inputs in traffic areas. This applies to both green and non-green track systems. The data obtained contributes significantly to environmental and water protection in the field of transport infrastructure.