Challenge
Poznań University of Life Sciences, in cooperation with Tokyo University of Agriculture and Technology, is carrying out a research project funded by the National Science Centre, aimed at gaining a better understanding of how tree canopies affect the structure of rainfall reaching the lower layers of forest ecosystems. The research conducted by Dr Anna Ilek and Dr Kazuki Nanko requires highly precise measurements of the diameter and velocity of raindrops after they pass through tree canopies. An important part of the project is also to compare rainfall characteristics beneath healthy and infected tree canopies and to determine the amount of water reaching the lower layers of the forest.
The key challenge was to create a measurement system capable of supporting advanced measurements directly beneath tree canopies, across multiple locations, and with limited access to power infrastructure. The solution had to ensure high measurement accuracy, easy relocation of research stations, and independent operation under demanding forest microclimate conditions.
Solution
For the purposes of the project, RetencjaPL designed and delivered 7 proprietary mobile measurement platforms, developed specifically for ecohydrological field research. Each platform was equipped with an OTT Parsivel2 laser disdrometer connected to an OTT netDL data logger. During rainfall events, the system records the full drop size and velocity spectrum by measuring the diameter and falling velocity of raindrops passing through the laser beam.
The measurement platforms were designed to enable precise levelling and positioning of the sensor head directly beneath the tree canopy being studied. Their modular design makes them easy to relocate and adapt to different research locations. Due to limited access to electricity in forest environments, an independent power supply system was used, based on rechargeable batteries housed in sealed transport cases and photovoltaic panels that allow the systems to be recharged in the field.
An integral part of the solution is also a dedicated application developed by RetencjaPL, which receives data transmitted continuously from the measurement stations. The system enables automatic data archiving, visualisation, and further analysis. As a result, the project delivered the first mobile measurement system of its kind developed in Poland specifically for advanced ecohydrological research in forest environments.
Benefits
The solution enables the research team to carry out simultaneous, highly precise measurements of rainfall structure at multiple field locations and directly beneath selected tree canopies. The mobility of the platforms and their energy independence significantly increase the flexibility of experimental work and make it possible to use laser disdrometers even in locations without permanent technical infrastructure.
Automatic data recording and transmission reduce the need for manual device operation and streamline the collection and analysis of large measurement datasets. Researchers gain detailed information on rainfall structure, including the size and velocity of individual drops reaching the area beneath tree canopies. The resulting data may contribute to a better understanding of rainfall retention mechanisms in forest stands, more accurate assessment of the water balance of forest areas, and evaluation of how the health condition of tree canopies affects the amount and characteristics of rainfall reaching the soil.
In the longer term, the research results may provide an important source of knowledge supporting the assessment of forest ecosystem resilience to climate change, as well as the planning of adaptation measures and water resource management in forest areas.