Moisture Measurement

Microclimate and rock humidity

In addition to long-term tectonic and lithological conditions, weathering is determined by temperature, humidity and (in dry or structural conditions) the availability of salts. Rock moisture is a central but not sufficiently investigated factor influencing weathering processes both on rock walls and building facades. Sufficient moisture is required for frost weathering, while fluctuations in moisture are the most important factor for salt transport and crystallization. At present, however, there is no reliable and easy-to-use moisture sensor for use in rock and stone areas. We use different humidity measurement methods (mainly electrical resistance, 2D resistance, microwaves, borehole humidity), supplemented by the simulation of humidity fluctuations with the WUFI software.

Publications:

• Rode, M., Schnepfleitner, H. & Sass, O. (2016): Simulation of moisture content in alpine rock walls during freeze-thaw events. Earth surface processes and landforms 41: 1937–1950, DOI: 10.1002/esp.3961
• Sass, O. & Viles, H.A. (2010): Wetting and drying of masonry walls:  2D-resistivity monitoring of driving rain experiments on historic stonework in Oxford, UK. Journal of Applied Geophysics 70: 72-83.
• Sass, O. (2005c): Rock moisture measurements: techniques, results, and implications for weathering. Earth Surface Processes and Landforms 30: 359-347.