Validation of simulated temperature profiles at rock walls in the eastern alps (Dachstein)

While rock temperature is a key factor for many geomorphic phenomena in high mountains, assessing the small-scale temperature distribution remains challenging. We adapted the program package WUFI (R), originally designed to calculate energy and moisture fluxes in building walls, for modeling natural rock faces. We determined physical rock properties and local meteorological parameters as input data for the simulations at rock walls in the Dachstein Mountains, Austria, and calculated annual temperature fluctuations at the surface and at 3, 10, 30, 50 and 100 cm depth, including different elevations, aspects and slope angles. Thirty-seven temperature sensors inserted into drillholes of different depths at ten locations (altitudes from 2300 to 2700 m) were used to validate the simulation. Additionally, surface temperatures were determined from infrared images; these were calibrated for surface emissivity using further temperature sensors. Simulated temperatures and sensor data show very good agreement, with a mean correlation coefficient of 0.94, and the validation of surface temperatures by thermal imaging also delivered good results (r > 0.9). This means that the WUFI software can be used to model complex temperature distributions in natural rock wall settings, thus making it a valuable tool for geomorphological investigations.