Concept for a novel airborne LiDAR system combining high-resolution snow height mapping with co-registered spatial information on the water content of the snowpack

The impact of climate change on snow cover evolution is evident. Increasing amounts of winter precipitation as well as rising temperatures are causing the winter snow cover to change more and more rapidly within one season. To quantify the direct effects on hydrological cycles, spatially and temporally high-resolution information on snow height and the amount of water stored as snow (Snow Water Equivalent, SWE) is required on watershed scales. This paper presents the concept for a novel airborne light detection and ranging (LiDAR) system combining high-resolution snow height mapping with co-registered spatial information on the water content of the snowpack. Based on the optical characteristics of snow, we outline a detailed plan for dual-wavelength LiDAR sensor working at wavelengths of 1030 nm and 515 nm. By comparing the intensities received in the two channels, snow cover parameters like the effective grain size can be inferred. By means of recent snow hydrological models, from these data and the topographic snow depth maps then high resolution SWE maps can be deduced. We supplement our outline with conceptual LiDAR snow depth and reflectance measurements using a commercially available system, pointing out the impact of view angle dependence of received intensity and general applicability for future airborne LiDAR surveys.