Monitoring the Snowpack Volume in a Sinkhole on Mount Lebanon using Time Lapse Photogrammetry

C. Abou Chakra , Simon Gascoin (1) , J. Somma (2) , Pascal Fanise (1) , Laurent Drapeau (1)

1 CESBIO - Centre d'études spatiales de la biosphère
2 Laboratoire de Télédétection, Département de Géographie

Lebanon has experienced serious water scarcity issues recently, despite being one of the wealthiest countries in the Middle East for water resources. A large fraction of the water resources originates from the melting of the seasonal snow on Mount Lebanon. Therefore, continuous and systematic monitoring of the Lebanese snowpack is becoming crucial. The top of Mount Lebanon is punctuated by karstic hollows named sinkholes, which play a key role in the hydrological regime as natural snow reservoirs. However, monitoring these natural snow reservoirs remains challenging using traditional in situ and remote sensing techniques. Here, we present a new system in monitoring the evolution of the snowpack volume in a pilot sinkhole located in Mount Lebanon. The system uses three compact time-lapse cameras and photogrammetric software to reconstruct the elevation of the snow surface within the sinkhole. The approach is validated by standard topographic surveys. The results indicate that the snow height can be retrieved with an accuracy between 20 and 60 cm (residuals standard deviation) and a low bias of 50 cm after co-registration of the digital elevation models. This system can be used to derive the snowpack volume in the sinkhole on a daily basis at low cost.

Mots clés: water resource; snow; time-lapse camera; photogrammetry; structure-from-motion; water resource

Domaines: Interfaces continentales, environnement

C. Abou Chakra, Simon Gascoin, J. Somma, Pascal Fanise, Laurent Drapeau. Monitoring the Snowpack Volume in a Sinkhole on Mount Lebanon using Time Lapse Photogrammetry. Sensors, 2019, 19 (18), pp.1-16. ⟨10.3390/s19183890⟩. ⟨hal-02351618⟩