Innovative approaches for high precision monitoring of snow cover, Mount Lebanon
Creators: name: ABOU CHAKRA, Charbel
Publisher: name: Zenodo
Year: 2018
Subjects: Snow Height; Agisoft, Time-Lapse Camera; Photogrammetry; Structure-from-Motion; UAV, Total Station; Karst; Water Resource

description: Global climate change induces transformations in rainfall and hydrological regimes in the Mediterranean regions. Lebanon is one of the richest countries in the Middle East for water resources thanks to its mountain ranges that trigger precipitation from the moist air masses coming from the Mediterranean Sea. Snowpack acts as natural water storage in winter and supplies fresh water during spring and summer. Yet, Lebanon is facing a serious water scarcity problem due to: i) the decreasing amount of snow precipitation and climate change; ii) the major growth of the original resident population and the large number of refugees that fled to the country during regional wars. Thus, continuous and systematic monitoring of the Lebanese water resources is becoming crucial. It is therefore very important to investigate low-cost methodologies in terms of both human resources and equipment.Global climate change induces transformations in rainfall and hydrological regimes in the Mediterranean regions. Lebanon is one of the richest countries in the Middle East for water resources thanks to its mountain ranges that trigger precipitation from the moist air masses coming from the Mediterranean Sea. Snowpack acts as natural water storage in winter and supplies fresh water during spring and summer. Yet, Lebanon is facing a serious water scarcity problem due to: i) the decreasing amount of snow precipitation and climate change; ii) the major growth of the original resident population and the large number of refugees that fled to the country during regional wars. Thus, continuous and systematic monitoring of the Lebanese water resources is becoming crucial. It is therefore very important to investigate low-cost methodologies in terms of both human resources and equipment. This research aims to set up an observatory of snow evolution in the pilot sinkhole (2300m a.s.l.) and other sinkholes area (2000m a.s.l) located in Mount Lebanon. Measurements were done using terrestrial (just for a pilot sinkhole) and aerial photogrammetry. Those measurements led to the generation of DEMs, which are validated with total station instruments. Firstly, terrestrial photogrammetry was based on a system that uses three time-lapse cameras and structure-from-motion principles to reconstruct the snow DEMs evolution within the sinkhole. Secondly, aerial photogrammetry missions were done by Phantom DJI[1]. It serves to monitor the pilot sinkhole, extends the study area and monitors other sinkholes area. Thirdly, a total station instrument also serves to fill the gap of observation when terrestrial cameras and drones face any logistical problem. Regarding the observations, more than 40 sites visits were driven. This provides a series of annual and inter-annual snow DEMs that were built, serving to estimate HS, surface, and volume. It was then possible to understand the snowmelt behavior during each year. In addition, those DEMs and volumes provide important information about the trend of the snow cover decrease from year to another. Moreover, they may lead to the approximate prediction of total snowmelt.