Damien Roth: Analyse microclimatique du Vallon de Nant

Damien Roth
Co-supervisors: Prof. Michel Jayboyedoff, Pascal Horton, Jean-Michel Fallot

This paper aims to treat and analyze a data set coming from four weather stations setup by Lausanne University’s IGAR (Institut de Géomatique et d’Analyse du Risque) in Prealps, within the Vallon de Nant.

This work has two main goals:

  • Processing the data set of all four stations from the 19th of December 2007, setup date of the first station, to the 15th of August 2010.
  •  Analyzing temperature data coupled with wind data, azimuth and speed, in order to understand the peculiarity of observed phenomena.

Processing and pooling the data set was performed using Matlab®, which enabled better availability of data for analysis. Processing allowed us to exclude outlying values from the data set and brought to light a few temporal problems in the data set of several stations. It also made us aware that some data contained in the stations database were actually coming from another site.

The analysis’ aim to understand the phenomena happening within the Vallon de Nant showed several temperature inversions, mostly at low altitudes, as well as wind direction changes which we couldn’t fully explain. It also highlighted the difficulties that some precipitation sensors experience at high altitudes and in harsh winter conditions.