Method of study and cartography of the potential Sunny periods in mountainous areas

TLDR: In this paper, a computerized calculation comparing the apparent movement of the sun and the positions of the summits surrounding a given point, the duration of sunshine at this given point can be calculated for a chosen period of the year.

Abstract: In mountainous areas, the duration of sunny periods is an important but often unknown climatic parameter. The difference in amounts of sunshine between exposed and shade sides of mountains must be treated circumspectly, sometimes corrected, for it is dependent on the action of shadows and thus can sometimes reduce the amount of sunshine at a given spot quite considerably. By using a computerized calculation comparing the apparent movement of the sun and the positions of the summits surrounding a given point, the duration of sunshine at this given point can be calculated for a chosen period of the year. This same calculation repeated for frequent points within a same area is transferred to a grid. This grid can be used to draw maps of the potential amount of sunshine for that area at a precise date or between two given dates. This kind of study can be a valuable aid, not only in research into the environment (the amount of insolation is a determining factor in the melting of snow or ice, the evaporation of lakes, the development of vegetation etc.) but also in the planning of an area (solar energy, exposition of buildings in an urban setting, research into sites for new tourist resorts etc.).