Temporal and spatial occurrence of strong winds and large snow load amounts in Finland during 1961-2000

• Main Authors: Gregow, Hilppa, Venäläinen, Ari, Peltola, Heli, Kellomäki, Seppo, Schultz, David
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: Coniferous forest; Precipitation; Snow; Soil frost; Wind climate; Northern Finland
• Online Access: https://research.manchester.ac.uk/en/publications/6c46eeea-5bcc-45ce-bae0-e2dea29d9ca7; https://pure.manchester.ac.uk/ws/files/22313340/POST-PEER-REVIEW-PUBLISHERS.PDF; http://www.metla.fi/silvafennica/full/sf42/sf424515.pdf

Information on the temporal and spatial occurrence of strong winds and snow loads on trees is important for the risk management of wind- and snow-induced damage. Meteorological measurements made at 19 locations across Finland during 1961-2000 are used to understand the temporal and spatial occurrence of strong winds and large snow loads. A Kriging interpolation method was used to produce a spatial analysis of wind-speed events above 11 ms-1, 14 m s -1, and greater or equal to 17 m s-1 and snowfall accumulation above 20 kg m-2 and 30 kg m-2. According to the analysis, wind speeds exceeded 14 m s-1 at least 155 times and reached 17 m s-1 only 5 times at inland locations during the 40 years. Large snowfall accumulations were more frequent in the higher-elevation inland areas than along the coast. The snow load on trees exceeded 20 kg m -2 about 65 times a year when averaged over all 40 years, but was as high as 150 times a year during the mild 1990s. The maximum number of heavy snow-load events occurred in 1994 in northern Finland, consistent with a forest inventory by the Finnish Forest Research Institute in 1992-1994. The findings of this study imply that the risk of wind-induced damage is highest in the late autumn when trees do not have the additional support of frozen soil. In contrast, the risk of snow-induced damage is highest at higher-elevations inland, especially in northern Finland.