Stroboscopic photographs of falling snowflakes were analysed to tind relationship between the fall velocity and the shape of their component crystals. The fall velocity depends remarkably upon the dominant shape of component crystals, the size or the mass of snowtlakes, and the surface air temperature. Not all of the empirical formulas of fall velocity are expressed with the exponents of diameters of snowflakes melt. The coefficients of nearly all types of snowflakes have decreasing tendency with inceasing Reynolds numbers.
Differences of snow pressure on partial sloping forms were measured with ferroconcrete piles which have two strain gages on the inside and outside of base portion for three winters 1990/91 to 1992/93 at a snowed forest. The annual maximum snow pressure was 6.4 tons on a concave slope and 3.5 tons on a convex slope. Generally, snow pressure on partial concave slope was twice or more times larger than that on convex slope. It was suggested that planting of cryptomeria trees on partial convex slopes will aid to avoid snow damage to the trees.