抄録
Effect of snow on vegetation activity in snowmelt season and after disappearance of snow is analyzed using climate data, snow accumulation-snowmelt model and distributed hydrological model. Vegetation activity is evaluated with NDVI (Normalized Difference Vegetation Index) derived from AVHRR/NOAA data. The Snow accumulation-snowmelt model can estimate snow water equivalence and snowmelt. The distributed hydrological model, which consists of 2 layers (snow and surface) and 2 tanks (soil and ground water), can estimate runoff, soil moisture and so forth.
It is shown that firstly, vegetation activity decreases if the snow water equivalence is higher than 500 mm, secondly, accumulated snowmelt for 10 days is estimated 15 days before from observed day and vegetation is more active if the snowmelt is higher than 20mm, finally, vegetation is more active if the soil wetness index is higher than 70%.
