PHENOLOGICAL STAGE MONITORING IN SIBERIA BY USING NOAA/AVHRR DATA

摘要

Phenology describes the seasonal cycle of vegetation functioning. This is essential concept in order to understand the interactions between biosphere, climate, and biogeochemical cycles. This paper proposed a method to derive the start, the maximum, the end, and the length of the vegetation cycle in a year, based on the analysis of time-series of 10-day composite NDVI, NOAA/AVHRR Pathfinder Land Dataset at a resolution of 4 minutes for the year 1982 - 2000. The map of spatial patterns of each phenological s tage are presented, and their zonal distribution is selected in Siberia region, Russia. Thispaper focuses on the start of vegetation growth cycle that is called"onset" date has been related to air temperature summations, which are derived from thermal-time model. A good agreement was found between satellite derived onset and climate predicted onset date and it is expected that onset is used as the indicator to monitor the effects of climate effects. The comprehensive relationship between the NDVI, topography, climate variables and interannual onset date are discussed in terms of major vegetation types.