Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

West-east Phenological Contrast of Remotely-sensed Vegetation Index (NDVI) and the Climate in Northern Asia

Rikie Suzuki (1), Tomoyuki Nomaki (2), Tetsuzo Yasunari (3)

The phenology of the vegetation over north Asia (mainly over Siberia) and its spatial characteristics were investigated by utilizing remotely-sensed Normalized Difference Vegetation Index (NDVI) data. The analysis was carried out base on weekly NDVI averaged through 3 years (1989 - 1991) using the second generation weekly Global Vegetation Index data set (0.144 x 0.144 spatial resolution). In the NDVI seasonal cycle, three kinds of phenological events, green-up week (NDVI exceeds over 0.2), maximum week, and senescence week (NDVI drops down below 0.2) in a year, were defined at each pixel. Generally, a west-early east-late spatial gradient was found in those three events. In the zonal transect between 45N and 50N , green-up, maximum, and senescence timings around 60E (Kazakh) is about 3, 8, and 14 weeks earlier than those around 110E (Mongolia), respectively. It was suggested that vegetation around Kazakh can flourish during a short time period when the snow thawing water is available from late spring to early summer. While in Mongolia, abundant water is available for the vegetation even in mid summer due to the precipitation. In the 50N - 60N zonal transect, the green-up and maximum around 40E are about 4 to 5 weeks earlier than around 115E. As to the week of senescence, there was not a clear regionality. This west-east phenological contrast was tried to relate to the weekly cumulative temperature (over 0C). It was revealed that the weeks in which the cumulative temperature exceeds over 30C and 120C has quite similar west-east regionality with green-up and maximum weeks regionality of the NDVI, respectively.

Submittal Information

Name : Date :
    Rikie Suzuki
    22-May-01-13:41:11
Organization : Theme :
    Frontier Research System for Global Change
    Theme 4
Address : Presentation :
    c/o National Research Institute for Earth Science and Disaster Prevention, Tennodai 3-1, Tsukuba, Ibaraki 305-0006, Japan
    Poster or oral
Country : Abstract ID :
    Japan
    T4RS22May01134111
Phone : Fax :
    0298-52-1907
    0298-52-1899
E-mail :
    rikie@bosai.go.jp