Study on development of method for monitoring of environment relating snow area variations in a wide area of the Yamagata Prefecture using satellite observations

1)与山形县的研究人员组成研究小组，定期召开一系列小组会议。通过会议，讨论了广泛的东北地区雪区信息在花粉传播、森林控制和农业方面的使用。2)通过与山形县公共卫生研究所的合作研究，明确了花粉扩散阶段与积雪分布之间的关系，使我们能够预测扩散阶段。3)提出了利用AVHRR在NOAA卫星上进行雪区探测的先进方法，使定期产生质量控制的雪区结果成为可能。通过这个程序，任何人，甚至是初学者都可以使用卫星图像生成雪域地图。4)采用先进的积雪区探测方法，获得1989-1998年1km空间分辨率的积雪区信息，并将其存储在数据库中。该数据库用于目前与山形县的合作研究，并将用于各种类型的研究。(5) 2001年3 ~ 6月，山形县和其他研究人员实时获取了积雪面积，表明本研究成果可用于业务应用。

1) A research group was formed together with the researchers belonging to the Yamagata Prefecture, and a series of group meeting was held regularly. Through the meetings, usage of the snow area information for the wide Tohoku region has been discussed in the areas of pollen dispersion, forest control and agriculture.2) Through the cooperative research with the Yamagata Prefectural Institute of Public Health, a relationship between the stage of pollen dispersion and the snow distribution become clear, which enable us to forecast the stage of dispersion. This result has been published in the Japanese J. of Palynol.3) The method of snow-area detection using AVHRR on board NOAA satellites is advanced, and it become possible to produce quality-controlled results of the snow area regularly. Thtrough this procedure, anybody, even a beginner can generate the snow-area map using the satellite images.4) Using tne advanced snow-area detection method, information of the snow area with 1km spatial resolution is obtained for 1989-1998, and stored in a database. The database is used in the present cooperative study with the Yamagata Prefecture, and will be used for various type of researches.5)The detected snow area was distributed in real time to the Yamagata prefecture and the other researchers for March to June in 2001, which demonststrated that the present research result can be uaed for operational application.