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Interactions between warming and wildfires in the last decade in Siberia

过去十年西伯利亚变暖与野火之间的相互作用

基本信息

批准号：
20510001
负责人：
KUSHIDA Keiji
金额：
$ 1.83万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

项目摘要

Siberian wildfires have two burn types : one is stand-replacing fire that burns both forest floor and crown, and the other is surface fire that burns only forest floor. The average carbon-dioxide release during combustion is about 23tC/ha for the stand-replacing fire and 2.3tC/ha for the surface fire. However, the interpretation of these two different fire types through satellite images were hardly studied before. The analyses with the separation of the stand-replacing and surface fires are necessary for estimating carbon-dioxide releases during the combustion and in the forest recovery process. Based on these backgrounds, the algorithm for estimating the fractional land cover areas of the stand-replacing and surface fires and other land categories from the Moderate Resolution Imaging Spectroradiometer (MODIS) was built. The resolution of MODIS is 1km and the observation period is one day. Next, The geographical distributions of the land categories were estimated from MODIS for every m … More onth from May to September in 2002-2010. From the monthly land-category fractional area data, the geographical distributions of the monthly occurrences of stand-replacing fire and surface fire were estimated. The estimation was evaluated by comparing with the fractional areas of the land categories estimated from Landsat TM data. The resolution of Landsat TM is 30m and the observation period is 16 days. The Landsat TM data itself cannot be used for the monthly fire occurrence analysis since the actual observation period is more than two months due to the cloud contamination. By comparing the estimated fire occurrences with meteorological data such as temperature and precipitation, the relationship between the fire occurrence and the climate was analyzed in Siberia. As a result, both the stand-replacing and surface fires have positive correlations with the precipitation. Especially, in the year the areas burnt by both stand-replacing and surface fires were remarkable in the year when the precipitation is remarkably small. Less

西伯利亚野火有两种燃烧类型：一种是林分替代火，燃烧森林地面和树冠，另一种是表面火，只燃烧森林地面。燃烧过程中二氧化碳的平均释放量约为23 tC/公顷的立场取代火和2.3tC/公顷的地面火。然而，这两种不同的火灾类型通过卫星图像的解释，以前几乎没有研究。将林分替换火灾和地表火灾分开进行分析，对于估计燃烧期间和森林恢复过程中的二氧化碳释放量是必要的。在此基础上，建立了利用中分辨率成像光谱仪（MODIS）数据估算林分更新、地表火等土地覆盖面积的算法。MODIS分辨率为1 km，观测周期为1天。其次，利用MODIS数据对每m土地类型的地理分布进行了估计， ...更多信息 2002年至2010年，5月至9月。根据林火和地面火月发生率的地理分布特征，估算了林火和地面火月发生率的地理分布特征。通过与陆地卫星TM数据估计的土地类别的分数面积进行比较，估计进行了评价。Landsat TM分辨率为30 m，观测周期为16 d。由于云污染，Landsat TM数据本身不能用于每月火灾发生分析，因为实际观测周期超过两个月。通过与气温、降水等气象资料的对比，分析了西伯利亚地区火灾发生与气候的关系。结果表明，林分置换和地面火与降水量呈正相关。特别是在降水量显著偏少的年份，林分置换火和地面火的过火面积显著。少