Assessment of forest fire seasonality using MODIS fire potential: A time seri...

雩风三日

Assessment of forest fire seasonality using MODIS fire potential:A time series approach
利用MODIS火灾潜力评估森林火灾的季节性：时间序列方法

      We utilized Fire Potential Index (FPI) to assess quantitatively fire season in a Mediterranean and a Temperate ecoregion of Iberian Peninsula by means of Time Series Analysis. The FPI was derived using MODIS NDWI and NDVI time series as indicators of vegetation status. Temperature and relative humidity time series from meteorological stations were interpolated using Universal Kriging. The average FPI time series were computed for each ecoregion for the period running from January 2001 to December 2005 and Time Series Analysis was applied to these series. Results show that FPINDWI and FPINDVI were able to describe fire season in two different ecoregions. Using Time Series Analysis was possible to evaluate and model fire dynamics. By means of spectral analysis and autoregressive models it was possible to detect hidden periodic components and model FPI dynamics with previous FPI information. Large differences between the Mediterranean and the Temperate ecoregions were demonstrated and subtle variability in the Temperate region could be explained. This quantitative approach represents an operational new tool for assessing subtle variations in fire season due to climate change.
     通过时间序列分析，我们利用火灾潜力指数（FPI）定量评估了伊比利亚半岛地中海和温带生态区的火灾季节。 FPI是使用MODIS NDWI和NDVI时间序列作为植被状况指标得出的。使用通用克里格插值法对来自气象站的温度和相对湿度时间序列进行插值。计算了每个生态区2001年1月至2005年12月期间的平均FPI时间序列，并将时间序列分析应用于这些序列。结果表明FPINDWI和FPINDVI能够描述两个不同生态区域的火灾季节。使用时间序列分析可以评估和模拟火灾动态。通过频谱分析和自回归模型，可以检测隐藏的周期性成分，并使用先前的FPI信息对FPI动态进行建模。证明了地中海和温带生态区之间的巨大差异，并可以解释温带区的细微变化。这种定量方法代表了用于评估由于气候变化引起的火灾季节细微变化的可操作新工具。

Keywords:Fire Potential Index;Fire season;NDVI;NDWI;Time Series Analysis;Universal Kriging;
关键字：火势指数;火季;NDVI;NDWI;时间序列分析;通用克里格