基于modis数据鲁甸6.5级地震不同烈度区地震前后植被变化研究

为了研究鲁甸6.5级地震不同烈度区地震前后植被的变化,以鲁甸地震完整烈度为研究区,以MODIS产品中的MOD13Q1数据为数据源,通过数据预处理获得2004-2018年不同烈度区年均NDVI时间序列,并用像元二分模型计算得到地震前后的植被覆盖度,从NDVI动态变化、植被覆盖度空间分布特征、植被覆盖度动态变化、植被损毁像元点四个方面分析鲁甸地震不同烈度区地震前后的植被覆盖变化,结论指出:鲁甸地震中地震前后植被覆盖的减少与烈度呈正相关关系,Ⅸ烈度植被损毁现象明显,Ⅵ~Ⅷ植被损毁现象不明显,但通过对不同烈度植被损毁像元点的统计可以得到Ⅵ~Ⅷ烈度植被覆盖的减少与烈度呈正相关关系,烈度越高植被受损面积越大。

Study on Vegetation Changes before and after Earthquakes in Different Intensity Areas of Ludian Earthquake based on Modis Data

In order to study the changes of vegetation before and after the earthquake in different intensity areas of the Ludian earthquake,this paper takes the complete intensity of the Ludian earthquake as the study area,uses the MOD13Q1 data in the MODIS product as the data source,and obtains the average annual NDVI of different intensity from 2004 to 2018 through data preprocessing Time series,and use the dimidiate pixel model to calculate the fractional vegetation coverbefore and after the earthquake.Analyze the changes in vegetation coverage before and after the earthquake in different intensity areas of the Ludian earthquake from four aspects:dynamic changes in NDVI,spatial distribution characteristics of vegetation coverage,dynamic changes in vegetation coverage,and vegetation damage pixel points.The conclusion points out that:the reduction of vegetation coverage before and after the earthquake in Ludian earthquake is positively correlated with the intensity,Ⅸintensity vegetation damage is obvious,Ⅵ~Ⅷvegetation damage is not obvious,However,through the statistics of the pixel points of vegetation damage of different intensities,the reduction ofⅥ~Ⅷintensity vegetation coverage has a positive correlation with the intensity,the higher the intensity,the greater the area of vegetation damage.