基于植被再合成指数对农业旱情的适应性分析

Adaptive Analysis of Agricultural Drought Based on Vegetation Re-Synthesis Index

摘要: 以安徽省为研究区，基于MODIS影像去获取植被再合成指数(VI)的关键参数：NDVI和EVI，并应用杨杰等人研究的再合成植被指数算法去合成指数，通过植被再合成指数去反映植被覆盖变化情况，最后与气象干旱指数(SPI)去进行对比验证。研究表明基于NDVI和EVI的植被再合成指数VI在描述植被覆盖在时间和空间维度上的变化敏感。然后通过计算标准化降水指数(SPI)和与VI进行对比分析，发现SPI指数监测的旱情变化与VI所显现的旱情变化一致性较高，最终通过气象报告再与实际情况相对照，发现VI所监测的干旱情况十分符合。

Abstract: Taking Anhui Province as the research area, key parameters of the vegetation resynthesis index (VI), namely NDVI (Normalized Difference Vegetation Index) and EVI (Enhanced Vegetation Index), are obtained by using MODIS images. The resynthesis vegetation index algorithm developed by Yang Jie et al. is applied to synthesize the index. The vegetation re-synthesis index is then used to reflect changes in vegetation cover. Finally, a comparison and validation are performed with the Standardized Precipitation Index (SPI) which represents meteorological drought conditions. The study shows that the vegetation resynthesis index VI based on NDVI and EVI is sensitive in describing changes in vegetation cover in both temporal and spatial dimensions. By comparing the SPI index with VI, it is found that the drought conditions detected by SPI are highly consistent with those indicated by VI. The results are further verified by comparing with actual meteorological reports, confirming that the drought conditions observed by VI are highly accurate.