基于多种植被指数TVDI京津冀地区干旱监测

Drought Monitoring in Beijing-Tianjin-Hebei Region Based on TVDI of Multiple Vegetation Indexes

以京津冀为研究区,基于MODIS数据产品获取NDVI、EVI、MSAVI及LST,利用DEM对LST进行修正,建立不同植被指数的Ⅵ-Ts特征空间,选取干湿边拟合效果好的植被指数建立TVDI,获取研究区2018年植被生长季(4—10月)干旱情况,利用同步气象站点降水数据进行相关性分析,使用同期气象公报进行结果验证。结果表明:1)利用MSAVI构建的特征空间总体拟合效果优于其他两种植被;TVDIM与同期气象站点降水数据呈显著负相关,均通过P<0.05显著检验。2)空间上,旱情主要发生在张家口和东南平原地区;时间上,旱情表现为先加剧后缓解。综上,TVDIM模型可靠性及精度较高,可用于京津冀地区干旱监测预警。

Take Beijing-Tianjin-Hebei as the research area,obtain NDVI,EVI,MSAVI and LST based on MODIS data products,use DEM to correct LST,establishⅥ-Ts feature space of different vegetation indexes,and select vegetation indexes with good fitting effect on dry and wet edges establish TVDI to obtain the vegetation growth season(April-October)drought conditions in the study area in 2018,use synchronized meteorological station precipitation data for correlation analysis,and use the same period meteorological bulletin to verify the results.The results show that:1)The overall fitting effect of the feature space constructed by MSAVI is better than the other two kinds of vegetation;TVDI M has a significant negative correlation with the precipitation data of meteorological stations in the same period,and both pass the P<0.05 significant test.2)Spatially,droughts mainly occur in Zhangjiakou and the southeast plain;temporally,droughts first intensified and then eased.In summary,the TVDI M model has high reliability and accuracy,and can provide early warning for drought monitoring in the Beijing-Tianjin-Hebei region.