温度植被干旱指数时空融合模型对比

为实时准确地对新疆农业干旱程度进行反演监测，以新疆焉耆盆地为例，通过运用时空自适应反射率融合模型（Spatio Temporal Adaptive Reflectivity Fusion Model，STARFM）、增强型STARFM（Enhanced STARFM，ESTARFM）模型及灵活的时空数据融合模型（Flexible Spatio Temporal Data Fusion，FSDAF）这3种常见的模型对Landsat 8和MODIS数据进行融合，构建了温度植被干旱指数（Temperature Vegetation Dryness Index，TVDI），并采用土壤相对湿度（Relative Soil Moisture，RSM）数据对TVDI反演结果进行了验证。结果表明：①3种数据融合模型所模拟预测的干旱因子（归一化植被指数和地表温度）与真实Landsat 8数据所反演的干旱因子相比，ESTARFM模型模拟预测的干旱因子判定系数（R²）和均方根误差（RMSE）均优于其他两种模型，归一化植被指数（NDVI）的R²和RMSE分别达到了0.924和0.076，地表温度（LST）的R²和RMSE分别达到了0.877和2.799；②3种数据融合模型模拟预测的TVDI通过与真实Landsat 8数据反演的TVDI及RSM数据进行对比验证，发现ESTARFM模型模拟预测的TVDI与上述两种数据之间的R²也均优于其他两种模型，分别达到了0.873和0.248。ESTARFM模型在一定程度上更能准确地模拟预测同时期Landsat 8影像的TVDI分布状况。

Time and Space Fusion Model Comparison of Temperature Vegetation Drought Index

Drought is the first disaster affecting agricultural production. The annual precipitation in Xinjiang of China is scarce and the climate is dry. This is one of the major obstacles to the agricultural transformation and rural revitalization in Xinjiang. Therefore, timely and accurate monitoring of agricultural drought in Xinjiang is of great significance for safeguarding agricultural production. Yanqi Basin in Xinjiang was took as an example. Landsat8 and MODIS data were used. The Spatio Temporal Adaptive Reflectivity Fusion Model (STARFM), the Enhanced STARFM (Enhanced STARFM, ESTARFM) Model and Flexible Spatio Temporal Data Fusion (FSDAF) model were used to construct the Temperature Vegetation Dryness Index (TVDI). At the same time, the Relative Soil Moisture (RSM) was used to verify the TVDI inversion results. The results show that coefficient of determination (R²) and root mean square error (RMSE) of the drought factors(NDVI and surface temperature) simulated by the ESTARFM model were better than that by the other two models. And the R² and RMSE of NDVI simulated by the ESTARFM model reached 0.924 and 0.076. In addition, the R² and RMSE of surface temperature simulated by the ESTARFM model reached 0.877 and 2.799. Comparing with TVDI of the real Landsat8 data inversion and RSM data, it was found that the TVDI simulated by the ESTARFM model is better than the other two models, with 0.873 of R² and 0.248 of RMSE. The ESTARFM model can more accurately simulate the TVDI distribution of the Landsat8 images in the same period, so as to monitor the drought degree of the farmland in Xinjiang.