A Modified Temperature Vegetation Dryness Index (mTVDI) for Agricultural Drought Assessment Based on MODIS Data: A Case Study in Northeast China

Satellite-based drought indices have been shown to be effective and convenient in detecting conditions. The temperature vegetation dryness index (TVDI) is one of the most frequently used indices; however, it not suitable for areas with high fractional cover (FVC). In this study, a modified (mTVDI) was constructed by using multispectral (MVDI) proposed PROSAIL simulation water stress experiments which based on theory TVDI utilized MODIS data. Compared TVDI, mTVDI presents more triangular feature space, as well obviously increased R2 values dry wet edges (from 0.37–0.90 0.53–0.91 from 0.00–0.77 0.24–0.80 edges). evaluated standardized precipitation evapotranspiration (SPEIs), precipitation, potential (PET), crop deficit (CWDI), results confirmed that can better reflect actual spatial changes, compared under FVC, presenting an Pearson correlation coefficient (by 0.06–0.10) when SPEIs. Moreover, good performance major events indicates its reliability accuracy monitoring. Overall, reliable accurate satellite-based FVC