Assessing the Consistency of Remotely Sensed Multiple Drought Indices for Monitoring Drought Phenomena in Continental China

Various drought indices are developed to monitor drought conditions. Each drought index applies to specific environments given its own characteristics. This article aims to compare the drought conditions of continental China detected by remote sensing. We compare diverse types of remote sensing-based indices for studying drought situation in 2017. The Station-based precipitation data with different scales are used to evaluate drought phenomena. The drought indices compared in this article include the precipitation condition index (PCI) derived from tropical rainfall measuring mission data, vegetation condition index (VCI), temperature condition index (TCI) derived from moderate-resolution imaging spectra-radiometer (MODIS) data, and other integrated drought indices, which combine VCI, TCI, and PCI. Vegetation health index (VHI), scaled drought condition index (SDCI), and synthesized drought index (SDI) constitute the integrated drought indices. The results indicate that numerous indices have different applicability across continental China. VHI has the optimal correlation with short-term and long-term precipitation. The SDI, SDCI, VCI, TCI, and temperature-vegetation dryness index (TVDI) are also reliable for monitoring drought conditions and are more suitable for long-term than short-term precipitation. Furthermore, combined indices (VHI, SDI, and SDCI) perform better than single drought indices (PCI, TCI, and VCI). VHI, SDI, and SDCI did not show good consistency in croplands when monitoring agricultural drought.