Spatiotemporal Comparison of Drought in Shaanxi–Gansu–Ningxia from 2003 to 2020 Using Various Drought Indices in Google Earth Engine

As a common natural disaster, drought can significantly affect the agriculture productivity and human life. Compared to Southeast China, Northwest China is short of water year-round most frequent disaster area in China. Currently, there are still many controversial issues monitoring recent decades. To further understand causes changes we chose Shaanxi, Gansu, Ningxia provinces (SGN) as our study area. We compared spatiotemporal characteristics intensity frequency from 2003 2020 showed by Standardized Precipitation Index (SPI), Vegetation Condition (VCI), Temperature (TCI), Health (VHI), Normalized Supply Water (NVSWI), Soil Moisture (SMCI), Agricultural Drought (SMADI). All these indices wetting trend SGN 2020. The VCI characterization obvious (R2 = 0.9606, p < 0.05): During period 2003–2020, annual average value region increased 28.33 71.61, with growth rate 153.57%. TCI weakest 0.0087), little change region. results Mann–Kendall test indicated that experienced non-significant (p > 0.05) between explore effectiveness different indices, analyzed Pearson correlation each index Palmer Severity (PDSI). PDSI not only consider current supply demand situation but also impact previous dry wet conditions their duration on situation. Using reference, effectively verify performance index. SPI-12 best PDSI, R values greater than 0.6 almost all regions less 0.05 within one-half SMADI had ranging ?0.4~?0.2 regions. this clarified differences frequency, duration, severity continuously reduced; helps us have more comprehensive understanding decades significance for in-depth disasters future.