Agricultural Drought Dynamics With Satellite Soil Moisture and Impacts on Crop Loss in China During 2003–2022

Agricultural drought poses a significant threat to national food security and regional stability. Understanding its dynamics is essential for effective drought risk management. However, cropland is typically managed at a fine scale, while many previous studies relied on coarseresolution data, limiting their usefulness. To meet the needs of agricultural drought assessment, high-resolution datasets are needed to more accurately capture drought patterns across large areas. This study first calculated the Standardized Soil Moisture Index (SSMI) using a 1 km resolution soil moisture dataset covering China from 2003 to 2022. Then, Mann-Kendall trend analysis and spatiotemporal drought clustering were applied to analyze agricultural drought dynamics. At the national scale, correlation analyses were conducted between SSMI-based and SPEI-based drought intensity and crop loss metrics. Results show that from 2003 to 2022, agricultural drought in China exhibited an overall decreasing trend, with drought event centroids shifting southwest and a declining drought trend in Northeast China. The frequency of drought severity varied spatially: moderate droughts occurred more often in Northeast and Central China, severe droughts mainly in Central China, and extreme droughts were concentrated in southern and southwestern China. Correlations between SSMI-based drought intensity and crop loss indicators were high, with R values of 0.84, 0.77, 0.78, and 0.75 for affected area, disaster area, crop failure area, and food loss respectively, all exceeding those based on SPEI. Future research should integrate SAR data and crop growth indicators to improve drought detection and investigate the interactions between agricultural drought, hydrology, and ecosystems.