Comparison of Drought Characteristics Based on Drought Indices and News Big Data

Drought is a complex natural hazard that develops across different temporal scales and may propagate from meteorological drought to hydrological drought. In addition, the physical characteristics of drought do not necessarily correspond directly to how drought is represented in the news media. This study analyzed meteorological and hydrological drought characteristics at the level of the 17 first-level administrative divisions (provinces) of South Korea and compared them with the frequency of drought-related news articles. The Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), and Streamflow Drought Index (SDI) were calculated at 1-, 3-, 6-, and 12-month timescales using long-term meteorological and streamflow observations. Drought-related news articles published from 2021 to 2025 were retrieved from BIGKinds and processed using explicit cleaning rules, and regions with relatively high frequencies of drought-related news were identified. The spatial agreement between regions with high drought-news frequency and regions with high drought severity derived from each drought index was then evaluated using the top-10 overlap, the Jaccard index, a threshold-based comparison, rank correlation, and permutation tests, and their temporal correspondence was evaluated using monthly rank correlations. In the spatial comparison, the overlap between the top-10 provinces (at most 7 of 10) did not exceed that expected by chance, and this result did not depend on the ranking threshold, the annual aggregation method, the method of counting articles, or normalization by population. In contrast, the monthly number of drought-related articles increased with the number of provinces under drought conditions, most strongly for the 12-month indices (Spearman ρ = 0.42–0.57), and was significantly correlated with the provincial SPI-12 and SPEI-12 values in 8–11 of the 16 provinces. These exploratory results for 2021–2025 suggest that drought-related news coverage follows the temporal evolution of prolonged drought, but that its distribution among provinces cannot be represented by a single drought index or timescale and is only weakly related to the spatial pattern of physical drought severity. News frequency is therefore better interpreted as an indicator of when drought attracts media attention than of where drought is most severe, and its use as complementary information in drought monitoring requires validation against independent drought-impact data.