GDO Standardized Precipitation Index JRA-3Q, 48-month accumulation period (SPI-48) (version 1.0.0)

The 48-month Standardized Precipitation Index (SPI-48) is an indicator used to monitor meteorological drought based on precipitation anomalies over 48-month accumulation periods. SPI-48 serves as a proxy indicator for long-term impacts, such as reduced reservoir and groundwater recharge. The input data for calculating the SPI-48 is JRA-3Q precipitation reanalysis (Japanese Reanalysis for Three Quarters of a Century, by Japan Meteorological Agency (JMA; https://jra.kishou.go.jp/JRA-3Q/index_en.html).