Strong Linkage Between Precipitation Intensity and Monsoon Season Groundwater Recharge in India

Groundwater is a lifeline for millions of people in India, which is affected by the year-to-year variability of precipitation amount and characteristics (low and high intensity). Precipitation intensity has been observed and projected to change in India. However, the crucial impact of precipitation intensity on groundwater recharge in India remains unknown. Here we use in situ data from more than 5,800 groundwater wells to show that precipitation intensity is strongly linked with groundwater recharge in India. In the northwest and north central India, the monsoon season groundwater recharge is linked with the low-intensity precipitation, while in South India high-intensity precipitation is a major driver of groundwater recharge. Observed long-term changes in precipitation characteristics show a decline in the low-intensity rain in the northwest and north central India that are strongly driven by sea surface temperature over the Pacific Ocean. Increases in the high-intensity precipitation in South India are linked with the sea surface temperatures in the Atlantic Ocean. Our results highlight the importance of precipitation intensity for the monsoon season groundwater recharge in India, which can provide insights to sustainably manage rapidly declining groundwater resources in India.