Palmer Drought Severity Index (PDSI)

The Palmer Drought Severity Index (PDSI) is a tool used to measure long-term drought conditions based on a combination of temperature and rainfall data. It tracks soil moisture levels over time, indicating whether an area is experiencing drought or wet conditions. PDSI values typically range from -4 (extreme drought) to +4 (very wet), helping communities, farmers, and policymakers understand drought severity and make informed decisions. It considers how much moisture has been lost or gained over months, providing a comprehensive view of drought impacts on the environment and water resources.