# Flood Severity Flood hazard refers to the height in meters of sudden or non normally present appearing water. Flood hazard, in contrast to other natural disasters, is provided with the potential occurrence height (severity) for different return periods (10, 20, 50, 100, 200, 500 years) instead of probabilities of exceeding a threshold. This data layer is a result of processing and aggregating the data sources: * [Global Surface Water](/data-sources/global-surface-water.md) * [Flood Hazard Maps at European and Global Scale](/data-sources/flood-hazard-maps-at-european-and-global-scale.md) * [AgERA5](/data-sources/agera5.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.answr.space/api-data-layers/natural-disasters/flood-severity.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.