Aqueduct Atlas – Flood Occurrence Create Map Title: Description: Basemap Map layers North Direction Map tools Format: Image (PNG) Size: A4 Layout: Landscape Portrait Legend: Left Right None Show all legends +-close300 km200 miLeaflet | © OpenStreetMap contributors. Map Layers Aqueduct Atlas - Flood Occurrence Show news on map '; LEGENDAqueduct Atlas - Flood Occurrence 1. Low (0-1) 2. Low to medium (2-3) 3. Medium to high (4-9) 4. High (10-27) 5. Extremely high (>27) Aqueduct Atlas – Flood OccurrenceFlood Occurrence is the number of floods recorded from 1985 to 2011.