Flood hazard zones designated as AE or A by the Federal Emergency Management Agency (FEMA)as part of the National Flood Hazard Layer. AE flood zones are areas that present a 1-percent annual chance of flooding and a 26% chance over the life of a 30-year mortgage, according to FEMA. A flood zones are similar but determined by approximate methods of analysis (detailed hydraulic analyses are not performed). Flood zone mapping is complicated by the effects of climate change.