What exactly does it mean to live in a 100-year flood plain? Many people misunderstand this to mean the chance of flooding is only once every 100 years, 尽管事实并非如此. This term is actually referring to the 1% chance of a 100-year storm event occurring in any given year. That’s why 100-year floods can happen multiple years in a row, or multiple times in one year. 

But what constitutes a 100-year storm event, and do they always cause a 100-year flood? According to the United States Geological Survey (USGS), 100-year storms are defined by a relationship between rainfall and streamflow, and 100-year storms don’t always cause a 100-year flood. 

例如, the City of Austin says the standard 100-year storm for the city has 24 hours of rainfall and produces a total rainfall of more than 10 inches. 

重要的是, the 100-year flood level can change, 美国地质调查局说, because it is statistically computed using past and existing data, and scientists re-evaluate the frequency of flooding, particularly after significant storm events. 阿特拉斯14号就是这样. 

Atlas 14 is the nationwide study of rainfall intensities, led by the National Oceanic and Atmospheric Administration (NOAA) with additional input from other federal, 状态, 本地实体. Historical rainfall data was collected from 3,900 water gauges and is beneficial in understanding rainfall events and flood risk. Atlas 14 assigns the statistical probable occurrence of 100-year storms and other rainfall frequency events. 

德州2021十大正规彩票app经纪人® magazine explains more about Atlas 14, and how this recent rainfall study will impact further property development in Texas.