Title |
Large floods in the United States: where they happen and why |
Creator |
Costa, John E.; O'Connor, Jim E. |
Subject |
Floods; Climatology |
Spatial Coverage |
United States |
Description |
Floods are the most chronic and costly natural hazard in the United States, causing an average of 140 fatalities and $5 billion damage each year (Schildgen, 1999). Despite advances in flood science and implementation of Federal hazard-reduction policies, damage from flooding continues to escalate (Pielke and Downton, 2000). Damage from floods results from a combination of the great power of flowing water and the concentration of people and property along rivers. In the United States, about 3,800 towns and cities of more than 2,500 inhabitants are on floodplains (Miller and Miller, 2000). Damaging floods result when the volume of river flow exceeds levels of flood preparedness, either because flow is greater or longer than expected or because of incomplete understanding of local hazards. Consequently, a primary means of reducing flood hazards is by better understanding the magnitude and likelihood of large flows. The data underlying most studies of flood magnitude and frequency in the United States are records of U.S. Geological Survey (USGS) streamflow gages (fig. 1), which for the last 110 years have been collecting streamflow data at more than 23,000 locations (although not all the streamflow-gaging stations have operated continuously). This circular summarizes the locations and magnitudes of large flows recorded by these gaging stations, showing locations in the United States where relatively large floods occur, and describes, in general terms, some of the climatologic and topographic factors that contribute to large floods. The source of data for this analysis of large U.S. floods is the peak flow files maintained as part of the USGS National Water Information System. These files are maintained for each streamflow-gaging station and include values for the largest instantaneous discharge (peak flow) for each water year (October 1 to September 30) (see for example, fig. 2). As of June 2002, there were records for 23,216 stations on streams of all sizes that together comprise more than a million annual peak flow measurements and estimates. These measurements do not account for or signify the damage caused by floods, but simply indicate the maximum volume of water passing the gaging station during the peak of the flood. |
Publisher |
U.S. Geological Survey |
Date |
2003 |
Type |
Text |
Format |
application/pdf |
Digitization Specifications |
pdf file copied from USGS website (http://pubs.usgs.gov/circ/ ). Uploaded into CONTENTdm version 3.7. |
Identifier |
http://pubs.usgs.gov/circ/2003/circ1245/ |
Source |
Costa, John E. And O'Connor, Jim E., Large floods in the United States: where they happen and why, United States: U.S. Geological Survey Circular 1245, p19. |
Language |
eng |
Rights Management |
Public Domain, Courtesy of the USGS |
Holding Institution |
University of Utah |
ARK |
ark:/87278/s6c24vbz |
Setname |
wwdl_er |
ID |
1145741 |
Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6c24vbz |