In order to determine the influence of various factors on flash flooding, six case studies during which flash flooding occurred across central North Carolina are examined: 1) 26 August 2002, 2) 11 October 2002, 3) 9-10 April 2003, 4) 16 June 2003, 5) 29 July 2003, and 6) 9 August 2003. Utilizing stream gage data from the United States Geological Survey combined with radar-estimated precipitation from the Weather Surveillance Radar-1988 Doppler (WSR-88D) KRAX near Clayton, NC, several statistical conclusions are drawn. These conclusions are based on relationships between the inputs ? rain rate and precipitation amount ? to the stream responses: the amount of time between when the stream began its rise and when the maximum stage was reached, the amount of time between the onset of precipitation and the initial response of the stream, the maximum stage reached, the change in height of the stream, and the rate of change of height of the stream. Results indicate that precipitation rate and amount tend to dominate the influence of stream response; however, in many situations, land-surface characteristics play an important role. The notable situations where precipitation rate and amount do not dominate are along the major rivers, in locations with sandy soils where infiltration is high, and in urban areas, where runoff occurs rapidly and streams thus respond quickly regardless of precipitation rate or amount. In addition, rain rate and precipitation amount do not necessarily have similar relationships with the stream response variables; rain rate has a stronger correlation with rate of change of stream rise, while precipitation amount has a stronger correlation with change in stream height. However, it is not enough to study rainfall rates and precipitation amounts if a flash flood warning is to be issued. The results of this research show that there is value and necessity in understanding the role of land-surface characteristics when determining if flash flooding is going to occur.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-08122004-004241 |
| Date | 05 November 2004 |
| Creators | Palmer, Trisha Denise |
| Contributors | Dr. Sethu Raman, Kermit Keeter, Dr. Allen J. Riordan, Dr. Gary M. Lackmann |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-08122004-004241/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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