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<br />used to reconstruct the largest floods that have occurred during the last 5,000 to 10,000 years,
<br />although the methods can be used for recent and historical flood documentation (Jarrett and
<br />Tomlinson, in press), Paleoflood information may be used along with systematic and historical
<br />hydrologic records to evaluate ext:eme floods, droughts, and the effect of climate change on
<br />hydrologic processes (Kochel and Baker,1982; Jarrett, 1991),
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<br />The Task Committee on Paleoflood Hydrology is preparing a monograph entitled, "Use
<br />of Paleoflood and Historical Data in Water Resources Applications," The purpose of the
<br />monograph is to present paleoflood hydrology as a possible approach for extending hydrologic
<br />records to solve modem water resource problems, The monograph will discuss various types of
<br />hydrologic and paleoflood data, modeling methods, interpretation issues, case studies, and
<br />research needs,
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<br />The monograph will include nine chapters, The first chapter will discuss the need for the
<br />monograph and the potential uses of paleoflood hydrology to solve water resources problems,
<br />The second chapter highlights traditional engineering approaches used in flood hydrology and
<br />introduces basic concepts used in paleoflood hydrology, Chapters 3 and 4 present the various
<br />types of hydrologic and paleoflood data, The field reconnaissance discussion will include
<br />approaches for collecting physical evidence for paleostage indicators and establishing a flood
<br />chronology, Hydraulic modeling and flood frequency analysis will be discussed in Chapter 5,
<br />Chapter 6 will present data and modeling interpretation issues, which will include discussions
<br />about data quality, accuracy, and uncertainty, as well as modeling assumptions, calibration, and
<br />limitations, Several case studies that demonstrate the usefulness of paleoflood data will be
<br />presented in Chapter 7, The last two chapters will discuss the need for further investigations and
<br />present the conclusions and recommendations of the task committee,
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<br />Systematic and Historical Hydrologic Data
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<br />Traditional hydrologic analysis relies on systematic and historical data for estimating
<br />flood frequency relationships and developing design flood hydrographs (lACWD, 1982;
<br />National Research Council, 1999), Systematic data consist of measured streamflow and
<br />precipitation records, Historical data are recorded observations of floods that were made prior to
<br />systematic data collection,
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<br />Streamflow data are usually collected at established gaging stations, although indirect
<br />flood measurements are also available at many other locations, The data generally consist of the
<br />mean flow for various durations and the peak discharge, Hydrographs are available for gaging
<br />stations with continuous recorders, In the United States, streamflow measurements are generally
<br />available at an individual site for about the last 100 years,
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<br />The period of record for precipitation measurements tends to be a little longer than for
<br />streamflow information, The longest records are available at some stations for the last 150 years,
<br />but are generally limited to the last 100 years, Precipitation data are collected by either a
<br />recording or nonrecording gage (Weather Bureau, 1970), A recording gage allows determining
<br />rainfall accumulation for durations as short as a minute,
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