Flood volume-duration-frequencies for ungaged rural catchments /
The problem of estimating flood volumes, particularly for extreme recurrence intervals, at ungaged catchments was addressed in this research. The study covers all unregulated, rural catchments in the state of Texas. The study is three-fold in approach. The initial aspect and primary focus of this...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=742161461&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The problem of estimating flood volumes, particularly for extreme recurrence intervals, at ungaged catchments was addressed in this research. The study covers all unregulated, rural catchments in the state of Texas. The study is three-fold in approach. The initial aspect and primary focus of this research was to evaluate and utilize daily mean flow data for flood volume estimation. A pilot study was conducted using 38 watersheds to evaluate the feasibility of such an approach. The results of the pilot study indicated that the daily means are very good estimators of daily volumes and can be used to get fairly representative results. This method was therefore used to estimate and construct a time series of annual maximum flood volumes, for different durations, at all rural, unregulated sites with adequate data, for the entire period of record. Log Pearson Type III distributions were then fitted to the individual time series to estimate flood volumes for various recurrence intervals. These volumes were subsequently regionalized through multiple regression with basin characteristics for the entire state of Texas. The second aspect of this research was the extent of applicability of this methodology. Small watersheds, owing to their shorter response times are often not adequately quantified, in a temporal sense, by the daily means. As such a different approach was needed to address small watersheds. An attempt was made to develop regression equations relating flood volumes as a function of both the hydrograph and basin characteristics. However, flood volumes exhibited very poor correlation with basin characteristics, and fairly good correlation with flood peaks. A peak-volume relationship was therefore developed for small watersheds. The third aspect of this research dealt with trying to establish a boundary between large and small watersheds. Work in this regard focused on both: (a) development of a methodology to better define the boundary; and (b) to quantify the boundary. Although the former objective was achieved, the boundary could not be adequately quantified. Instead, a range was suggested as a possible alternative. |
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| Item Description: | Vita. "Major Subject: Civil Engineering". |
| Physical Description: | x, 116 leaves : illustrations, maps ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |