Record Display for the EPA National Library Catalog


Main Title Instantaneous Unit Hydrograph Analysis of Hawaiian Small Watersheds.
Author Wan, Ru-Yih ; W, I-pai ; La, L. Stephen ;
CORP Author Hawaii Univ., Honolulu. Water Resources Research Center.
Year Published 1970
Report Number TR-42; DI-14-01-0001-1493; OWRR-B-033-HI; 01375,; B-003-HI(2)
Stock Number PB-204 549
Additional Subjects ( Watersheds ; Hawaii) ; ( Surface water runoff ; Hawaii) ; Storms ; Rainfall intensity ; Rivers ; Correlation techniques ; Regression analysis ; Periodic variations ; Drainage ; Deltas ; Flood control ; Stream flow ; Flood forecasting ; Hydrologic cycle(Landforms) ; Precipitation(Meteorology) ; Oahu Island
Library Call Number Additional Info Location Last
NTIS  PB-204 549 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 56p
An analysis of 240 flood hydrographs of 29 small watersheds on Oahu shows some unique hydrologic characteristics. Many of these watersheds are small, some measuring less than 5 square miles, and they have extreme variations in rainfall. Between 4 and 15 single-peak hydrographs were collected for each watershed. The Instantaneous Unit Hydrograph was more adaptable for ocean island conditions such as the Hawaiian Islands, and each individual watershed could be treated by computers. In analyzing these flood hydrographs, hydrologic characteristics such as small area, flush peak, short time to peak, and recession constant, were calculated. Time to peak, which is affected by a combination of storm and watershed characteristics, varied within short distances, as well as between basins. Average rainfall duration ranged from a minimum of 5 minutes to a maximum of 1 hour over a 100 year period. A good correlation was found to exist between effective rainfall duration and the watershed area. (Author)