WRRCTR No.156 Measured Evaporation in High Rainfall Areas, Leeward Ko'olau Ranges, O'ahu, Hawai'i

Date
1983-10
Authors
Ekern, Paul C.
Contributor
Advisor
Department
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
Water Resources Research Center, University of Hawaii at Manoa
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
An evaporating surface made from a dark, porous carborundum stone, 6-in. (152.4-rnrn) in diameter, wetted by capillary rise from a plastic reservoir and shielded from rainfall by a clear plastic cover was designed for rainy areas. Class A pan evaporation at five different sites was 0.6 the water loss from corresponding evaporimeters. Water use by Californiagrass was 1.1 pan evaporation and 0.66 the water loss from the evaporimeter. Evaporation, rainfall, and pertinent meteorological factors were measured at one ridge and four valley sites on the Manoa transect in southern Oahu and at one valley and eight ridge sites on the Kipapa Ridge transect on the leeward Koolau Range slopes in central Oahu. Water use on the Kipapa transect was that predicted by the Priestley-Taylor relationship, while water use on the Manoa transect exceeded that predicted with positive advection from the urban surroundings and probable subsidence of the air from the Koolau crest. Measured rates exceeded those from empirical relationships based on extrapolation of pan evaporation measurements. Of the near normal 1981 rainfall of 149 in. (3784.6 mm), runoff was 27%, evaporation 28%, and deep percolate 45% for the Kipapa watershed water balance. Both runoff and evaporation were greater and percolate less than that given for the 1958 water balance. Direct interception of cloud water added an amount less than 2% of the rainfall on the watershed. Maximum short-term, deep percolation rates were no greater than 1.6 in. (40.64 mm)/day and runoff was 0.53 rainfall^1.28.
Description
Keywords
evapotranspiration, pan evaporation, water balance, rainfall, deep percolation, water use, runoff, Priestley-Taylor relationship, Manoa transect, Kipapa transect, Oahu, Hawaii, Evaporation -- Hawaii -- Oahu., Koolau Range (Hawaii), Rain and rainfall -- Hawaii -- Oahu.
Citation
Ekern PC. 1983. Measured evaporation in high rainfall areas, leeward Ko'olau Ranges, O'ahu, Hawai'i. Honolulu (HI): Water Resources Research Center, University of Hawaii at Manoa. WRRC technical report, 156.
Extent
ix + 60 pages
Format
Geographic Location
Time Period
Related To
Table of Contents
Rights
Rights Holder
Local Contexts
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.