Evaluation of a Proposed Channel on Circulation and Morphology Change at Kawaihae Harbor and Pelekane Bay, Hawaii, USA

Abstract

In an effort to improve the water quality and restore marine habitats in Pelekane Bay (PB), installation of a circulation channel was proposed with the intent of enhancing water circulation in PB through Kawaihae Deep Draft Harbor (KDDH) and flushing accumulated sediment out of PB. This study was conducted to investigate the hydraulics and sediment transport consequences of dredging such a channel. The coupled wave, flow, and sediment transport Coastal Modeling System (CMS) was applied during a non-storm and a typical winter (storms) time interval. CMS results were analyzed and compared between existing condition and channel alternatives. It was found that upon reaching PB, incident waves breaking induces higher water level from wave setup, whereas the breakwater at KDDH inhibits depth-limited breaking and setup, creating a differential in water surface elevation (WSE). The water level rise along the channel was calculated to be 0.01-0.03 m, with WSE in PB being higher. The differential wave setup, found for almost all wave conditions, produces water flow from PB to KDDH in the proposed channel. The temporally averaged along-channel current speed is calculated from 0.07 to 0.2 m/sec for the non-storm and storm conditions, respectively. Bay-to-harbor flows will move sediment into the channel, most of which is deposited within 120 m from PB. For the winter storm conditions, the maximum deposition in the channel was calculated to be approximately between 0.7 and 2.0 m among the different alternatives. More sand is deposited under the deeper channel alternatives. The channel or bay blockage appears under all channel alternatives before reaching the end of the simulation.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2010
Accession Number
ADA575178

Entities

People

  • Honghai Li
  • Jessica H. Podoski
  • Mitchell E. Brown
  • Nicholas C. Kraus
  • Thomas D. Smith

Organizations

  • Engineer Research and Development Center

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Channel Flow
  • Coastal Engineering
  • Coral Reefs
  • Engineering
  • Engineers
  • Flow
  • Grain Size
  • Habitats
  • Hydraulics
  • Hydrodynamics
  • Photographs
  • Photography
  • Sedimentation
  • Spatial Distribution
  • Test And Evaluation
  • Topography
  • Water Quality

Fields of Study

  • Environmental science

Readers

  • Coastal Oceanography
  • Coastal and Marine Engineering/Sediment Transport/Hydraulic Engineering
  • Thin Film Deposition Science.