Sediment Movement on Aligadde Beach, Uttara Kannada District, West Coast of India

Authors

  • P.T. Hanamgond
  • V.C. Chavadi

Keywords:

Beach erosion, India, monsoon, pocket beaches, EOF analysis

Abstract

To understand the erosional and accretional behaviour of Aligadde Beach, monthly measurement of beach profiles over a period of three years (November, 1988 to December, 1991) disclose spatial as well as temporal changes in beach configuration in response to different environmental process variables. In the present study, Empirical Orthogonal Function (EOF) analysis and volume changes have been compared to better understand the on-offshore sediment movement. Monthly observations during November, 1988 to February, 1990 revealed a net gain of 34.6 m3 m-1 in sediment, and the overall for November, 1988 to December. 1991 showed a net gain of 58.0 m3 m-1. During the southwest monsoon season (June-August), however, major loss of sediment was observed. Accumulation or removal of sediment on or offshore is ascribed to waves and tides, and longshore to convergence or reversal of longshore currents. The observed longshore currents revealed reversal trends; i.e., west to east during the southwest monsoon and northeast monsoon seasons and east to west during the rest of the year. The study revealed that the beach morphology undergoes cyclic seasonal changes in response to the changing wind and wave climate in three distinct phases: (1) major erosional phase (seaward sediment movement) during May-August, (2) accretional period (landward sediment movement) during fairweather season, and (3) a minor erosional phase during December-February.


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Published

1993-07-10

Issue

Vol. 9 No. 3 (1993): Journal of Coastal Research

Section

Articles

License

Authorization for personal use is granted by the Coastal Education and Research Foundation [CERF]. By submitting a manuscript, the authors agree that the copyright for their article is transferred to the publisher if the article is accepted for publication. Assignment of copyright is not required, however, from authors who work for organizations which do not permit such assignment, The copyright covers the exclusive rights to reprduce and distribute the article, inclduing reprints, photographic reproductions, microform, or any other reproductions of a similar nature, and translations.