Sains Ma1aysiana 26(2) 1997: 83-101 Sains Bumi/ Earth Sciences
Perubahan dan Perkembangan Delta Kelantan (Variation and development of the Kelantan Delta)
Kamal Roslan Mohamed, Che Aziz Ali & Uyop Said Jabatan Geologi Fakulti Sains Fizis & Gunaan Universiti Kebangsaan Malaysia 43600 UKM, Bangi, Selangor D.E.
ABSTRAK
Delta Kelantan terletak di pantai timur Semenanjung Malaysia, dan terdedah kepada tindakan ombak yang kuat, terutamanya semasa musim tengkujuh (November hingga Februari) setiap tahun. Walaupun Laut China Selatan mempunyai pengaruh ombak yang kuat, tetapi bentuk Delta Kelantan ini tidak mencirikan delta kuasaan ombak. Delta Kelantan sekarang mempunyai muara berlumpur yang ditumbuhi oleh pokok bakau, dengan banyak alur pengedar kecil. Morfologi delta sekarang menunjukkan pengaruh sungai. Pasang surut, arus persisir dan pengaruh ombak memainkan peranan yang sarna penting dalam perkembangan delta. Sekarang ini sebahagian besar daripada bahagian luar delta dipengaruhi oleh aliran pesisir pantai yang menghasilkan anak tanjung berpasir (sand spit). Kehadiran anak tanjung berpasir secara langsung bertindak melindungi muara daripada tindakan ombak. Ini menyebabkan pengaruh luahan sungai dan pasang surut lebih dominan di bahagian lagun yang terlindung. Secara umumnya, anak tanjung pasir memanjang ke arah barat dengan kadar sehingga melebihi 0.5kmltahun (1988-1990) dan mengalami penghijrahan ke arah selatan mendekati daratan. Dalam lagun pula, pembentukan pulau-pulau lebih pesat, dan berkembang ke arah barat.
ABSTRACT
The Kelantan Delta is located on the east coast of Peninsular Malaysia and it is exposed to the strong waves, particularly during the annual monsoonal season (November to February). Despite the strong waves of the South China Sea, the main features of the Kelantan Delta has no resemblance to other typical wavedominated delta. The present-day Kelantan Delta is influenced by the tide as shown by the dominance of well-developed mangroves in muddy estuaries together with small distributary channels. The tidal, longshore current and wave influences are equally important in the development of the delta. Most of the present-day outer part of the delta is influenced by the longshore current that contributes to the development of sand spits, which indirectly protect the estuaries from wave action. Consequently, the presence of the sand spits have protected the lagoonal areas. Generally, the sand spits are developing towards the west at a rate of over 0.5km/year (1988-1990). An active westward development of smaller islands take place in the lagoons.
RUJUKAN/REFERENCES
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