Sains Malaysiana 45(12)(2016): 1843–1848

http://dx.doi.org/10.17576/jsm-2016-4512-08

 

Pemetaan Batimetri Lantai Laut Cetek Delta Sungai Kelantan, Malaysia hingga Pelantar Benua, Laut China Selatan

(Bathymetric Mapping of Shallow Coastal Area of Sungai Kelantan Delta, Malaysia onwards South China Sea Shelf)

 

NURUL AFIFAH MOHD RADZIR*, CHE AZIZ ALI & KAMAL ROSLAN MOHAMED

 

Program Geologi, Pusat Pengajian Sains Sekitaran & Sumber Alam, Fakulti Sains dan Teknologi

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia

 

Received: 4 February 2016/Accepted: 6 June 2016

 

ABSTRAK

Pemetaan dengan menggunakan kaedah pantulan bunyi telah menemukan satu permukaan lantai laut yang unik dengan ciri morfologi yang pelbagai bermula dari kawasan pesisir laut cetek Delta Sungai Kelantan hingga ke pelantar benua Laut China Selatan. Morfologi lantai laut menunjukkan peningkatan sehingga 38 m ke arah pelantar benua. Empat rentasan lantai laut menunjukkan kemiringan yang kurang daripada 1° dengan nilai antara 0.05° dan 0.57°, menunjukkan penurunan yang sekata sehingga pelantar benua. Suatu tindakan mekanisme pencetus telah menyebabkan fenomena lompatan hidraulik berlaku dan membentuk ketakseragaman morfologi lantai laut dan menghasilkan satu lohong hitam sedalam 26 m dari lantai laut sekitarnya dan pembentukan satu beting pasir yang mempunyai ketinggian sehingga 8 m dari permukaan laut dengan keluasan sekitar 9 km2. Penentuan fenomena yang terhasil dikukuhkan dengan penemuan empat kontur tertutup yang dikenal pasti sebagai kaviti kecil di tiga kawasan yang berbeza. Kesemua fitur dan perubahan morfologi yang berlaku di kawasan lantai laut ini terhasil daripada jatuhan air dari mulut Sungai Kelantan yang berterusan dengan kadar kelajuan berbeza bergantung kepada pelepasan air dan musim monsun.

 

Kata kunci: Aliran super-kritikal; aliran tumpat; batimetri; delta Sungai Kelantan; lompatan hidraulik

 

ABSTRACT

Seafloor mapping using sound waves has found a unique landform sea floor with various morphological features vary from shallow coastal area of Sungai Kelantan delta onwards South China Sea shelf. The seafloor morphology was found increasingly to 38 m onwards sea shelf. The four cross sections of the ocean floor found gradient of less than 1° with the value between 0.05° and 0.57°, showing an uneven incline to the continental shelf. An action of a triggering mechanism causes the hydraulic jump phenomenon to affect the seafloor morphology, thus produce black holes as deep as 26 m from the seafloor and a sandbar with height of 8 m above sea level with an area of 9 km2. The phenomenon recognition was confirmed by the four small closed contours known as small craters in the three different places. All the features and morphological changes in the seafloor were setting by the down drift of water from the mouth of Kelantan River continuously with different speed depending on river discharges and climate season.

 

Keywords: Bathymetric; density flow; hydraulic jump; Sungai Kelantan delta; super-critical flow

REFERENCES

Blivi, A. 1993. Geomorphologie et dynamique actuaelle du littoral du Golfe du Benin (Afrique de l’Ouest), English translation. Tesis Ph.D. Universite Michel de Montaigne, Bordeaux (tidak diterbitkan).

Burningham, H. & French, J. 2006. Morphodynamic behavious of a mixed sand-gavel ebb-tidal delta: Deben estuary, Suffolk, UK. Marine Geology 225: 23-44.

Jabatan Parit dan Saliran, Malaysia. 2004-2014. Data taburan hujan dan data kadar aliran air.

Kamal Roslan, M., Che Aziz, A. & Usop, S. 1997. Perubahan dan Perkembangan Morfologi Delta Kelantan. Laporan Penyelidikan UKM S/5/96.

Koopsman, B.N. 1972. Sedimentation in the Kelantan Delta (Malaysia). Sedimentary Geology 7: 65-84.

Muqtada, M.A.K., Ashikin, N.S., Arham, M.A.B. & Izrar, A. 2013. Estimating turbidity and total suspended solids to measure sediment load in Kelantan River. Advanced in Environmental Biology 7(14): 4895-4900.

Raj, J.K. 1982. Net direction and rates of present day beach transport by littoral drift along the East Coast of Peninsular Malaysia. Geological Society of Malaysia Bulletin 15: 57-70.

Wong, P.P. 1981. Beach changes on a monsoon coast, Peninsular Malaysia. Geological Society of Malysia Bulletin 14: 59-74.

Zakaria, A.S. & Jamaluddin, M.J. 1980. The dynamique of Kelantan Coast. Ilmu Alam 9: 17-31.

Zakaria, A.S. 1975. The geomorphology of Kelantan Delta (Malaysia). Catena 2: 337-350.

Zakaria, A.S. 1972a. Sediments of Kelantan Delta: Grain size distribution in different environmental conditions. Nusantara 2: 167-187.

Zakaria, A.S. 1972b. Morphometry of part of Kelantan River catchment. Sains Malaysiana 1(1): 59-76.

 

 

*Corresponding author; email: nurulafifah.mradzir@yahoo.com