Sains Malaysiana 29:171-185 (2000)                                                                            Sains Fizis dan Gunaan /

Physical and Applied Sciences

Distributions of Temperature and Dissolved Oxygen

in the Terengganu Estuary

Mohd Nasir Saadon & Lim Phaik Kin

Faculty of Applied Science and Technology

Universiti Putra Malaysia Terengganu Mengabang Telipot

21030 Kuala Terengganu

Terengganu Darul Iman, Malaysia

ABSTRACT

This study provides new information on both the temperature and dissolved oxygen (DO) distributions in the Terengganu estuary. Temperature and DO were measured, along the Terengganu estuary and her two rivers, once a month for 12 months, using a Hydrolab multi-parameter probe. This is to determine the response of both temperature and DO distributions to seawater intrusion in the Terengganu estuary. Our results show that water is cooler upstream and the temperature increases downstream towards the mouth of the estuary. The highest water temperature is recorded in June (29.40°C), while the lowest water temperature is detected in January (25.84°C). We concluded that the temperature distribution in Terengganu estuary and both the rivers, is influenced directly by the monsoon seasons. DO values in the Terengganu estuary are generally high (5-6 mg/l) throughout the year except in August (3-4 mg/l). The values tend to increase from the estuary towards the sea from April to July, but the trend reverses from September to December. Therefore, two transitional stages can be identified. The first transitional stage starts from January to March (where seawater gradually intrudes the Terengganu estuary) and the second transitional stage occurs in August (where seawater gradually retreats from the Terengganu estuary). Thus, the DO distribution in the Terengganu estuary and both the rivers is influenced directly by seawater intrusion.

ABSTRAK

Kajian ini memberi maklumat baru tentang taburan suhu dan oksigen terlarut (DO) di dalam Muara Terengganu. Suhu dan DO telah diukur di sepanjang Muara Terengganu dan kedua-dua sungainya, sekali sebulan selama 12 bulan dengan menggunakan 'Hydrolab multi-parameter probe'. Ini bertujuan untuk menentukan tindakbalas taburan suhu dan DO kepada kemasukan air laut ke dalam Muara Terengganu. Keputusan kami menunjukkan air adalah lebih sejuk di hulu sungai dan suhu bertambah menunjukkan ke mulut muara. Suhu air paling tinggi dicatatkan dalam bulan Jun (29.4^oC), sementara suhu air paling rendah dicatatkan dalam bulan Januari (25.84^oC. Kami merumuskan bahawa taburan suhu di dalam Muara Terengganu dan kedua-dua sungainya dipengauhi secara langsung oleh musim monsun. Nilai-nilai DO di dalam Muara Terengganu umumnya  adalah tinggi *5-6 mg/l) sepanjang tahun, kecuali dalam bulan Ogos (3-4 mg/l). Nilai-nilainya bertambah dari hulu muara ke arah laut, dari bulan April hingga Julai tetapi keadaan yang bertentangan berlaku dari bulan September Disember.  Jadi, dua peringkat peralihan dapat dikenalpasti. Peringkat peralihan pertama bermula dari Januari hingga March (di mana air laut masuk secara perlahan-lahan ke dalam Muara Terengganu) dap peringkat peralihan kedua berlaku dalam bulan Ogos (di mana air laut keluara secara perlahan-lahan dari Muara Terenggnau). Oleh itu, taburan DO, di dalam Muara Terengganu dan kedua-dua sungainya, dipengaruhi secara langsung oleh kemasukan air laut.

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