DISTRIBUTION OF SALINITY AND TEMPERATURE IN MUSI ESTUARY: USING VERTICAL SALINITY GRADIENT FOR ESTUARY CLASSIFICATION ZONE

Muara Musi merupakan muara sungai Telang dan Musi yang berbatasan langsung dengan Selat Bangka. Pada saat pasang (surut) kita melihat distribusi salinitas meningkat (menurun) yang diketahui melalui distribusi vertikal menggunakan CTD (Conductivity Temperature Depth). Diagram TS (Temperature-Salinity) digunakan untuk melihat karakteristik massa air di daerah penelitian. Metode DIVA (Data-Interpolating Variational Analysis) digunakan untuk interpolasi dan visualisasi data dari data vertikal dan spasial temperatur, salinitas dan densitas. Klasifikasi zona muara Musi diidentifikasi berdasarkan nilai sebaran salinitas yang memperhitungkan pertukaran salinitas yang bersirkulasi pada saat pasang dan surut. Densitas massa air secara signifikan dipengaruhi oleh salinitas yang terbukti bergradasi. Sementara distribusi suhu tidak berubah secara signifikan dengan kedalaman, distribusi spasial menunjukkan bahwa suhu di estuari lebih rendah daripada di daerah hulu dan laut. Distribusi spasial salinitas menunjukkan bahwa salinitas tinggi memasuki muara menuju sungai lebih jauh pada saat pasang dari pada saat surut. Distribusi salinitas berkisar antara 0,5–30 psu dan suhu antara 29–33 ℃ dari bagian horizontal dan vertikal. Pola sebaran salinitas di muara sungai Musi diidentifikasi, terdiri dari tiga zona yang mewakili kondisi salinitas di daerah penelitian, yaitu zona Polyhaline, Mesohaline, dan Olygohaline.Musi estuary is the mouth of the Telang and Musi rivers directly adjacent to the Bangka Strait. During flood (ebb) we see the distribution of salinity increases (decreases) which is known through the vertical distribution using CTD. The TS diagram is used to see the water mass characteristics the study area. Data-Interpolating Variational Analysis (DIVA) method is used to interpolate and visualize data from vertical and spatial temperature, salinity and density data. The classification of the Musi estuary zone is identified based on the value of the distribution of salinity, which considers the exchange of circulating salinity at flood and ebb. The density of the water mass is significantly affected by the proven graded salinity. While the temperature distribution does not change significantly with depth, the spatial distribution indicates that the temperature in the estuary is lower than in the upstream and ocean areas. The spatial distribution of salinity indicates that high salinity enters the estuary towards the river further at flood than at ebb. Salinity distribution ranges from 0.5 to 30 psu and temperatures between 29 and 33 oC from horizontal and vertical sections. The pattern of salinity distribution in the Musi river estuary was identified, consisting of three zones representing salinity conditions in the study area, namely the Polyhaline, Mesohaline, and Olygohaline zones