Electronic Theses and Dissertation

Penelitian ini bertujuan untuk memodelkan parameter kualitas air yaitu oksigen terlarut di perairan Utara Aceh berdasarkan pengaruh pasang surut dan menganalisis distribusi spasial oksigen terlarut di perairan Utara Aceh berdasarkan hasil simulasi numerik. Kajian dilakukan melalui pemodelan numerik arus pasang surut dan sebaran oksigen terlarut dengan menerapkan beberapa skenario suhu permukaan laut. Hasil simulasi menunjukkan bahwa konsentrasi oksigen terlarut di perairan utara Aceh lebih tinggi pada saat pasang (8,45 mg/L) dibandingkan saat surut (6,82 mg/L), yang mengindikasikan penurunan kadar oksigen saat volume air berkurang. Oksigen terlarut lebih tinggi ditemukan di perairan lepas pantai, terutama dekat Selat Malaka dan Samudra Hindia. Hasil pemodelan dengan empat skenario suhu menunjukkan variasi karakteristik sebaran oksigen terlarut. Skenario 1 menghasilkan simulasi paling akurat dengan RMSE 0,743 dan distribusi oksigen stabil sekitar 7-8,45 mg/L. Skenario 2 dan 3 menunjukkan pola ekstrem dengan kadar oksigen >11 mg/L di barat daya saat pasang namun memiliki error lebih tinggi (RMSE 0,837-0,838). Skenario 4 memberikan hasil terburuk dengan kadar oksigen terendah mencapai 6,82 mg/L saat surut dan distribusi tidak merata, terutama di pesisir barat. Penelitian ini juga menemukan bahwa kadar oksigen terlarut di perairan Utara Aceh masih di atas batas baku mutu (>5 mg/L), mencerminkan bahwa kualitas perairan tergolong bagus dalam mendukung ekosistem laut yang ada.
Kata Kunci : Pasang surut, Oksigen Terlarut, Kualitas perairan, Pemodelan Numerik, Perairan Utara Aceh

This study aims to model water quality parameters, namely dissolved oxygen in North Aceh waters based on the influence of tides and analyze the spatial distribution of dissolved oxygen in North Aceh waters based on numerical simulation results. The study was conducted through numerical modeling of tidal currents and dissolved oxygen distribution by applying several sea surface temperature scenarios. The simulation results showed that dissolved oxygen concentrations in northern Aceh waters were higher at high tide (8.45 mg/L) than at low tide (6.82 mg/L), indicating a decrease in oxygen levels as water volume decreases. Higher dissolved oxygen was found in offshore waters, especially near the Malacca Strait and Indian Ocean. Modeling results with four temperature scenarios showed variations in dissolved oxygen distribution characteristics. Scenario 1 produced the most accurate simulation with an RMSE of 0.743 and a stable oxygen distribution of around 7-8.45 mg/L. Scenarios 2 and 3 showed extreme patterns with oxygen levels >11 mg/L in the southwest at high tide but had higher errors (RMSE 0.837-0.838). Scenario 4 gave the worst results with the lowest oxygen levels reaching 6.82 mg/L at low tide and uneven distribution, especially on the west coast. This study also found that dissolved oxygen levels in North Aceh waters are still above the quality limit (>5 mg/L), reflecting that the water quality is relatively good in supporting existing marine ecosystems. Keywords : Tides, Dissolved Oxygen, Water quality, Numerical Modeling, North Aceh Waters