scholarly journals Pemetaan Kedalaman Laut Menggunakan Multibeam Echosounder, (MB1) di Perairan Punggur, Kepri

2021 ◽  
Vol 13 (1) ◽  
pp. 84-92
Author(s):  
Dodi Prima Resda ◽  
Muhammad Zainuddin Lubis ◽  
Dirgan Timbang
Keyword(s):  
Continental Shelf ◽  
Sea Level ◽  
Mean Sea Level ◽  
Multibeam Echosounder ◽  
Diurnal Tides

Penelitian ini dilakukan pada bulan April 2018 di perairan Punggur untuk melakukan penelitian ini dilakukan menggunakan metode survei batimetri dan pasut bertujuan mendapatkan informasi kedalaman dan posisi di perairan Punggur yang berperan untuk mendukung aktifitas di sekitar perairan Punggur. Penelitian ini dilakukan dengan melakukan pemeruman menggunakan intrumen Multibeam Echosounder (MBES) System. Pasang surut mengetahui dinamika atau perubahan permukaan laut dengan demikian maka di lakukan survei batimetri dan survei pasang surut secara bersamaan yaitu pasang surut pada kegiatan survei batimetri bertujuan sebagai bidang acuan kedalaman untuk menentukan jenis/tipe Pasut dan ketinggian muka air laut rata-rata MSL(Mean Sea Level) sebagai titik referensi (titik nol) untuk pengukuran elevasi. Nilai Formzahl diketahui nilai besaran bilangan Formzahl adalah 1,35 Sehingga tipe pasut pada Perairan sekitaran pelabuhan yaitu tipe campuran condong ganda (Mixed mainly diurnal tides). Hasil pengukuran batimetri yang telah di koreksi dengan nilai MSL 1,35 meter yang menghasilkan akurasi pada nilai kedalaman. Hal ini menunjukkan dengan adanya perubahan nilai kedalaman di perairan punggur, Batam. Hasil penelitian menunjukan nilai kedalaman di perairan punggur berkisar antara 16 sampai 25 meter di bawah permukaan laut, sehingga nilai kedalaman atau batimetri di perairan tersebut tidak termasuk berada di daerah continental shelf yang menjelaskan dengan adanya nilai topografi landai. Kata kunci:  Batimetri, Perairan Punggur, Pasang Surut, Multibeam Echosounder (MBES)

scholarly journals PROSES ABRASI DI KAWASAN PANTAI LOMBONG, MAJENE, SULAWESI BARAT

2016 ◽  
Vol 9 (3) ◽  
pp. 159
Author(s):  
Yudhicara Yudhicara ◽  
Mira Yossy
Keyword(s):  
Data Analysis ◽  
Sea Level ◽  
Wind Direction ◽  
Field Work ◽  
Tidal Range ◽  
Horizontal Distance ◽  
Mean Sea Level ◽  
Tidal Data ◽  
Wave Flux ◽  
Diurnal Tides

Saat ini pantai Lombong yang merupakan bagian dari kawasan pantai di Kecamatan Malunda, Kabupaten Majene, Sulawesi Barat mengalami kerusakan akibat abrasi, sehingga sarana dan prasarana umum di beberapa tempat terancam mengalami kerusakan. Untuk itu dilakukan analisis terhadap potensi abrasi melalui suatu penelitian, berupa kegiatan lapangan dan analisis yang antara lain adalah analisis energi fluks gelombang menggunakan data arah dan kecepatan angin; analisis material endapan pantai; analisis arus sepanjang pantai; serta analisis data pasang surut. Berdasarkan hasil pengukuran di atas, beda tinggi dataran pantai tempat pemukiman berada relatif sangat landai (0.2-1.0 m) dengan jarak yang sangat dekat terhadap garis pantai yaitu 18 hingga 52 m. Hasil analisis data angin menunjukkan bahwa arah angin dominan yang dapat memicu timbulnya gelombang di perairan Majene, adalah angin yang berasal dari arah barat (18,11 %) dan angin barat laut (17,41 %). Tinggi gelombang dari arah barat dan barat laut relatif lebih tinggi dibandingkan dengan dari arah lainnya, karena arah ini mempunyai kecepatan dan panjang fetch angin yang lebih besar. Analisis data pasang surut memunjukkan bahwa rentang air di perairan Majene ini adalah 170 cm dengan tinggi duduk tengah muka laut (MSL) 89.99 cm, sedangkan dari perhitungan konstanta harmonik mengidentifikasikan bahwa tipe pasang surut di perairan Majene tersebut adalah tipe campuran condong harian tunggal (mixed mainly diurnal tides). Berdasarkan hasil perhitungan energi fluks, terlihat bahwa daerah-daerah yang berpotensi mengalami proses abrasi adalah di titik amat 1 - 2; 6 - 13; 14 - 17; 19 - 21, sedangkan pantai yang berpotensi mengalami sedimentasi adalah pada titik amat 2 – 3; 13 – 14; 17 – 19. Titik amat 3 – 6 dan 21 – 22 relatif stabil. Kata kunci: Pantai Lombong, Abrasi, Gelombang, Angin, Pasang surut Currently, the coastal area of Lombong as part of Malunda sub district, Majene, West Sulawesi has suffered damage caused by abrasion and some places has threatened damaged on public facilities and infrastructure. This is the reason why the study of abrasion potential has been conducted. We did some analysis, such as wave flux energy by using wind direction and velocity; coastal sediment material; longshore current and tidal data analysis beside the field work. Study result indicate that the coastal plain height different is about 0.2 to 1.0 m in term of mean sea level, and the horizontal distance of 18-52 m of the nearest building from the shoreline. Wind analysis result obtained that the dominant wind direction that could lead to a wave in Majene waters are winds coming from the west (18.11%) and northwest (17.41 %) which is relatively higher compared to other direction, which has long fetch and greater wind speed. Tidal data analysis showed that the tidal range in Majene waters is 170 cm and mean sea level is 89.99 cm. According to the harmonic constant calculation that identify the type of tide in Majene waters is mixed mainly diurnal tides. calculation on energi flux reveal that areas which are potentially experiencing on abrasion process are at locations between points of 1 to 2; 6 to13; and 14 to 17, while areas which are potentially experiencing sedimentation are at locations between points 2 to 3; 13 to 14; and 17 to 19, and points 3 to 6 and 21 to 22 are relatively stable. Key words: Lombong beach, abrassion, waves, winds, tides.

PEMUTAKHIRAN DIGITAL ELEVATION MODEL NASIONAL WILAYAH LAUT (Studi Kasus: Wilayah Perairan Aceh)

2021 ◽  
pp. 699
Author(s):  
Teguh Sulistian ◽  
Sandi Aditya ◽  
Fajar Triady Mugiarto ◽  
Fatichatus Istighfarini ◽  
Rifqi Muhammad Harrys ◽  
...  
Keyword(s):  
Sea Level ◽  
Digital Elevation Model ◽  
Mean Sea Level ◽  
Multibeam Echosounder ◽  
Digital Elevation ◽  
Elevation Model

Badan Informasi Geospasial (BIG) telah mempublikasikan Seamless Digital Elevation Model Nasional (DEMNAS) pada tahun 2018. DEMNAS terdiri dari 2 model elevasi yaitu DEMNAS di wilayah darat dengan resolusi spasial 0,27 arc-second dan DEMNAS di wilayah laut atau lebih sering disebut dengan Batimetri Nasional (BATNAS) dengan resolusi spasial 6 arc-second. Tujuan penelitian ini adalah pemutakhiran data DEMNAS wilayah laut dari resolusi spasial 6 arc-second menuju resolusi spasial 2 arc-second dengan menggunakan metode interpolasi spline. Data yang digunakan dalam penelitian ini meliputi data pemeruman singlebeam echosounder (SBES), data pemeruman multibeam echosounder (MBES) dan data satelit altimetri. Data utama yang digunakan merupakan hasil pemeruman dari berbagai instansi yang menjadi kontributor pada program BATNAS. Proses pemutakhiran menggunakan metode asimilasi data batimetri. Proses asimilasi dimulai dari data tersedia yang akan dimutakhirkan yaitu DEMNAS wilayah laut dengan resolusi spasial 6 arc-second diasimilasi menggunakan data pemeruman yang terbaru. Metode interpolasi pembentukan DEM menggunakan metode spline dengan tension 0,27. Tujuan dari peningkatan resolusi spasial dari DEMNAS wilayah laut menjadi 2 arc-second adalah untuk menjaga tingkat kedetailan model pada area-area yang sudah memiliki data pemeruman yang detail. Datum horizontal yang digunakan adalah WGS 1984 dan datum vertikal menggunakan datum mean sea level (MSL). Hasil pengujian menunjukan standar deviasi pada DEMNAS laut yang dimutakhirkan pada resolusi spasial 2 arc-second menunjukan hasil yang paling baik dengan standar deviasi 2,006 m. Sementara untuk DEMNAS Laut yang dimutakhirkan dengan resolusi 6 arc-second menghasilkan standar deviasi lebih rendah yaitu 7,108 m.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

scholarly journals Deterministic approach for multiple-source tsunami hazard assessment for Sines, Portugal

2015 ◽  
Vol 15 (11) ◽  
pp. 2557-2568 ◽  
Author(s):  
M. Wronna ◽  
R. Omira ◽  
M. A. Baptista
Keyword(s):  
Sea Level ◽  
Wave Height ◽  
Hazard Assessment ◽  
Test Site ◽  
Tsunami Hazard ◽  
Deterministic Approach ◽  
Flow Depth ◽  
Mean Sea Level ◽  
Tsunami Hazard Assessment ◽  
The Impact

Abstract. In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2.

scholarly journals Tropical cyclone simulations over Bangladesh at convection permitting 4.4 km & 1.5 km resolution

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hamish Steptoe ◽  
Nicholas Henry Savage ◽  
Saeed Sadri ◽  
Kate Salmon ◽  
Zubair Maalick ◽  
...  
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Sea Level ◽  
Tropical Cyclones ◽  
Weather Forecasting ◽  
Sea Level Pressure ◽  
Mean Sea Level ◽  
Level Pressure ◽  
Medium Range ◽  
Gust Speed

AbstractHigh resolution simulations at 4.4 km and 1.5 km resolution have been performed for 12 historical tropical cyclones impacting Bangladesh. We use the European Centre for Medium-Range Weather Forecasting 5th generation Re-Analysis (ERA5) to provide a 9-member ensemble of initial and boundary conditions for the regional configuration of the Met Office Unified Model. The simulations are compared to the original ERA5 data and the International Best Track Archive for Climate Stewardship (IBTrACS) tropical cyclone database for wind speed, gust speed and mean sea-level pressure. The 4.4 km simulations show a typical increase in peak gust speed of 41 to 118 knots relative to ERA5, and a deepening of minimum mean sea-level pressure of up to −27 hPa, relative to ERA5 and IBTrACS data. The downscaled simulations compare more favourably with IBTrACS data than the ERA5 data suggesting tropical cyclone hazards in the ERA5 deterministic output may be underestimated. The dataset is freely available from 10.5281/zenodo.3600201.

scholarly journals Flooding Conditions at Aveiro Port (Portugal) within the Framework of Projected Climate Change

2021 ◽  
Vol 9 (6) ◽  
pp. 595
Author(s):  
Américo Soares Ribeiro ◽  
Carina Lurdes Lopes ◽  
Magda Catarina Sousa ◽  
Moncho Gomez-Gesteira ◽  
João Miguel Dias
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Climate Change Impacts ◽  
Storm Surges ◽  
Historical Period ◽  
Return Periods ◽  
Wave Regime ◽  
Mean Sea Level ◽  
Sea Levels ◽  
Far Future

Ports constitute a significant influence in the economic activity in coastal areas through operations and infrastructures to facilitate land and maritime transport of cargo. Ports are located in a multi-dimensional environment facing ocean and river hazards. Higher warming scenarios indicate Europe’s ports will be exposed to higher risk due to the increase in extreme sea levels (ESL), a combination of the mean sea level, tide, and storm surge. Located on the west Iberia Peninsula, the Aveiro Port is located in a coastal lagoon exposed to ocean and river flows, contributing to higher flood risk. This study aims to assess the flood extent for Aveiro Port for historical (1979–2005), near future (2026–2045), and far future (2081–2099) periods scenarios considering different return periods (10, 25, and 100-year) for the flood drivers, through numerical simulations of the ESL, wave regime, and riverine flows simultaneously. Spatial maps considering the flood extent and calculated area show that most of the port infrastructures' resilience to flooding is found under the historical period, with some marginal floods. Under climate change impacts, the port flood extent gradually increases for higher return periods, where most of the terminals are at high risk of being flooded for the far-future period, whose contribution is primarily due to mean sea-level rise and storm surges.

scholarly journals Approaching Sea-Level Rise (SLR) Change: Strengthening Local Responses to Sea-Level Rise and Coping with Climate Change in Northern Mozambique

2021 ◽  
Vol 9 (2) ◽  
pp. 205
Author(s):  
Serafino Afonso Rui Mucova ◽  
Ulisses Miranda Azeiteiro ◽  
Walter Leal Filho ◽  
Carina Lurdes Lopes ◽  
João Miguel Dias ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Sea Level Rise ◽  
Sea Level ◽  
North Coast ◽  
Coastal Regions ◽  
Mean Sea Level ◽  
Representative Concentration Pathways ◽  
Local Responses ◽  
Ipcc Report ◽  
Global Estimates

Mean sea-level is expected to rise significantly by 2100 in all scenarios, including those compatible with the objectives of the Paris Climate Agreement. Global sea level rise projections indicate devastating implications for populations, ecosystem services and biodiversity. The implications of the sea-level rise (SLR) on low-lying islands and coastal regions and communities are substantial and require deep-rooted coping measures. In the absence of adequate responses for coping, Mozambique is expected to record huge losses, with an impact on the economy and development in many sectors of its coastal regions mainly in northern Mozambique. This research aimed to perform projections on SLR in Mozambique, and to understand its role and implications on the north coast of the country. SLR was estimated through the analysis of model outputs that support the global estimates of the fifth IPCC report near the Mozambican coast, for each of the four representative concentration pathways (RCPs) scenarios. Regional coastline retreat and coastal erosion were estimated through the results of global sandy coastlines projections developed by Vousdoukas. Mean sea-level rise projections indicate that regional estimates for the Mozambican coast are relative higher than global estimates (~0.05 m) for all representative concentration pathways (RCPs). Yet, we highlight significant differences in sea-level rises of 0.5 m, 0.7 m or 1.0 m by 2100 compared to the global mean. It is expected that with the increase in the mean sea level in the northern part of the Mozambican coast, erosive effects will increase, as well as the retreat of the coastline until 2100. With this, the tourism sector, settlements, ecosystem services and local populations are expected to be significantly affected by 2050, with increased threats in 2100 (RCP4.5, RCP8.5). Local responses for coping are proposed and properly discussed for the RCP4.5 and RCP8.5 scenarios through 2100.

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