Planning Study of Tide and Sea level in the SCS 6TH EAHC CHARTING AND HYDROGRAPHY COMMITTEE (CHC) MEETING 16TH to 18TH AUGUST 2017 TOKYO, JAPAN

Overview of the study Title : Planning study of Tides and Sea level in the SCS(South China Sea) Funding organization : KRISO Research period : from October to December, 2016 Budget : USD 40 M Research team : The Korean Society of Oceanography Major researchers Dr. KANG, Youngseung (CEO of Ocean R&S) Prof. CHO Yangki (Prof. of SNU Univ.) Mr. YANG Jigwan (Scientist of Ocean R&S) 2/19

Aims of Project Background International interest in the South China Sea Need to understand the ocean environment system Demand for tide and bathymetry data for safe navigation Ensure measures to respond to environmental risks due to long-term sea level rise due to global warming Need to operate an ocean numerical model for accurate understanding of the tidal system and ocean environment Select appropriate numerical models Review for establishing mean sea level and lowest astronomical tide 3/19

Overview The South China Sea (SCS) part of the western Pacific Ocean and is surrounded by many countries and islands 4/19

Overview Characteristics of SCS High requirements influenced by the Southeast Asia monsoon system surface ocean circulation is highly variable seabed is rich in minerals such as oil Sea level fluctuations may be greater than the global mean High requirements to standardize the tide and depth data according to the standard to unify the chart datum with one LAT value 5/19

Data configuration research In order to analyze the characteristics of the main water body and main ship routes of SCS it is necessary to acquire high quality observation data in addition to analyzing existing observation data 6/19

Data configuration research Ocean observation buoys should be selected based on easiness in installation and maintenance considering the characteristics of SCS Observation data obtained at ocean observation buoys can be utilized to identify the characteristics of ocean environment of the SCS as boundary condition and basic data for future ocean forecast model 7/19

Prioritization The priority of the port A criterion determined in consideration of importance, risk and socioeconomic demand, etc. among the ports under authority of each SCS neighboring country A criterion established for reviewing the urgency and importance of research on ports belonging to each country Hydrographic survey and water depth survey for major ports is different survey periods depending on the port 8/19

Prioritization In order to prioritize the study area, the following review process is necessary. Identification of current situation and problems of the hydrographic survey in the coastal waters of the SCS countries Determination of relative importance of ports and coastal areas and priority criteria by reviewing cases of the developed countries Re-verification of the relative importance and criteria through questionnaires on the hydrographic survey experts in each country Development of objective priority model applied to proven criteria Determination of the relative importance and prioritization of major ports in each country through objective priority model 9/19

Prioritization Six factors need to be reviewed very carefully to assess the high risk area Configuration of Sea Bottom : the port is located in a river mouth, and water depth changes significantly due to sediment input, construction of artificial ocean facilities, landfill and dredging Ocean Transportation : the port suffers from high ship traffic Ocean Accident : high occurrence of ship accident, presence of sunken ships, rocks and reefs Current Survey Data : past hydrographic survey results are few or repeat period is too long Ocean Environment & Ecosystem : natural scenery is excellent and ocean ecosystem needs to be protected Demand of Customer : need to collect opinions from port users 10/19

Suggestion of suitable numerical model In order to construct a system that reproduces and predicts the oceanography of a specific area, a proper numerical model should be selected 11/19

Suggestion of suitable numerical model For boundary conditions of the numerical model TOPEX / Poseidon altimetry data, tidal station data in the SCS and results from global models are utilized Numerical simulation longer than 18.6 years to include the nodal tidal cycle is necessary for estimation of astronomical tide Numerically stable models should be selected because complex tidal currents are generated due to sudden water depth changes in the target area 12/19

Suggestion of suitable numerical model Numerical models capable of nesting techniques used to simulate major ports in the SCS using tens of meters grid resolution 13/19

Suggestion of suitable numerical model As a result of comparisons of various ocean circulation models, ROMS (Regional Ocean Modeling System) model is considered to be most suitable for simulating tide and seasonally fluctuating ocean circulations in the SCS developed by Rutgers University in the USA capable of data assimilation. easy to improve the tide and sea level reproducibility of the SCS. The capability of nesting technique and parallel computing makes ROMS appropriate for simultaneous simulation of the whole SCS and a specific port in fine resolution 14/19

Example of observation and forecast system 15/19

Example of observation and forecast system 16/19

Project Planning In order to derive meaningful results of these studies data collection and analysis: Collecting and summarizing sea level and ocean current data of the SCS and analyzing them by a common harmonic method to identify the primary characteristics of tide in the SCS priority analysis: priority analysis for ports is performed including the first analysis result to select target area and perform the second analysis numerical model setup and validation: After the selection of a suitable numerical model for the SCS, perform model optimization process, validation experiment utilizing the data analyzed before and reproduction of the SCS tide perform long-term tide and sea level change simulation 17/19

Project Planning SCS Tide Research System Diagram 18/19

Project Planning Cost Estimate 19/19

Project Planning World Bank Group (WBG) Calling for a proposal for the World Bank's Strategic Research Program (SRP) SRP is supported by a multi-donor Trust Fund With the support of the WBG, carrying out the SCS tide studies and providing the results directly or indirectly to the countries and users

Recommendation ROK has done a planning study of tide and sea level in the SCS numerical model results are utilized for analysis of sea level change, setup of disaster information database, provision of safety navigation information, and establishment of common astronomical tide The budget for full scale study was estimated Hope that this study can be helpful for interested parties to prepare a proposal to funding organization for the full-scale study

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