1. 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

2. 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

3. 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

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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. Example of observation and forecast system
15/19

16. Example of observation and forecast system
16/19

17. 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

18. Project Planning
SCS Tide Research System Diagram
18/19

19. Project Planning
Cost Estimate
19/19

20. 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

21. 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

22. Thank you