The UN-GGCE International Workshop on the Integration of Terrestrial, Maritime, Built and Cadastral Domains with the theme Joining Land and Sea was carried out in Bogor from December 2nd-5th 2024. The workshop is designed to address the practical challenges, share and exchange knowledge, information and experience, and provide guidance for Member State representatives in the integration of land and ocean data and geospatial information into a unified geodetic reference framework. This is a critical advance in understanding and addressing environmental challenges such as sea level rise, land cover change, flooding, tsunamis, storm surges, and broader climate change impacts on coastal ecosystems and population centers. This approach offers a comprehensive perspective that enhances predictive capabilities, informs policymaking, and supports sustainable development.
In the United Nations context, integration across terrestrial, maritime, built and cadastral domains is essential to achieve the following Sustainable Development Goals (SDGs):
- SDG 6: Clean Water Sanitation. Ensuring availability and sustainability management of water and sanitation for all
- SDG 11: Sustainable Cities and Communities. Making cities inclusive, safe, resilient, and sustainable
- SDG 13: Climate Action. Taking urgent action to combat climate change and its impacts
- SDG 14: Life Below Water. Conserving and sustainably using the oceans, seas, and marine resources
The Panel Session of the Workshop is divided into 8 sessions as follows:
- Introduction and Setting the Scene
- Exploring Case studies around the Globe
- Joining Land and Sea using the Geoid
- Challenges and Issues
- Standards, Policies and Legal
- Geoid and Sea-Level Modelling
- Roadmap to Joining Land and Sea
Dr.rer.nat. Wiwin Windupranata, as a member of the Hydrography Research Group, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, delivered a speech entitled Development of Indonesian Tide Model. In his speech, he described the recent development of the Indonesian Tide Model based on altimetry satellites and tide gauge data.
The motivations for the development are the requirement for developing the accurate and seamless geoid and tidal datum model. Some improvements in tidal modelling compared to the existing global tide model are selecting optimum satellite combinations and utilizing along-track altimetry satellite data. The optimum altimetry satellite combination for the tide model is the combination of Topex/Jason Series, ENVISAT, and GFO. After verification with over 150 tide gauge data, the developed tide model produced an overall accuracy of 11.31 cm.
Example Result of Tide Modelling for M2, K1, and M4 components.
Based on the tide model, a tidal datum model was developed to calculate five tidal datum, as required in the Indonesian Geospatial Law (UU Nr. 4/2011). The datum are: (1) Highest Astronomical Tides (HAT), (2) Mean High Water Spring (MHWS), (3) Mean Sea Surface (MSS), (4) Mean Low Water Spring (MLWS), and (5) Lowest Astronomical Tide (LAT). The height tidal datum is calculated with refer to Mean Sea Surface, geoid and WGS84 Ellipsoid. After verification with over 120 tide gauge data, 8-11 cm accuracies were gained from the tidal datum model.
Example of HAT, MHWS, LAT and MLWS tidal datum model (referred to MSS).