Tonga advances 2026 Lidar baseline with coastal survey
Tonga is set to complete its first complete national Lidar baseline in 2026 after a coastal mapping survey covered Tongatapu and the Ha’apai island group from 21 March to 18 April 2026. The work gives the Kingdom of Tonga unified data it can use for coastal risk modelling, sea-level rise projections, disaster preparedness, infrastructure planning and long-term climate adaptation.
The survey was carried out by Fugro under the Tonga Coastal Resilience Project, which is funded by the Green Climate Fund and implemented by the United Nations Development Programme with the Government of Tonga. UNDP is also working with the Pacific Community to strengthen Tonga’s capacity to collect, manage, analyse, interpret and apply coastal and climate risk data.
Ha’apai and Tongatapu coverage
The 2026 flight path matters because it closes the last gap in Tonga’s national coverage. Tonga had previously undertaken a Lidar survey in 2012 over Tongatapu, Lifuka and Foa, and another in 2021 over ‘Eua, Vava’u, Tafahi and Niuatoputapu. The new survey over Tongatapu and the Ha’apai island group is designed to integrate those existing datasets into Tonga’s first complete unified national Lidar coverage.
That gives planners a single baseline rather than separate mapping sets from different years and different islands. For a country spread across low-lying coastal areas, the practical use is straightforward: scenario-based coastal risk maps and knowledge products can be built from the same data set instead of stitched together from partial coverage.
Ministry collaboration in Tonga
SPC and Fugro technical teams worked closely with the Mapping and Surveying Division in the Ministry of Lands, Survey, Planning and Natural Resources to ensure knowledge transfer and technical collaboration. The Ministry of Meteorology, Energy, Information, Disaster Management, Environment, Climate Change and Communications and the Ministry of Infrastructure participated in the coordination.
That coordination links the survey to the agencies most likely to use the results. Coastal mapping is not ending at data collection; the next step is how Tonga’s institutions apply the information in flood and coastal inundation modelling, safer infrastructure design and coastal zone management.
Green Climate Fund project
The Tonga Coastal Resilience Project places the survey inside a funded adaptation program rather than a one-off mapping exercise. The Green Climate Fund financing and UNDP implementation give Tonga a route to convert the 2026 survey into a national baseline that can support long-term planning.
The friction point is scale. Tonga is set to become one of the very few Pacific Island Countries with comprehensive national Lidar coverage in 2026, but the value of that achievement depends on whether the new baseline is absorbed into day-to-day planning by the ministries that took part in the coordination. The data is now in hand; the next step is whether Tonga turns it into the risk maps and planning tools the project is designed to produce.
