3-D tsunami coastal hazard mapping in Sri Lanka by very-high resolution, airborne and spaceborne remote-sensing

Following an inter-Government agreement established between Italy and Sri Lanka in the aftermath of the great 2004 Indian Ocean tsunami, the operational project ‘HyperDEM’ was designed for mapping in 3-D the coastal areas of Sri Lanka, aimed to easing and speeding-up emergency mapping in tsunamiprone areas. The work, based on integration of airborne Lidar and spaceborne Radar campaigns, started in autumn 2005 and was accomplished in summer 2006 after acquisition of the outstanding data volume of ca. 2.7 TeraBytes. Some examples of results, and technical hints on methodological solutions adopted in solving operational problems are presented here. Upon completion of the work, the Government of Sri Lanka was provided with ca. 2’500 sq.km of Digital Elevation Models of the coastal areas, ca. 1’800 of which at the exceptional resolution of 1 metre and the elevation precision of 0.3 metres, and c.a. 700 at the resolution of 30 metres vs. an elevation precision of 2.6 metres.