A helicopter-borne geophysics campaign to gain a better understanding of Rodrigues' groundwater resources
At the request of the Regional Assembly of Rodrigues and the Ministry of Finance of Mauritius, the AFD is financing BRGM, the French geological survey, with funds from the French government, to carry out a helicopter-borne geophysical survey of Rodrigues over a period of around two weeks.
An improved characterisation of Rodrigues' groundwater resources
The aim of the measurement campaign is to gather fundamental data on the subsurface in order to better understand and manage the groundwater resources of Rodrigues, a small island of 109km2 located 583 km east of Mauritius in the Indian Ocean.
This geophysical acquisition programme will use the latest imaging technologies to acquire high-resolution geophysical data of Rodrigues Island. Initially intended to improve the characterisation of groundwater resources, the data collected can also be used for spatial planning and to assess seismic hazards and the risk of landslides.
3D visualisation of the subsurface of Rodrigues
With the exception of densely populated areas, which will not be overflown, this helicopter-borne geophysics operation will provide rapid, standardised data for the whole island. It will have no impact on the environment or health.
It will involve a helicopter equipped with a large octagonal antenna flying over Rodrigues at low altitude for a period of around two weeks. The measurements will provide imagery of the specific physical properties of soils and rocks, from the very near surface to several hundred metres below the surface. The data gathered will be processed using specialised geological software to generate a three-dimensional view of the subsurface.
This type of helicopter survey has already been tried out 16 times in France, including on Réunion Island ten years ago. The surveys have provided new knowledge of the subsurface and relevant information for addressing a range of societal issues.
The campaign is part of a study programme to improve knowledge of Rodrigues' groundwater resources, with a budget of €1.3 million financed by AFD via a Fund for Technical Expertise and Experience Transfers (FEXTE).
